Experimental measurements and modeling of convective heat transfer in the transitional rarefied regime
- School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907 (United States)
We present experimental measurements and numerical simulations of convective heat transfer performance in the transitional rarefied regime for an isolated rectangular beam geometry. Experiments were performed using single crystalline silicon beam elements having width-to-thickness aspect ratios of 8.5 and 17.4. Devices were enclosed in a vacuum chamber and heated resistively using a DC power supply. A range of pressures corresponding to Knudsen numbers between 0.096 and 43.2 in terms of device thickness were swept, adjusting applied power to maintain a constant temperature of 50 K above the ambient temperature. Both parasitic electrical resistance associated with the hardware and radiative exchange with the environment were removed from measured data, allowing purely convective heat flux to be extracted. Numerical simulations were carried out deterministically through solution of the Ellipsoidal Statistical Bhatnagar-Gross-Krook collision model of the Boltzmann equation. Results agree with experimental data, revealing a strong coupling between dissipated heat flux and thermal stresses within the flowfield as well as a nonlinear transition between the free-molecule and continuum regimes.
- OSTI ID:
- 22390580
- Journal Information:
- AIP Conference Proceedings, Vol. 1628, Issue 1; Conference: 29. International Symposium on Rarefied Gas Dynamics, Xi'an (China), 13-18 Jul 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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