Thermal Analysis of a Microhotplate - An Experimental Study

In the present work, experimental and numerical thermal analysis of a microhotplate were performed to evaluate the heat transfer mechanism at small Rayleigh number (Ra). The convective and radiative heat transfer coefficient values were evaluated for microhotplate mounted over two different mounting positions (namely model-1 & model-2). At different heat generation (Q) values, it was found that the average convective coefficient value was less than 10[W]/[m
²
K], irrespective of the microhotplate mounting position. Comparison of both models at a similar Q (≃ 0.69W) value, reveals that the radiative heat transfer contribution was 33% & 68% for model-1 and model-2 respectively. Based on the results obtained in the present study, a correlation was developed using regression analysis for the convective Nusselt number in terms of Rayleigh number (8.84 × 10
^-4
≤ Ra ≤ 4.94 × 10
^-3
), and the convective Nusselt number obtained from the correlation and present study are within ±17%.