Transient heat transfer measurements using thermochromic liquid crystal. Part 2: Experimental uncertainties

✍ Scribed by J.Michael Owen; Paul J Newton; Gary D Lock

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 143 KB
• Volume: 24
• Category: Article
• ISSN: 0142-727X
• DOI: 10.1016/s0142-727x(02)00207-2

✦ Synopsis

In Part 1 of this two-part paper, an ''exponential-series technique'' was used to calculate heat transfer coefficient, h, for the socalled slow transient case where it is not possible to generate a step-change in the air temperature. Small uncertainties in the measured temperatures can, however, create large uncertainties in the calculated value of h, and the amplification parameter, U h , is defined as the ratio of the relative uncertainty in h to the relative uncertainties in the temperatures. Using an uncertainty analysis, theoretical expressions for U h are found for the slow transient case, and these expressions are in excellent agreement with values computed using a Monte Carlo method. The results provide guidance in the selection of design parameters for an experiment and for the calculation and minimisation of the uncertainty in h.