This work analyzes how an over 99% efficient charging circuit and electrical offset fields enhance the coefficient of performance (COP) electrocaloric heat pumps, emerging technology with zero global warming potential. The COP is studied for Carnot-like cycles regarding material’s permittivity dissipation factor, system’s efficiency. Compared to Carnot limit, a relative material 50.4% calculate...

Hypersonic heating computations are still challenging due to difficulties in “A) robust capturing of shockwaves” and “B) accurate prediction of heating.” Based on our numerical survey for A), we found that the dissipation inside the numerical shock wave structure (where no physical or mathematical explanation is valid) must be proportional to Mach number, in contrast to Mach independent dissipa...

BACKGROUND Turbulence intensity, or hydromechanical stress, is a parameter that influences a broad range of processes in the fields of chemical engineering and biotechnology. Fermentation processes are often characterized by high agitation and aeration intensity resulting in high gas void fractions of up to 20% in large scale reactors. Very little experimental data on hydromechanical stress for...

We study the nonequilibrium fluctuation-dissipation theorem (FDT) in the glass phase of Bouchaud's trap model. We incorporate an arbitrary observable m and obtain its correlation and response functions in closed form. A limiting nonequilibrium FDT plot is approached at long times for most choices of m. In contrast to standard mean field models, however, the shape of the plot depends nontriviall...

J. Schulenborg(1),∗ R. B. Saptsov(2,3),∗ F. Haupt, J. Splettstoesser, and M. R. Wegewijs (1) Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-41298 Göteborg, Sweden (2) Institute for Theory of Statistical Physics, RWTH Aachen, 52056 Aachen, Germany (3) JARAFundamentals of Future Information Technology (4) JARA Institute for Quantum Information, RWTH Aac...

I examine the arguments which have been given for a quantum Langevin equation and a quantum fluctuation-dissipation relations. I argue that there is no reliable derivation of these relations beyond the simple (but important) case where all the equations of motion are linear.

We study the dynamics of two-dimensional surface gravity waves of fluid in a channel. The viscous dissipation in the bulk of the fluid is assumed to be negligible by comparing with the dissipation in the vicinity of the contact line. Capillarity effects are not considered. Dissipation in the vicinity of the contact line is described by contact line dissipation model suggested in de Ruijter et a...

This study investigates the local flow characteristics near droplet-droplet collisions by means of direct numerical simulation of isotropic cloudlike turbulence. The key finding is that, generally, droplets do not collide where they preferentially concentrate. Preferential concentration is found to happen as expected in regions of low enstrophy (vorticity magnitude), but collisions tend to take...