The paper presents a simplified (but not trivial) mathematical model of the interaction between the urine flow and the male urethra and bladder, respectively. Urine is assumed to be a Newtonian fluid. The flow is considered to be non-stationary, isothermal and turbulent. The urethra and bladder wall, featuring elastic properties, experience large displacements and strains. The dynamic forces ar...

Isothermal gas flows in microchannels is studied using the lattice Boltzmann method. A novel equation relating Knudsen number with relaxation time is derived. The slipvelocity on the solid boundaries is reasonably realized by combining the bounce-back reflection with specular reflection in a certain proportion. Predicted characteristics in a two-dimensional microchannel flow, including slip-vel...

6.1 Abstract The relaxation processes of metallic glasses are investigated by observing the changes in material properties associated with the transient stress strain response of specimens subjected to isothermal deformations. The properties studied include the isoconfigurational shear modulus, configurational enthalpy, and the anelastic strain of the material. Conventional glass relaxation pro...

Accretion flow in a contracting magnetized interstellar cloud was studied using magnetohydrodynamical simulations and a nested grid technique. First, the interstellar magnetized cloud experiences a “runaway collapse” phase, in which the central density increases drastically within a finite time scale. Finally, it enters an accretion phase, in which inflowing matter accretes onto a central high-...

Concentrated polymer solutions showing an Upper Critical Solution Temperature behavior are studied with respect to liquid-liquid demixing after a temperature quench. Models proposed in literature are compared and critically evaluated. These models describe the kinetics of liquid-liquid demixing accurately only in a limited region of quench depths. Growth of liquid-liquid demixed domains shows a...

In this paperwe have solved the hydrodynamic equations governing the spherically symmetric isothermal accretion (wind) onto (away from) compact objects using various pseudo-Schwarzschild potentials.These solutions are essentially one parameter solutions in a sense that all relevant dynamical as well as thermodynamic quantities for such a flow could be obtained (with the assumption of a one-temp...

Abstract A new second order theoretical model of the combined interaction of externally applied electric and magnetic fields and viscous incompressible fluid flows has been rewritten as a system of first order partial differential equations. The system was solved using a least-squares finite element model on an unstructured grid. The numerical algorithm is very stable and accurate. The accuracy...

The work presents a numerical methodology to simulate the dynamic behavior of reed type valves of reciprocating compressors used in refrigeration. A one-degree of freedom model is adopted for the reed motion and a finite volume method is employed to obtain the flow field through the valve. The valve dynamics and the time dependent flow field are coupled and solved simultaneously. As a first ste...

A Monte Carlo algorithm to simulate the isothermal recrystallization process of snow is presented. The snow metamorphism is approximated by two mass redistribution processes: surface diffusion and sublimation-deposition. The algorithm is justified and its parametrization is determined. The simulation results are compared to experimental data, in particular, the temporal evolution of the specifi...

We present special Newton-multigrid techniques for stationary incompressible nonlinear flow models discretised by the high order LBB-stable Q2P1 element pair. We treat the resulting nonlinear and the corresponding linear discrete systems by a fully coupled monolithic approach to maintain high accuracy and robustness, particularly with respect to different rheological behaviour but also regardin...