ASTM E422-22

Standard Test Method for Measuring Net Heat Flux Using a Water-Cooled Calorimeter

SIGNIFICANCE AND USE
5.1 The purpose of this test method is to measure the net heat flux to a water-cooled surface for purposes of calibration of the thermal environment into which test specimens are placed for evaluation. The measured net heat flux is one of the important parameters for correlating the behavior of materials. If the calorimeter and holder size, shape, and surface finish are identical to that of the test specimen, the measured net heat flux to the calorimeter is presumed to be the same as that to the sample's heated surface. If the calorimeter configuration (holder size, shape, finish, etc.) is not identical to that of the test specimen, then the measurement results may need to be modified to account for those differences. See Appendix X1.  
5.2 The water-cooled calorimeter is one of several calorimeter concepts used to measure net heat flux. The prime drawback is its long response time, that is, the time required to achieve steady-state operation. To calculate energy added to the coolant water, accurate measurements of the rise in coolant temperature are needed, all energy losses should be minimized, and steady-state conditions must exist both in the thermal environment and fluid flow of the calorimeter.  
5.3 Regardless of the source of energy input to the water-cooled calorimeter surface (radiative, convective, or combinations thereof) the measurement is averaged over the surface-active area of the calorimeter. If the water-cooled calorimeter is used to measure only radiative flux or combined convective-radiative net heat flux rates, then the surface reflectivity of the calorimeter shall be measured over the wavelength region of interest (depending on the source of radiant energy). If nonuniformities exist in the gas stream, a large surface area water-cooled calorimeter would tend to smooth or average any variations. Consequently, it is advisable that the size of the calorimeter be limited to relatively small surface areas and applied to where the net heat flux is u...
SCOPE
1.1 This test method covers the measurement of a steady net heat flux to a given water-cooled surface by means of a system energy balance.  
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2022
• ICS: 17.200.10 - Heat. Calorimetry
• Technical Committee: E21 - Space Simulation and Applications of Space Technology
• Drafting Committee: E21.08 - Thermal Protection

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E422 − 22
Standard Test Method for
1
Measuring Net Heat Flux Using a Water-Cooled Calorimeter
This standard is issued under the fixed designation E422; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method covers the measurement of a steady net 3.1 Definitions—Refer to Terminologies E176 and E456 for
heat flux to a given water-cooled surface by means of a system
definitions of terms used in this test method.
energy balance.
3.2 Definitions of Terms Specific to This Standard:
1.2 Units—The values stated in SI units are to be regarded
3.2.1 absorbed heat flux, n—incident radiative heat flux less
2
as standard. No other units of measurement are included in this
the reflected radiative flux, W/m .
standard.
3.2.2 convective heat flux, n—the addition or loss of energy
1.3 This standard does not purport to address all of the
per unit area into the sensing surface due to convection, =
2
safety concerns, if any, associated with its use. It is the
h*(T -T ), W/m .
fs s
responsibility of the user of this standard to establish appro-
3.2.3 control volume, n—user defined volume over which an
priate safety, health, and environmental practices and deter-
energy balance is determined.
mine the applicability of regulatory limitations prior to use.
3.2.4 emitted heat flux, n—energy per unit area emitted from
1.4 This international standard was developed in accor-
4 2
a hot surface – ε*σ*T , W/m .
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2.5 incident radiative heat flux (irradiance; q ),
inc,r
Development of International Standards, Guides and Recom-
n—radiative heat flux (energy per unit area) impinging on the
mendations issued by the World Trade Organization Technical
surface of the calorimeter from an external environment,
2
Barriers to Trade (TBT) Committee.
W/m .
3.2.6 heat flux or energy flux, n—energy per unit area,
2. Referenced Documents
2
W/m .
2
2.1 ASTM Standards:
3.2.7 net heat flux or net energy flux, n—net energy divided
E176 Terminology of Fire Standards
by the sensing surface area transferred to the calorimeter face;
E230/E230M Specification for Temperature-Electromotive
it is equal to the [absorbed radiative heat flux + convective heat
Force (emf) Tables for Standardized Thermocouples
flux] – [re-radiation from the exposed surface].
E235 Specification for Type K and Type N Mineral-
3.2.8 reflected heat flux, n— that part of the incident
Insulated, Metal-Sheathed Thermocouples for Nuclear or
radiative flux that is not absorbed by or transmitted into the
for Other High-Reliability Applications
2
surface of the calorimeter, W/m .
E456 Terminology Relating to Quality and Statistics
E459 Test Method for Measuring Heat Transfer Rate Using
3.2.9 verified, n—the process of checking that a data acqui-
a Thin-Skin Calorimeter
sition channel correctly measures an input value, to a pre-set,
E3057 Test Method for Measuring Heat Flux Using Direc-
acceptable level condition defined by the user.
tional Flame Thermometers with Advanced Data Analysis
3.3 Symbols:
Techniques
2
A—sensing surface area of calorimeter, m
Cp—water specific heat, J/(kg-K)
2
h—convective heat transfer coefficient, W/m -K
1
This test method is under the jurisdiction of ASTM Committee E21 on Space
Simulation and Applications of Space Technology and is the direct responsibility of m—mass flow rate of coolant water, kg/sec
2
Subcommittee E21.08 on Thermal Protection.
q—heat flux, W/m
Current edition approved April 1, 2022. Published May 2022. Originally
T—temperature, K
approved in 1971. Last previous edition approved in 2016 as E422 – 05(2016). DOI:
10.1520/E0422-22.
T —calorimeter water inlet bulk temperature during
01
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
operation, K
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
T —calorimeter water exhaust bulk temperature during
Standards volume information, refer to the standard’s Document Summary page on 02
the ASTM website. operation, K
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E422 − 22
T —calorimeter water inlet bulk temperature before Interpretation of the data obtained is not within the scope of
1
operation, K this discussion; consequently, such ef
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E422 − 05 (Reapproved 2016) E422 − 22
Standard Test Method for
1
Measuring Net Heat Flux Using a Water-Cooled Calorimeter
This standard is issued under the fixed designation E422; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the measurement of a steady net heat flux to a given water-cooled surface by means of a system energy
balance.
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
E176 Terminology of Fire Standards
E230/E230M Specification for Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
E235 Specification for Type K and Type N Mineral-Insulated, Metal-Sheathed Thermocouples for Nuclear or for Other
High-Reliability Applications
E456 Terminology Relating to Quality and Statistics
E459 Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
E3057 Test Method for Measuring Heat Flux Using Directional Flame Thermometers with Advanced Data Analysis Techniques
3. Terminology
3.1 Definitions—Refer to Terminologies E176 and E456 for definitions of terms used in this test method.
3.2 Definitions of Terms Specific to This Standard:
2
3.2.1 absorbed heat flux, n—incident radiative heat flux less the reflected radiative flux, W/m .
1
This test method is under the jurisdiction of ASTM Committee E21 on Space Simulation and Applications of Space Technology and is the direct responsibility of
Subcommittee E21.08 on Thermal Protection.
Current edition approved April 1, 2016April 1, 2022. Published April 2016May 2022. Originally approved in 1971. Last previous edition approved in 20112016 as
E422 – 05 (2011).(2016). DOI: 10.1520/E0422-05R16.10.1520/E0422-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E422 − 22
3.2.2 convective heat flux, n—the addition or loss of energy per unit area into the sensing surface due to convection, = h*(T -T ),
fs s
2
W/m .
3.2.3 control volume, n—user defined volume over which an energy balance is determined.
4 2
3.2.4 emitted heat flux, n—energy per unit area emitted from a hot surface – ε*σ*T , W/m .
3.2.5 incident radiative heat flux (irradiance; q ), n—radiative heat flux (energy per unit area) impinging on the surface of the
inc,r
2
calorimeter from an external environment, W/m .
2
3.2.6 heat flux or energy flux, n—energy per unit area, W/m .
3.2.7 net heat flux or net energy flux, n—net energy divided by the sensing surface area transferred to the calorimeter face; it is
equal to the [absorbed radiative heat flux + convective heat flux] – [re-radiation from the exposed surface].
3.2.8 reflected heat flux, n— that part of the incident radiative flux that is not absorbed by or transmitted into the surface of the
2
calorimeter, W/m .
3.2.9 verified, n—the process of checking that a data acquisition channel correctly measures an input value, to a pre-set, acceptable
level condition defined by the user.
3.3 Symbols:
2
A—sensing surface area of calorimeter, m
Cp—water specific heat, J/(kg-K)
2
h—convective heat transfer coefficient, W/m -K
m—mass flow rate of coolant water, kg/sec
2
q—heat flux, W/m
T—temperature, K
T —calorimeter water inlet bulk temperature during operation, K
01
T —calorimeter water exhaust bulk
...