Rarefaction

About: Rarefaction is a research topic. Over the lifetime, 1852 publications have been published within this topic receiving 26943 citations.

Analysis of transient heat transfer through a collisionless gas enclosed between parallel plates

Abstract: Transient heat transfer through monatomic collisionless ideal gas enclosed between parallel walls analyzed for step change in one wall temperature

Propagation of rarefaction pulses in particulate materials with strain-softening behavior

Abstract: We investigate rarefaction waves in nonlinear periodic systems with a 'softening' power-law relationship between force and displacement to understand the dynamic behavior of this class of materials. A closed form expression describing the shape of the strongly nonlinear rarefaction wave is exact for n = 1/2 and agrees well with the shape and width of the pulses resulting from discrete simulations. A chain of particles under impact was shown to propagate a rarefaction pulse as the leading pulse in initially compressive impulsive loading in the absence of dissipation. Compression pulses generated by impact quickly disintegrated into a leading rarefaction solitary wave followed by an oscillatory train. Such behavior is favorable for metamaterials design of shock absorption layers as well as tunable information transmission lines for scrambling of acoustic information.

Navier-Stokes analysis of gaseous slip flow in long grooves

Abstract: A preconditioning compressible Navier-Stokes solver has been developed for microgroove flows. The pseudotime preconditioning with the rescaled AUSMD scheme is included to enhance convergence for the low-speed regime. The test cases contain flows through a two-dimensional microchannel and three-dimensional straight and spiral grooves. The calculations considering compressibility and rarefaction enhance numerical predictions. The nonlinearity of spanwise pressure gradients due to density variations is negated by the rarefaction. In addition, numerical estimation of pumping performance for a turbomolecular vacuum pump is strengthened by the inclusion of the spiral curvature effect.