SIST-TP CEN/CLC/TR 17603-31-12:2021

Space Engineering - Thermal design handbook - Part 12: Louvers

Thermal louvers are thermal control surfaces whose radiation characteristics can be varied in order to
maintain the correct operating temperature of a component subject to cyclical changes in the amount
of heat that it absorbs or generates.
The design and construction of louvers for space systems are described in this Part 12 and a clause is
also dedicated to providing details on existing systems.
The Thermal design handbook is published in 16 Parts
TR 17603-31-01 Part 1 Thermal design handbook – Part 1: View factors
TR 17603-31-01 Part 2 Thermal design handbook – Part 2: Holes, Grooves and Cavities
TR 17603-31-01 Part 3 Thermal design handbook – Part 3: Spacecraft Surface Temperature
TR 17603-31-01 Part 4 Thermal design handbook – Part 4: Conductive Heat Transfer
TR 17603-31-01 Part 5 Thermal design handbook – Part 5: Structural Materials: Metallic and
Composite
TR 17603-31-01 Part 6 Thermal design handbook – Part 6: Thermal Control Surfaces
TR 17603-31-01 Part 7 Thermal design handbook – Part 7: Insulations
TR 17603-31-01 Part 8 Thermal design handbook – Part 8: Heat Pipes
TR 17603-31-01 Part 9 Thermal design handbook – Part 9: Radiators
TR 17603-31-01 Part 10 Thermal design handbook – Part 10: Phase – Change Capacitors
TR 17603-31-01 Part 11 Thermal design handbook – Part 11: Electrical Heating
TR 17603-31-01 Part 12 Thermal design handbook – Part 12: Louvers
TR 17603-31-01 Part 13 Thermal design handbook – Part 13: Fluid Loops
TR 17603-31-01 Part 14 Thermal design handbook – Part 14: Cryogenic Cooling
TR 17603-31-01 Part 15 Thermal design handbook – Part 15: Existing Satellites
TR 17603-31-01 Part 16 Thermal design handbook – Part 16: Thermal Protection System

Raumfahrttechnik - Handbuch für thermisches Design - Teil 12: Luftschlitze

Ingénierie spatiale - Manuel de conception thermique - Partie 12: Persiennes

Vesoljska tehnika - Priročnik o toplotni zasnovi - 12. del: Žaluzije

General Information

• Status: Published
• Public Enquiry End Date: 26-May-2021
• Publication Date: 23-Aug-2021
• ICS: 49.140 - Space systems and operations
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 19-Aug-2021
• Due Date: 24-Oct-2021
• Completion Date: 24-Aug-2021
• Mandate: M/496 - Mandate addressed to CEN, CENELEC and ETSI to develop standardisation regarding space industry (Phase 3 of the process)
• Ref Project: CEN/CLC/TR 17603-31-12:2021 - Space Engineering - Thermal design handbook - Part 12: Louvers

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN/CLC/TR 17603-31-12:2021
01-oktober-2021
Vesoljska tehnika - Priročnik o toplotni zasnovi - 12. del: Žaluzije
Space Engineering - Thermal design handbook - Part 12: Louvers
Raumfahrttechnik - Handbuch für thermisches Design - Teil 12: Luftschlitze
Ingénierie spatiale - Manuel de conception thermique - Partie 12: Persiennes
Ta slovenski standard je istoveten z: CEN/CLC/TR 17603-31-12:2021
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
SIST-TP CEN/CLC/TR 17603-31-12:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/CLC/TR 17603-31-12:2021


TECHNICAL REPORT
CEN/CLC/TR 17603-31-
12
RAPPORT TECHNIQUE

TECHNISCHER BERICHT

August 2021
ICS 49.140

English version

Space Engineering - Thermal design handbook - Part 12:
Louvers
Ingénierie spatiale - Manuel de conception thermique - Raumfahrttechnik - Handbuch für thermisches Design -
Partie 12 : Persiennes Teil 12: Blenden


This Technical Report was approved by CEN on 28 June 2021. It has been drawn up by the Technical Committee CEN/CLC/JTC 5.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
























CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2021 CEN/CENELEC All rights of exploitation in any form and by any means Ref. No. CEN/CLC/TR 17603-31-12:2021 E
reserved worldwide for CEN national Members and for
CENELEC Members.

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Table of contents
European Foreword . 7
1 Scope . 8
2 References . 9
3 Terms, definitions and symbols . 10
3.1 Terms and definitions . 10
3.2 Symbols . 10
4 General introduction . 15
5 Components of a louver . 16
5.1 Blades . 16
5.2 Actuators . 18
5.2.1 Bimetals . 18
5.2.2 Bellows . 24
5.2.3 Bourdons . 35
5.3 Sensors . 37
5.3.1 Sensor location . 37
5.3.2 Coupling options . 38
5.4 Structural elements . 38
5.4.1 Actuator housing . 38
5.4.2 Frames . 38
6 Ideal louvers . 40
6.1 Sun-light operation. 40
6.1.1 Introduction . 40
6.1.2 Heat rejection capability . 40
6.1.3 Effective absorptance . 43
6.1.4 Effective emittance . 46
6.2 Shadow operation . 52
6.2.1 Introduction . 52

6.2.2 Radiosity and temperature field of the blades. 53
6.2.3 Heat transfer through the louver . 55
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7 Existing systems . 66
7.1 Summary table . 66
7.2 Ats louvers . 76
7.2.1 Introduction . 76
7.2.2 Analytical calculations . 76
7.2.3 Tests . 80
7.3 Nimbus louvers . 83
7.3.1 Introduction . 83
7.3.2 Louvers of the sensory subsystem . 83
7.3.3 Louver of the control subsystem . 84
7.3.4 Flight performance . 86
7.4 Snias louvers . 87
7.4.1 Introduction . 87
7.4.2 Analytical calculations . 88
7.4.3 Tests . 95
7.4.4 The Bourdon tube used as an actuator in the SNIAS Louver system . 98
Bibliography . 104

Figures
Figure 5-1: Relative linear thermal expansion vs. temperature in the case of Invar. T =
0
273 K. From THE MOND NICKEL CO [35]. . 19
Figure 5-2: Relative linear thermal expansion vs. temperature in the case of brasses. T
0
= 273 K. After Baldwin (1961) [3]. . 20
Figure 5-3: Relative linear thermal expansion vs. temperature in the case of austenitic
steels. T = 273 K. After Zapffe (1961) [39]. . 20
0
Figure 5-4: Relative linear thermal expansion vs. temperature in the case of Nimonic
alloys. T = 273 K. After WIGGIN & Co. (1967) [38]. 21
0
Figure 5-5: Relative linear thermal expansion vs. temperature for different alloys. T =
0
273 K. After Baldwin (1961) [3], Zapffe (1961) [39], WIGGIN Co. (1967)
[38]. . 21
Figure 5-6: Difference of temperature, ∆T, vs. angle of rotation of the free end, θ, for
several values of the sensitivity, X. After Martin & Yarworth (1961) [21],
KAMMERER (1971) [16]. . 22
Figure 5-7: Sensitivity vs. ratio L/t, for different values of K . After Martin & Yarworth
c
(1961) [21], KAMMERER (1971) [16]. . 23
3
Figure 5-8: Dimensionless ratio M/K F ∆TL vs. L/t, for several values of w/t. After
c c
Martin & Yarworth (1961) [21], KAMMERER (1971) [16]. . 24
Figure 5-9: Values of α and β vs. ratio a/b for different cross sections of the Bourdon
tube. After Trylinski (1971) [37]. . 36
Figure 5-10: Ratio F/F vs. Bourdon initial coiling angle, ψ . Calculated by the compiler. . 37
0 0
3

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Figure 6-1: Geometry of the blade-baseplate system . 40
Figure 6-2: Heat rejection capability, q, vs. blade angle, θ, for several values of the sun
angle, φ. From FAIRCHILD HILLER (1972) [10]. . 42
Figure 6-3: Heat rejection capability, q, vs. blade angle, θ, for several values of the sun
angle, φ. From Parmer & Stipandic (1968) [27]. . 43
Figure 6-4: Effective absorptance, α , vs. blade angle, θ, for several values of the sun
eff
angle, φ. After FAIRCHILD HILLER (1972) [10]. . 45
Figure 6-5: Effective absorptance, α , vs. blade angle, θ, for several values of the sun
eff
angle, φ. After Parmer & Stipandic (1968) [27]. . 46
Figure 6-6: Effective emittance, ε , vs. blade angle, θ. After FAIRCHILD HILLER
eff
(1972) [10]. . 48
Figure 6-7: Effective emittance, ε , vs. blade angle, θ. After Parmer & Stipandic (1968)
eff
[27]. . 49
Figure 6-8: Effective emittance, ε , vs. blade angle, θ, for several values of the
eff
baseplate emittance, ε . ε has been numerically calculated by using the
BP eff
1
ε
BP
ε = (1−B *)dβ
following expression. . 50
eff
∫
1− ε
BP
0
Figure 6-9: Effective emittance, ε , vs. blade angle, θ, for several values of the blades
eff
emittance, ε . ε has been numerically calculated by using the following
B eff
1
ε
BP
expression. ε = (1−B *)dβ . 51
eff
∫
1− ε
BP
0
Figure 6-10: Effective emittance, ε , vs. blade angle, θ, for several b/L values. ε has
eff eff
been numerically calculated by using the following expression.
1
ε
BP
ε = (1−B *)dβ . 52
eff
∫
1− ε
BP 0
Figure 6-11: Schematic diagram of a louver for shadow operation. . 53
Figure 6-12: Schematic diagram of the louver array showing the coordinates and the
significant geometrical characteristics. . 54
Figure 6-13: Dimensionless radiosity, B*, of the blades for several values of the blade
angle, θ. From Plamondon (1964) [28]. . 55
Figure 6-14: Dimensionless temperature, T*, of the blades for several values of the
blade angle, θ. From Plamondon (1964) [28]. . 55
Figure 6-15: Function f(θ) vs. blade angle θ. After Parmer & Buskirk (1967)a [25]. . 57
Figure 6-16: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0.87. Calculated
B BP I
by the compiler. . 58
Figure 6-17: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 59
Figure 6-18: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 60
4

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Figure 6-19: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 61
Figure 6-20: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 62
Figure 6-21: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 63
Figure 6-22: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. εB = 0,05, εBP = εI = 0,87. Calculated
by the compiler. . 64
Figure 6-23: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, θ. ε = 0,05, ε = ε = 0,87. Calculated
B BP I
by the compiler. . 65
Figure 7-1: Effective emittance, ε , based on area of the large unit, vs. blade angle, θ,
eff
for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. 78
Figure 7-2: Effective absorptance, α , vs. blade angle, θ, for several values of the sun
eff
angle, φ, for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 79
θ, for several values of the sun
Figure 7-3: Heat rejection capability, q, vs. blade angle,
angle, φ, for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 80
Figure 7-4: Effective absorptance, α , vs. sun angle, φ, for several values of the blade
eff
angle, θ, for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 81
Figure 7-5: Heat rejection capability, q, vs. sun angle, φ, for ATS spacecraft. From
Michalek, Stipandic & Coyle (1972) [24]. . 82
Figure 7-6: Effective emittance vs. blade angle, θ, and baseplate temperature, TBP, for
sensory subsystem of NIMBUS spacecraft. From London (1967) [20]. . 84
Figure 7-7: Schematic blade geometry for diffuse body radiation analysis. Louvers of
the control subsystem. NIMBUS spacecraft. From London (1967) [20]. . 85
Figure 7-8: Effective emittance, ε , vs. blade angle, θ, for the control subsystem of
eff
NIMBUS spacecraft. From London (1967) [20]. . 85
Figure 7-9: Effective emittance, ε , vs. baseplate temperature, T , for the control
eff BP
subsystem of NIMBUS spacecraft. From London (1967) [20]. . 86
Figure 7-10: Comparison of NIMBUS 1 and 2 control subsystem panel temperatures,
T , vs. orbital position. From London (1967) [20]. . 86
p
Figure 7-11: Overall dimensions of SNIAS louver. Not to scale. . 87
Figure 7-12: Effective emittance, ε , vs. blade angle, θ, for the SNIAS louver system.
eff
From Redor (1972) [29]. . 89
Figure 7-13: Effective absorptance, α , vs. blade angle, θ, for several values of the sun
eff
angle, φ. SNIAS louver system. From Redor (1972) [29]. . 91
Figure 7-14: Heat rejection capability, q, vs. blade angle, θ, for several values of the
sun angle, φ. SNIAS louver system. From Redor (1972) [29]. 93
Figure 7-15: Maximum blade temperature, T , vs. blade angle, θ, for several values of
B
the sun angle, φ. SNIAS louver system. From Redor (1972) [29]. . 95
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Figure 7-16: Effective emittance, εeff, vs. blade angle, θ, for the louver system of
SNIAS. Solid line: From Redor (1972) [29]. Dashed line: From Croiset &
Leroy (1973) [8]. . 96
Figure 7-17: Heat rejection capability, q, vs. blade angle, θ, for several values of the
sun angle, φ. SNIAS louver system. Solid line: From Redor (1972) [29].
Dashed line: From Croiset & Leroy (1973) [8]. 97
Figure 7-18: Temperature-pressure characteristic of the Bourdon spiral. From Reusser
et al. (1973) [30]. . 100
Figure 7-19: Performance of a Bourdon actuating a single blade. After Reusser et al.
(1973) [30]. . 101
Figure 7-20: Ratios (TBP−T)/(TBP−TOL) and Q/Q0 vs. time, τ. After Reusser et al. (1973)
[30]. . 103

Tables
Table 5-1: Blade Characteristics of Existing Louver Assemblies R: Rectangular, T:
Trapezoidal . 16
Table 5-2: Materials Used . 19
Table 5-3: Typical Alloy Used in Bellows D: Deposited, F: Formed, W: Welded . 25
Table 5-4: Typical Nonmetallic Materials Used in Bellows . 27
Table 5-5: Typical Fluids Used in Bellows . 28
Table 5-6: Bellows Convolutions and Relevant Characteristics . 28
Table 5-7: Spring Rate for Several Bellows . 30
Table 5-8: Frequency of Bellows Vibration . 31
Table 5-9: Characteristics of Convoluted Bellows . 32
Table 7-1: Assumed Values of the Optical Properties of the Surfaces for the First
Computer program . 77
Table 7-2: Assumed Values of the Optical Properties of the Surfaces for the Second
Computer program . 77
Table 7-3: Ideal Optical Properties of the NIMBUS Louvers Surfaces . 83
Table 7-4: Optical Characteristics of the Surfaces of SNIAS Louver. . 87
Table 7-5: Effective Absorptance α , for Several Values of Sun Angle, φ, and Blade
eff
Angle, θ. . 90
Table 7-6: Heat Rejection Capability, q, for Several Values of Sun Angle, φ, and Blade
Angle, θ. . 92
Table 7-7: Maximum Blade Temperature, T , for Several Values of Sun Angle, φ, and
B
Blade Angle, θ. . 94
Table 7-8: Several Characteristics of the Bourdon Spiral . 98
Table 7-9: Several Parameters of the Bourdon Spiral . 99

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European Foreword
This document (CEN/CLC/TR 17603-31-12:2021) has been prepared by Technical Committee
CEN/CLC/JTC 5 “Space”, the secretariat of which is held by DIN.
It is highlighted that this technical report does not contain any requirement but only collection of data
or descriptions and guidelines about how to organize and perform the work in support of EN 16603-
31.
This Technical report (TR 17603-31-12:2021) originates from ECSS-E-HB-31-01 Part 12A.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such
patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and
the European Free Trade Association.
This document has been developed to cover specifically space systems and has therefore precedence
over any TR covering the same scope but with a wider domain of applicability (e.g.: aerospace).
7

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1
Scope
Thermal louvers are thermal control surfaces whose radiation characteristics can be varied in order to
maintain the correct operating temperature of a component subject to cyclical changes in the amount
of heat that it absorbs or generates.
The design and construction of louvers for space systems are described in this Part 12 and a clause is
also dedicated to providing details on existing systems.

The Thermal design handbook is published in 16 Parts
TR 17603-31-01 Thermal design handbook – Part 1: View factors
TR 17603-31-02 Thermal design handbook – Part 2: Holes, Grooves and Cavities
TR 17603-31-03 Thermal design handbook – Part 3: Spacecraft Surface Temperature
TR 17603-31-04 Thermal design handbook – Part 4: Conductive Heat Transfer
TR 17603-31-05 Thermal design handbook – Part 5: Structural Materials: Metallic and
Composite
TR 17603-31-06 Thermal design handbook – Part 6: Thermal Control Surfaces
TR 17603-31-07 Thermal design handbook – Part 7: Insulations
TR 17603-31-08 Thermal design handbook – Part 8: Heat Pipes
TR 17603-31-09 Thermal design handbook – Part 9: Radiators
TR 17603-31-10 Thermal design handbook – Part 10: Phase – Change Capacitors
TR 17603-31-11 Thermal design handbook – Part 11: Electrical Heating
TR 17603-31-12 Thermal design handbook – Part 12: Louvers
TR 17603-31-13 Thermal design handbook – Part 13: Fluid Loops
TR 17603-31-14 Thermal design handbook – Part 14: Cryogenic Cooling
TR 17603-31-15 Thermal design handbook – Part 15: Existing Satellites
TR 17603-31-16 Thermal design handbook – Part 16: Thermal Protection System

8

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2
References
EN Reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS System - Glossary of terms

All other references made to publications in this Part are listed, alphabetically, in the Bibliography.

9

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3
Terms, definitions and symbols
3.1 Terms and definitions
For the purpose of this Standard, the terms and definitions given in ECSS-S-ST-00-01 apply.
3.2 Symbols
2
Clause 5: bellows effective area, [m ]
A
Clause 7: contact surface (bourdon sensing element),

2
[m ]
−
2
radiosity, [W.m ]
B
4
dimensionless radiosity, B* = B/σT
B*
bellows innermost diameter, [m]
Di
bellows outermost diameter, [m]
Do
−2
modulus of elasticity, [N.m ]
E
−
1
flexibility, [m.Pa ]
F
− −
2 1
coil force constant, [N.m .Angular degrees ]
Fc
−
2
energy flux impinging on the unit area, [W.m ]
H
−
2
heat flux to the skin arriving from outside, [W.m ]
J
−
1
bellows spring rate, [N.m ]
K
−
1
coil deflection constant, [angular degrees, K ]
Kc
Clause 5: coil active length, [m]
L
Clause 5: length of all convolutions in bellows, [m]

Clause 6: louver blade spacing, [m]

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length of a single convolution in bellows measured
Lc
along the surface, [m]
torsional moment of a coil, [N.m]
M
fluid pressure, [Pa]
P
proportionality limit pressure in a bourdon, [Pa]
Pt
heat transfer to the fluid within the bourdon, [J]
Q
heat transfer to the fluid within the bourdon after an
Q0
infinitely large time, [J]
equivalent thermal resistance of the louver system, it
R(θ)
is a function of the optical properties of blades, and
inner skin surface, but for a given system R depends
only on the blade angle
coiling radius of a bourdon, [m]
R0
mean radius of the bellows, [m]
Rm
−
2
heat flux from the space to the skin, [W.m ]
S
−
2
solar constant, S0 = 1353 W.m
S0
temperature, [K]
T
bourdon filling fluid temperature, [K]
TC
reference temperature, [K]
T0
temperature differential, [K], ∆T = T−T0
∆T
starting fluid temperature, [K]
T0L
skin temperature, [K]
TS
4 4
local dimensionless temperature, T* = T /T BP
T*
3
inside volume of bellows, [m ]
V
−
1
sensitivity of a bimetal, [angular degrees, K ]
X
semi-major axis of the bourdon tube cross section, [m]
a
Clause 5: semi-minor axis of the bourdon tube section,
b
[m]
Clause 6: louver blade width, [m]

11

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Clause 5: numerical coefficient given in Table 5-7
c
under additional data
− −
1 1
Clause 7: fluid specific heat, [J.kg .K ]

defined as f(θ) = 1 - [1/R(θ)]
f(θ)
−
1
fundamental natural frequency, [s ]
fn=1
total thermal conductance of a bourdon (sensing
h
− −
2 1
element plus fluid, [W.m .K ]
length of a given metallic strip when the temperature
l
is T [m]
live length of the bellows, [m]

length of a given metallic strip when the temperature
l0
is T0, [m]
mass of bellows active convolutions, [kg]
ma
mass of one convolution, [kg]
mc
mass of fluid trapped in active length at rest, [kg]
mfa
2 2
mfa = ρL[0,262(Do +DoDi)-0,524Di ]
mass of liquid within the bellows, [kg]. ml = ρAl
ml
mass on bellows free end, [kg]
m1
bellows mass, [kg]
m2
−
2
louver heat rejection capability, [W.m ]
q
−
2
heat rejection capability for zero solar input, [W.m ]
qshadow
thickness of the strip of the coil, [m]
t
wall thickness for bellows or bourdon tube, [m]

width of the strip of the coil, [m]
w
coordinate along the louver baseplate, [m]
x
Coordinates along the outer and inner faces of the
y,z
blade, [m]
Φ sun angle, [angular degrees]
α absorptance
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numerical coefficient which appears in the expression

of bourdon flexibility
solar absorptance
αs
α spectral absorptance
λ
−
1
β Clause 5: linear thermal expansion coefficient, [K ]
Clause 5: numerical coefficient which appears in that

expression of bourdon flexibility
Clause 6: Dimensionless coordinate along the louver

baseplate, β = x/L
linear thermal expansion coefficient of the high
βH
−
1
expansibility component of a bimetal, [K ]
linear thermal expansion coefficient of the low
βL
−
1
expansibility component of a bimetal, [K ]
ε hemispherical total emittance
emittance of the skin inner surface
εI
emittance of the skin outer surface
εs
dimensionless coordinates, η = y/L, ζ = z/L
η,ζ
Clause. 5: angular deflection of a coil, [angular
θ
degrees]
Clause 6: louver blade angle, [angular degrees]

poisson's ratio
ν
−
...

SLOVENSKI STANDARD
kSIST-TP FprCEN/CLC/TR 17603-31-12:2021
01-maj-2021
Vesoljska tehnika - Priročnik za toplotno zasnovo - 12. del: Žaluzije
Space Engineering - Thermal design handbook - Part 12: Louvers
Raumfahrttechnik - Handbuch für thermisches Design - Teil 12: Luftschlitze
Ingénierie spatiale - Manuel de conception thermique - Partie 12: Persiennes
Ta slovenski standard je istoveten z: FprCEN/CLC/TR 17603-31-12
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
kSIST-TP FprCEN/CLC/TR 17603-31- en,fr,de
12:2021
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST-TP FprCEN/CLC/TR 17603-31-12:2021

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kSIST-TP FprCEN/CLC/TR 17603-31-12:2021


TECHNICAL REPORT
FINAL DRAFT
FprCEN/CLC/TR 17603-
RAPPORT TECHNIQUE
31-12
TECHNISCHER BERICHT


March 2021
ICS 49.140

English version

Space Engineering - Thermal design handbook - Part 12:
Louvers
Ingénierie spatiale - Manuel de conception thermique - Raumfahrttechnik - Handbuch für thermisches Design -
Partie 12: Persiennes Teil 12: Luftschlitze


This draft Technical Report is submitted to CEN members for Vote. It has been drawn up by the Technical Committee
CEN/CLC/JTC 5.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a Technical Report. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a Technical Report.




















CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2021 CEN/CENELEC All rights of exploitation in any form and by any means Ref. No. FprCEN/CLC/TR 17603-31-12:2021 E
reserved worldwide for CEN national Members and for
CENELEC Members.

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Table of contents
European Foreword . 7
1 Scope . 8
2 References . 9
3 Terms, definitions and symbols . 10
3.1 Terms and definitions . 10
3.2 Symbols . 10
4 General introduction . 15
5 Components of a louver . 16
5.1 Blades . 16
5.2 Actuators . 18
5.2.1 Bimetals . 18
5.2.2 Bellows . 24
5.2.3 Bourdons . 35
5.3 Sensors . 37
5.3.1 Sensor location . 37
5.3.2 Coupling options . 38
5.4 Structural elements . 38
5.4.1 Actuator housing . 38
5.4.2 Frames . 38
6 Ideal louvers . 40
6.1 Sun-light operation. 40
6.1.1 Introduction . 40
6.1.2 Heat rejection capability . 40
6.1.3 Effective absorptance . 43
6.1.4 Effective emittance . 46
6.2 Shadow operation . 52
6.2.1 Introduction . 52
6.2.2 Radiosity and temperature field of the blades. 53
6.2.3 Heat transfer through the louver . 55
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7 Existing systems . 66
7.1 Summary table . 66
7.2 Ats louvers . 76
7.2.1 Introduction . 76
7.2.2 Analytical calculations . 76
7.2.3 Tests . 80
7.3 Nimbus louvers . 83
7.3.1 Introduction . 83
7.3.2 Louvers of the sensory subsystem . 83
7.3.3 Louver of the control subsystem . 84
7.3.4 Flight performance . 86
7.4 Snias louvers . 87
7.4.1 Introduction . 87
7.4.2 Analytical calculations . 88
7.4.3 Tests . 95
7.4.4 The Bourdon tube used as an actuator in the SNIAS Louver system . 98
Bibliography . 104

Figures
Figure 5-1: Relative linear thermal expansion vs. temperature in the case of Invar. T =
0
273 K. From THE MOND NICKEL CO [35]. . 19
Figure 5-2: Relative linear thermal expansion vs. temperature in the case of brasses. T
0
= 273 K. After Baldwin (1961) [3]. . 20
Figure 5-3: Relative linear thermal expansion vs. temperature in the case of austenitic
steels. T = 273 K. After Zapffe (1961) [39]. . 20
0
Figure 5-4: Relative linear thermal expansion vs. temperature in the case of Nimonic
alloys. T = 273 K. After WIGGIN & Co. (1967) [38]. 21
0
Figure 5-5: Relative linear thermal expansion vs. temperature for different alloys. T =
0
273 K. After Baldwin (1961) [3], Zapffe (1961) [39], WIGGIN Co. (1967)
[38]. . 21
Figure 5-6: Difference of temperature, T, vs. angle of rotation of the free end, , for
several values of the sensitivity, X. After Martin & Yarworth (1961) [21],
KAMMERER (1971) [16]. . 22
Figure 5-7: Sensitivity vs. ratio L/t, for different values of K . After Martin & Yarworth
c
(1961) [21], KAMMERER (1971) [16]. . 23
3
Figure 5-8: Dimensionless ratio M/K F TL vs. L/t, for several values of w/t. After
c c
Martin & Yarworth (1961) [21], KAMMERER (1971) [16]. . 24
Figure 5-9: Values of  and  vs. ratio a/b for different cross sections of the Bourdon
tube. After Trylinski (1971) [37]. . 36
Figure 5-10: Ratio F/F vs. Bourdon initial coiling angle,  . Calculated by the compiler. . 37
0 0
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Figure 6-1: Geometry of the blade-baseplate system . 40
Figure 6-2: Heat rejection capability, q, vs. blade angle, , for several values of the sun
angle, . From FAIRCHILD HILLER (1972) [10]. . 42
Figure 6-3: Heat rejection capability, q, vs. blade angle, , for several values of the sun
angle, . From Parmer & Stipandic (1968) [27]. . 43
Figure 6-4: Effective absorptance,  , vs. blade angle, , for several values of the sun
eff
angle, . After FAIRCHILD HILLER (1972) [10]. . 45
Figure 6-5: Effective absorptance,  , vs. blade angle, , for several values of the sun
eff
angle, . After Parmer & Stipandic (1968) [27]. . 46
Figure 6-6: Effective emittance,  , vs. blade angle, . After FAIRCHILD HILLER
eff
(1972) [10]. . 48
Figure 6-7: Effective emittance,  , vs. blade angle, . After Parmer & Stipandic (1968)
eff
[27]. . 49
Figure 6-8: Effective emittance,  , vs. blade angle, , for several values of the
eff
baseplate emittance,  .  has been numerically calculated by using the
BP eff
1

BP
following expression.   1 B *d . 50
eff

1 
BP
0
Figure 6-9: Effective emittance,  , vs. blade angle, , for several values of the blades
eff
emittance,  .  has been numerically calculated by using the following
B eff
1

BP
expression.   1 B *d . 51
eff

1 
BP
0
Figure 6-10: Effective emittance,  , vs. blade angle, , for several b/L values.  has
eff eff
been numerically calculated by using the following expression.
1

BP
  1 B *d
. 52
eff

1 
BP 0
Figure 6-11: Schematic diagram of a louver for shadow operation. . 53
Figure 6-12: Schematic diagram of the louver array showing the coordinates and the
significant geometrical characteristics. . 54
Figure 6-13: Dimensionless radiosity, B*, of the blades for several values of the blade
angle, . From Plamondon (1964) [28]. . 55
Figure 6-14: Dimensionless temperature, T*, of the blades for several values of the
blade angle, . From Plamondon (1964) [28]. . 55
Figure 6-15: Function f() vs. blade angle . After Parmer & Buskirk (1967)a [25]. . 57
Figure 6-16: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0.87. Calculated
B BP I
by the compiler. . 58
Figure 6-17: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 59
Figure 6-18: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 60
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Figure 6-19: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 61
Figure 6-20: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 62
Figure 6-21: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 63
Figure 6-22: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 64
Figure 6-23: Net heat transfer through the louver, q, vs. baseplate temperature, T , for
BP
several values of the blade angle, .  = 0,05,  =  = 0,87. Calculated
B BP I
by the compiler. . 65
Figure 7-1: Effective emittance,  , based on area of the large unit, vs. blade angle, ,
eff
for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. 78
Figure 7-2: Effective absorptance,  , vs. blade angle, , for several values of the sun
eff
angle, , for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 79
Figure 7-3: Heat rejection capability, q, vs. blade angle, , for several values of the sun
angle, , for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 80
Figure 7-4: Effective absorptance,  , vs. sun angle, , for several values of the blade
eff
angle, , for ATS spacecraft. From Michalek, Stipandic & Coyle (1972) [24]. . 81
Figure 7-5: Heat rejection capability, q, vs. sun angle, , for ATS spacecraft. From
Michalek, Stipandic & Coyle (1972) [24]. . 82
Figure 7-6: Effective emittance vs. blade angle, , and baseplate temperature, T , for
BP
sensory subsystem of NIMBUS spacecraft. From London (1967) [20]. . 84
Figure 7-7: Schematic blade geometry for diffuse body radiation analysis. Louvers of
the control subsystem. NIMBUS spacecraft. From London (1967) [20]. . 85
Figure 7-8: Effective emittance,  , vs. blade angle, , for the control subsystem of
eff
NIMBUS spacecraft. From London (1967) [20]. . 85
Figure 7-9: Effective emittance,  , vs. baseplate temperature, T , for the control
eff BP
subsystem of NIMBUS spacecraft. From London (1967) [20]. . 86
Figure 7-10: Comparison of NIMBUS 1 and 2 control subsystem panel temperatures,
T , vs. orbital position. From London (1967) [20]. . 86
p
Figure 7-11: Overall dimensions of SNIAS louver. Not to scale. . 87
Figure 7-12: Effective emittance,  , vs. blade angle, , for the SNIAS louver system.
eff
From Redor (1972) [29]. . 89
Figure 7-13: Effective absorptance,  , vs. blade angle, , for several values of the sun
eff
angle, . SNIAS louver system. From Redor (1972) [29]. . 91
Figure 7-14: Heat rejection capability, q, vs. blade angle, , for several values of the
sun angle, . SNIAS louver system. From Redor (1972) [29]. 93
Figure 7-15: Maximum blade temperature, T , vs. blade angle, , for several values of
B
the sun angle, . SNIAS louver system. From Redor (1972) [29]. . 95
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Figure 7-16: Effective emittance,  , vs. blade angle, , for the louver system of
eff
SNIAS. Solid line: From Redor (1972) [29]. Dashed line: From Croiset &
Leroy (1973) [8]. . 96
Figure 7-17: Heat rejection capability, q, vs. blade angle, , for several values of the
sun angle, . SNIAS louver system. Solid line: From Redor (1972) [29].
Dashed line: From Croiset & Leroy (1973) [8]. 97
Figure 7-18: Temperature-pressure characteristic of the Bourdon spiral. From Reusser
et al. (1973) [30]. . 100
Figure 7-19: Performance of a Bourdon actuating a single blade. After Reusser et al.
(1973) [30]. . 101
Figure 7-20: Ratios (T T)/(T T ) and Q/Q vs. time, . After Reusser et al. (1973)
BP BP OL 0
[30]. . 103

Tables
Table 5-1: Blade Characteristics of Existing Louver Assemblies R: Rectangular, T:
Trapezoidal . 16
Table 5-2: Materials Used . 19
Table 5-3: Typical Alloy Used in Bellows D: Deposited, F: Formed, W: Welded . 25
Table 5-4: Typical Nonmetallic Materials Used in Bellows . 27
Table 5-5: Typical Fluids Used in Bellows . 28
Table 5-6: Bellows Convolutions and Relevant Characteristics . 28
Table 5-7: Spring Rate for Several Bellows . 30
Table 5-8: Frequency of Bellows Vibration . 31
Table 5-9: Characteristics of Convoluted Bellows . 32
Table 7-1: Assumed Values of the Optical Properties of the Surfaces for the First
Computer program . 77
Table 7-2: Assumed Values of the Optical Properties of the Surfaces for the Second
Computer program . 77
Table 7-3: Ideal Optical Properties of the NIMBUS Louvers Surfaces . 83
Table 7-4: Optical Characteristics of the Surfaces of SNIAS Louver. . 87
Table 7-5: Effective Absorptance  , for Several Values of Sun Angle, , and Blade
eff
Angle, . . 90
Table 7-6: Heat Rejection Capability, q, for Several Values of Sun Angle, , and Blade
Angle, . . 92
Table 7-7: Maximum Blade Temperature, T , for Several Values of Sun Angle, , and
B
Blade Angle, . . 94
Table 7-8: Several Characteristics of the Bourdon Spiral . 98
Table 7-9: Several Parameters of the Bourdon Spiral . 99

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European Foreword
This document (FprCEN/CLC/TR 17603-31-12:2021) has been prepared by Technical Committee
CEN/CLC/JTC 5 “Space”, the secretariat of which is held by DIN.
This document is currently submitted to the Vote on TR.
It is highlighted that this technical report does not contain any requirement but only collection of data
or descriptions and guidelines about how to organize and perform the work in support of EN 16603-
31.
This Technical report (FprCEN/CLC/TR 17603-31-12:2021) originates from ECSS-E-HB-31-01 Part 12A.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such
patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and
the European Free Trade Association.
This document has been developed to cover specifically space systems and has therefore precedence
over any TR covering the same scope but with a wider domain of applicability (e.g.: aerospace).
This document is currently submitted to the CEN CONSULTATION.

7

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1
Scope
Thermal louvers are thermal control surfaces whose radiation characteristics can be varied in order to
maintain the correct operating temperature of a component subject to cyclical changes in the amount
of heat that it absorbs or generates.
The design and construction of louvers for space systems are described in this Part 12 and a clause is
also dedicated to providing details on existing systems.

The Thermal design handbook is published in 16 Parts
TR 17603-31-01 Thermal design handbook – Part 1: View factors
TR 17603-31-02 Thermal design handbook – Part 2: Holes, Grooves and Cavities
TR 17603-31-03 Thermal design handbook – Part 3: Spacecraft Surface Temperature
TR 17603-31-04 Thermal design handbook – Part 4: Conductive Heat Transfer
TR 17603-31-05 Thermal design handbook – Part 5: Structural Materials: Metallic and
Composite
TR 17603-31-06 Thermal design handbook – Part 6: Thermal Control Surfaces
TR 17603-31-07 Thermal design handbook – Part 7: Insulations
TR 17603-31-08 Thermal design handbook – Part 8: Heat Pipes
TR 17603-31-09 Thermal design handbook – Part 9: Radiators
TR 17603-31-10 Thermal design handbook – Part 10: Phase – Change Capacitors
TR 17603-31-11 Thermal design handbook – Part 11: Electrical Heating
TR 17603-31-12 Thermal design handbook – Part 12: Louvers
TR 17603-31-13 Thermal design handbook – Part 13: Fluid Loops
TR 17603-31-14 Thermal design handbook – Part 14: Cryogenic Cooling
TR 17603-31-15 Thermal design handbook – Part 15: Existing Satellites
TR 17603-31-16 Thermal design handbook – Part 16: Thermal Protection System

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2
References
EN Reference Reference in text Title
EN 16601-00-01 ECSS-S-ST-00-01 ECSS System - Glossary of terms

All other references made to publications in this Part are listed, alphabetically, in the Bibliography.

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3
Terms, definitions and symbols
3.1 Terms and definitions
For the purpose of this Standard, the terms and definitions given in ECSS-S-ST-00-01 apply.
3.2 Symbols
2
Clause 5: bellows effective area, [m ]
A
Clause 7: contact surface (bourdon sensing element),

2
[m ]

2
radiosity, [W.m ]
B
4
dimensionless radiosity, B* = B/T
B*
bellows innermost diameter, [m]
Di
bellows outermost diameter, [m]
Do

2
modulus of elasticity, [N.m ]
E

1
flexibility, [m.Pa ]
F
 
2 1
coil force constant, [N.m .Angular degrees ]
Fc

2
energy flux impinging on the unit area, [W.m ]
H

2
heat flux to the skin arriving from outside, [W.m ]
J

1
bellows spring rate, [N.m ]
K

1
coil deflection constant, [angular degrees, K ]
Kc
Clause 5: coil active length, [m]
L
Clause 5: length of all convolutions in bellows, [m]

Clause 6: louver blade spacing, [m]

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length of a single convolution in bellows measured
Lc
along the surface, [m]
torsional moment of a coil, [N.m]
M
fluid pressure, [Pa]
P
proportionality limit pressure in a bourdon, [Pa]
Pt
heat transfer to the fluid within the bourdon, [J]
Q
heat transfer to the fluid within the bourdon after an
Q0
infinitely large time, [J]
equivalent thermal resistance of the louver system, it
R()
is a function of the optical properties of blades, and
inner skin surface, but for a given system R depends
only on the blade angle
coiling radius of a bourdon, [m]
R0
mean radius of the bellows, [m]
Rm

2
heat flux from the space to the skin, [W.m ]
S

2
solar constant, S0 = 1353 W.m
S0
temperature, [K]
T
bourdon filling fluid temperature, [K]
TC
reference temperature, [K]
T0
temperature differential, [K], T = TT0
T
starting fluid temperature, [K]
T0L
skin temperature, [K]
TS
4 4
local dimensionless temperature, T* = T /T BP
T*
3
inside volume of bellows, [m ]
V

1
sensitivity of a bimetal, [angular degrees, K ]
X
semi-major axis of the bourdon tube cross section, [m]
a
Clause 5: semi-minor axis of the bourdon tube section,
b
[m]
Clause 6: louver blade width, [m]

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Clause 5: numerical coefficient given in Table 5-7
c
under additional data
 
1 1
Clause 7: fluid specific heat, [J.kg .K ]

defined as f() = 1 - [1/R()]
f()

1
fundamental natural frequency, [s ]
fn=1
total thermal conductance of a bourdon (sensing
h
 
2 1
element plus fluid, [W.m .K ]
length of a given metallic strip when the temperature
l
is T [m]
live length of the bellows, [m]

length of a given metallic strip when the temperature
l0
is T0, [m]
mass of bellows active convolutions, [kg]
ma
mass of one convolution, [kg]
mc
mass of fluid trapped in active length at rest, [kg]
mfa
2 2
mfa = L[0,262(Do +DoDi)-0,524Di ]
mass of liquid within the bellows, [kg]. ml = Al
ml
mass on bellows free end, [kg]
m1
bellows mass, [kg]
m2

2
louver heat rejection capability, [W.m ]
q

2
heat rejection capability for zero solar input, [W.m ]
qshadow
thickness of the strip of the coil, [m]
t
wall thickness for bellows or bourdon tube, [m]

width of the strip of the coil, [m]
w
coordinate along the louver baseplate, [m]
x
Coordinates along the outer and inner faces of the
y,z
blade, [m]
 sun angle, [angular degrees]
 absorptance
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numerical coefficient which appears in the expression

of bourdon flexibility
solar absorptance
s
 spectral absorptance


1
 Clause 5: linear thermal expansion coefficient, [K ]
Clause 5: numerical coefficien
...