Numerical analysis is presented for transient buoyancy-induced natural convection from discrete heating inside a two-dimensional rectangular enclosure filled with porous medium. The study has been made for Rayleigh numbers of 100, 1000 and 10000 with an aspect ratio of 2. The left vertical wall is heated discretely to a constant high temperature and the right wall is cooled to a constant low te...

The explosive viscous liquid becomes inject to warhead by discharge system. The injection device is consisted of a piston to move down and leads the viscous fluid through the cylindrical pipe towards the end of the duct. Then the viscous fluid leads into a convergent path that will be injected to the warhead or other injection equipment. In this project, the path of viscous fluid flow is divide...

The conventional liquids have some limitations regarding the thermal properties. The nanoparticles addition is one of the techniques which can modify them. In this research, heat transfer coefficient (h) and pressure loss (Δp) of various nanofluids containing Al2O3, SiO2 and MgO nanoparticles dispersed in water in an annular tube with constant wall temperature were numerically considered. Accor...

A theoretical analysis of transient fluid flow and heat transfer in a triangular micro heat pipes (MHP) has been conducted to study the thermal response characteristics. By introducing the system identification theory, the quantitative evaluation of the MHP’s transient thermal performance is realized. The results indicate that the evaporation and condensation processes are both extended into th...

We calculate the quantum statistical force acting on a partition wall that divides a one dimensional box into two halves. The two half boxes contain the same (fixed) number of noninteracting bosons, are kept at the same temperature, and admit the same boundary conditions at the outer walls; the only difference is the distinct boundary conditions imposed at the two sides of the partition wall. T...

Molecular dynamics simulations are used for studying the contact angle of nanoscale sessile drops on a planar solid wall in a system interacting via the truncated and shifted Lennard-Jones potential. The entire range between total wetting and dewetting is investigated by varying the solid-fluid dispersive interaction energy. The temperature is varied between the triple point and the critical te...

1st of november 2005 2 Contents 1 Introduction 1 2 Estimation of temperature gradients in laminar flow through a cylindrical pipe-the assumption of a linear change in wall temperature with axial distance 1 2.1 Temperature distribution in a pipe with circular cross-section assuming a linear wall temperature variation with distance. .. .. 2 3 A ray-tracing analysis of the flow-meter error in the ...

    Given the need to increase the efficiency of heat transfer in thermal systems, especially systems using nanofluids in microscale and nanoscale heat transfer equipment ideas to improve their performance is very good.In present study, the flow and heat transfer of Water-Cu nanofluid in micro-tube with slip regime with constant wall heat flux numerically simulated with low Reynolds numbers. Sl...

A new methodology for preventing freezing damage beyond pre-specified boundaries during prostate cryosurgery is proposed herein. It consists of emitting controlled laser irradiation from the urethra, across the wall and into the prostate while conventional cryoprobes freeze the unwanted prostate tissue. The purpose of this methodology is to protect the urethral wall better and confine the desir...