新型空腔式黑体辐射源设计及不确定度评定

为促进恒温槽内空腔黑体与载热工质之间的热交换,提出了一种附加被动扰流装置的黑体空腔辐射源的设计方法.通过新设计的空腔外壁微扰动结构,对载热工质施加干扰,使流体热边界层破坏并再生,利用热边界层初段传热强度高的原理强化传热.此设计既可以提高换热系数,又可以增加换热面积,减少空腔与载热工质达到热平衡所需的时间.对新型的耳温计...

Design and Uncertainty Evaluation for New Blackbody Source

In order to enhance the heat transfer between the blackbody cavity and the heat carrier, a new design of cavity blackbody source with passive spoiler is proposed. With the newly designed micro-disturbance structure on the outer wall of the cavity, the thermal boundary layer of the working fluid is disturbed to destroy and regenerate, so the heat transfer is enhanced by the principle of high heat transfer intensity in the initial section of the thermal boundary layer. The new design can not only improve the heat transfer coefficient, but also increase the heat transfer area, which can reduce the time required for the cavity and the heat carrier to achieve thermal balance. The experimental study and uncertainty evaluation of the new blackbody radiation source of the ear thermometer are carried out. The results show that the expanded uncertainty of the new design cavity blackbody is U=0.05℃(k=2), and the equilibration time can be reduced by more than 15%.