Gas kinetic forces on thin plates in the presence of thermal gradients.
Gases perturbed by thermal gradients exert forces on surfaces exposed to the molecular bombardment. We calculate the force on thin plates with temperature differences between the opposite faces in dense gases. Using the Chapman-Enskog method we obtain an analytical formula that accounts for normal and shear stresses on the plate edge. We predict a force per unit length of the plate perimeter up to 6.6x10(-8) N/mm per degree Kelvin of temperature difference in air. The present result is compared with experimental data from the literature finding an excellent agreement in those cases where experimental conditions and procedures permit comparison. The proposed analytical formula provides an effective tool for calculating forces in microstructures and nanostructures affected by temperature inequalities.
Scandurra
Marco
M
Center for Theoretical Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. scandurr@lns.mit.edu
Iacopetti
Fabrizio
F
Colona
Paolo
P