用户名: 密码:    忘记密码   注册   在线充值
用水冷热量计测量热通量的标准试验方法  
 【英文标准名称】  Standard Test Method for Measuring Heat Flux Using a Water-Cooled Calorimeter
 【原文标准名称】  用水冷热量计测量热通量的标准试验方法
 【标准号】  ASTM E422-2005
 【标准状态】  Active
 【国别】  
 【发布日期】  2005
 【实施或试行日期】  
 【发布单位】  美国材料与试验协会(US-ASTM)
 【起草单位】  E21.08
 【标准类型】  (Test Method)
 【标准水平】  ()
 【中文主题词】  热通量;热量计;航空航天运输;测量技术
 【英文主题词】  calorimeter; heat flux; heat transfer rate
 【摘要】  

The purpose of this test method is to measure the heat flux to a water-cooled surface for purposes of calibration of the thermal environment into which test specimens are placed for evaluation. If the calorimeter and holder size, shape, and surface finish are identical to that of the test specimen, the measured heat flux to the calorimeter is presumed to be the same as that to the samplersquo;heated surface. The measured heat flux is one of the important parameters for correlating the behavior of materials.

The water-cooled calorimeter is one of several calorimeter concepts used to measure 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.

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 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 heat-flux is uniform. Where large samples are tested it is recommended that a number of smaller diameter water-cooled calorimeters be used (rather than one large unit). These shall be located across the heated surface such that a heat-flux distribution can be described. With this, a more detailed heat-flux measurement can be applied to the specimen test and more information can be deduced from the test.

1.1 This test method covers the measurement of a steady heat flux to a given water-cooled surface by means of a system energy balance.

1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

 【中国标准分类号】  A42
 【国际标准分类号】  17_200_10
 【页数】  5P.;A4
 【正文语种】  
索取全文
标准全文由山东省标准化研究院向您提供(不能使用知网账号下载全文),需向山东省标准化研究院支付相关费用后,方可获得标准。

 

       

标准间关联  
本领域专利与科技成果  
本标准研制背景
本标准应用动态
所涉核心技术研究动态
京ICP证040431号 互联网出版许可证 新出网证(京)字008号 京公网安备11010802014875号
© 2014中国知网(CNKI) 《中国学术期刊(光盘版)》电子杂志社有限公司
服务热线:400-810-9888 订卡热线:800-810-6613
在线咨询:http://help.cnki.net 客服中心:http://service.cnki.net 电子邮件:help@cnki.net