Rarefied gas flow around a double-plate induced by temperature difference

Abstract Radiometric phenomena are expected to be applied to lifting or propelling high-altitude aerospace craft, however, the temperature difference between both sides of the radiometric plate is too small to produce a substantial force. In this work, we proposed a double-plate structure as an alternative to the radiometric plate. The flow around the double-plate was studied for a wide range of plate temperatures, gap-to-radius ratios and Knudsen numbers with molecular kinetic theory and the direct simulation Monte Carlo (DSMC). Kinetic analysis reveals that the normalized force and heat fluxes acting on the plates could be well approximated by exponential-decay functions of the gap-to-radius ratio when the gap-to-radius ratio is smaller than 2. Pressure distributions on the plates demonstrate that the gas-plate interactions combine dynamics of rarefied flow, continuum flow and the geometrical effect. Dependences of the normalized forces and heat fluxes on Kn , gap distance, and plate temperatures were studied in dimensionless form and compared with those of radiometric flow. Analytical formulations were developed to evaluate the forces and heat flux acting on the double-plate quickly. The double-plate could produce a force which is larger than its weight at altitudes around 70 k m if the parameters were properly selected.