The relativistic kinetic theory of the phonon gas in superfluids is developed. The technique of the derivation of macroscopic balance equations from microscopic equations of motion for individual particles is applied to an ensemble of quasi-particles. The necessary expressions are constructed in terms of a Hamilton function of a (quasi-)particle. A phonon contribution into superfluid dynamic pa...

In this research, the effects of parameters include tool rotational and traverse speeds were investigated on heat generation and material flow during friction stir welding of Ti-6Al-4V alloy with computational fluid dynamics (CFD) method. Simulation results showed that with increasing of tool rotational and decreasing tool traverse speed, the more frictional heat generates which causes formatio...

Complex heat transfer phenomena (including unsteady state conduction, convection and solidification processes) occur in steel belt conveyer sulfur granulating method. Numerical simulation of this technique is performed via a comprehensive and multifaceted one dimensional model. Since the air situated between the adjacent sulfur pastilles is essentially stagnant, therefore, the surface tempe...

In this article, the vibrational behavior of a spinning cylindrical thick shell carrying spring- mass systems and conveying viscos fluid flow under various temperature distributions is investigated. This structure rotates about axial direction and the formulations include the coriolis and centrifugal effects. In addition, this system is conveying viscous fluid, and the related force is calculat...

One of the major industry problems is the flow boiling, where reaching to the critical heat flux (CHF) condition can lead to a temperature jump and damage of the systems. In the present study, the effects of a uniform change in tube diameter on subcooled flow boiling and CHF was numerically investigated. The Euler-Euler model was used to investigate the relationship between the two liquid and v...

the monolithic catalytic converter is still the main pollution control device for modern vehicles in order to reach the ever-increasing legislative demands for low emission standards. the catalytic converters require a large expansion from the exhaust pipe to the front face of the monolith. unfortunately, packaging constraints often do not permit the use of long diffusers. hence, flow separatio...

In this research, the effects of parameters include tool rotational and traverse speeds were investigated on heat generation and material flow during friction stir welding of Ti-6Al-4V alloy with computational fluid dynamics (CFD) method. Simulation results showed that with increasing of tool rotational and decreasing tool traverse speed, the more frictional heat generates which causes formatio...

In this paper, size distribution of nano-bubbles was measured by the reliable and fast method of laser diffraction technique. Nano-bubbles were produced using a nano-bubble generator designed and made based on hydrodynamic cavitation phenomenon in Venturi tubes. A Central Composite Design with Response Surface Methodology was used to conduct a five factor, five level factorial experimental desi...