SAE J2609 pdf download
SAE J2609 pdf download.Multi-Dimensional Thermal Properties of lnsulated Heat Shield Material Systems.
This test method measures the system material properties of an insulated formed heat shield under in- vehicle conditions. While the material properties of the individual components can often be determined via existing test methods, the system properties of the entire composite is typicaly much harder to ascertain (especially for mulb4ayer shields). System material properties include thermal Conductivity in the lateral in-ane (x) direction, thermal conductivity through the thickness or perpendicular (y), surface emissivity on the top and bottom sides of the shield and specific heal of the shield material.
1.1 All properties are determined tot the entire shielding material specimen as a composite of the entire structure. Properties are determined using a testing apparatus that allows for Iwo-dimensional heat flow through the specimen. Due to this, the material property results from this test method may not aee with One-dimensional heat flow type testing methods, but is represenlatNe of most heat shield materials performance tested with a cenlrakzed heat Source. Therefore, material property results from this test method may be more suited for multi-cmensiorial analytical stucbes.
1.2 This standard sets forth the general guidelines to construct and operate the testing apparatus to acquire a satisfactory set of test data. Designs conforming to this standard are included and must nof be deviated from for sensitivity reasons that will be discussed xi more detail Later. Test pai ameters that cannot be deviated from etdude. but are not limited to; specimen size, distance between the source and the specrien, source diameter and environmental conditions around the apparatus.
1.3 This method ultimately determines the shield material properties by using the test data along with an analytical scheme, see Section 81.
1.4 ThIs test method will evaluate both isotropic and anisotropic insulated shielding materials. This may also include multi-layer stiiekng structures which include embossed/corrugated sdids. porous, fibrous, granulated and coated materials.
1.5 Limitations
This test method does have hmrtations WI the type of insulated shielding materials that can be evaluated. However, many of the hmitations apply to materials that would not typically be suitable in a heat shielding function or the poperties can be derived by seripler one-dimensional hot plate methods (SAE J1 361, ASTM C 177).
Limitations indude:
a) Materials where the radiant transmissivlty through the material cannot be assumed as zero. Materials of this type are dassilied as translucent or transparent.
b) Materials that do not have an insLdating diaracterislic in at least one axis; (i.e.. single wall stamped metal shielding). This includes shielding materials where lateral thermal conductivity (x) and thermal conductivity through the thickness (y) are the same and considered high (In the order of 25 W/.mC) when compared to metalic materials. These types of single sheet metalic shields are not indudod WI the standard because the properties of these matenals are typically well known and do not require a procedure to determine them.
c) Materials where the lateral thermal condoctivity (x) is less than the thermal conductivity through the thiclness (y).
d) Testing exposes the shielding material to temperatures up to 250’C. Materials with limits below this level shoiid not use this method.
1.6 Safety
This method Wwolves a lest apparatus that exposes the operator to very high temperatures. This
standard does not purport to address all of the safely concerns. If any, associated with Its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and
determine the applicabdity of regLdatory bmitatioris prior to use.
1.7 The attached Appendix A provides a detailed discussion of the analytical technique used in
calculating the insulated shielding material properties from the test data. The Appendix A also presents the theoretical sensitivity study of the analytical method.
1.6 This test method requires two specific pieces ci test .istnimentation. A portable emissometer as ouThned in ASTM C1371 and a radicisity meter or infrared camera with the abdity to set the emissivity to 1.0.
