sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. but square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

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...

This study examines both high-flux flow boiling and critical heat flux (CHF) under highly subcooled conditions using FC-72 as working fluid. Experiments were performed in a horizontal flow channel that was heated along its bottom wall. High-speed video imaging and photomicrographic techniques were used to capture interfacial features and reveal the sequence of events leading to CHF. At about 80...

A one-dimensional divergence of the monochromatic heat flux for wall-affected attenuating thingas, is developed from general considerations. Here Ebl. K~ cy and r, respectively denote the monochromatic values of the emissive power, absorption coefficient of gas, wall emissivity and optical thickness; , E, is the second exponential integ-ral, y the -4' coordinate normal to boundary. infinite geo...

In the Heat Engineering Chair of Poznan University of Technology, there have been investigations carried out for the last 10 years, of heat transfer processes on the wall of a single action internal combustion engine. Investigations of local heat transfer coefficients were carried out in different combustion conditions and the engine was propelled with a methanecarbon dioxide mixture (65% of CH...

Heat transfer from the internal surfaces of a vertical pipe to the adjacent air gives rise to the air flow establishment within the pipe. With the aim of optimizing the convective air flow rate in a vertical pipe, the details of the flow and thermal fields were investigated in the present study. Conservation equations of mass, momentum, and energy were solved numerically using simple implicit f...

h = heat transfer coefficient q = heat flux from the wall of evaporator to refrigerant Tw =Temperature at the wall of evaporator Tf = Temperature of the refrigerant kal = Conductivity of aluminum t = Thickness of evaporator M& = Mass flow rate of refrigerant Cp = Constant-pressure specific heat of refrigerant Tsat = Saturation temperature of refrigerant Tin = Temperature of refrigerant at inlet...

Abstract—This paper presents the heat and mass driven natural convection succession in a Darcy thermally stratified porous medium that embeds a vertical semi-infinite impermeable wall of constant heat flux and concentration. The scale analysis of the system determines the two possible maps of the heat and mass driven natural convection sequence along the wall as a function of the process parame...

A technique for determining the heat transfer on the far surface of a wall based on measuring the heat transfer and temperature on the near wall is presented. Although heat transfer measurements have previously been used to augment temperature measurements in inverse heat conduction methods, the sensors used alter the heat flow through the surface, disturbing the very quantity that is desired t...

In this paper conjugated heat transfer in thermal entrance region through the sinusoidal wavy channel has been investigated. The fluid flow is assumed to be laminar, steady state, incompressible, and hydrodynamically fully developed. A constant heat flux is assumed to be applied on the outer edge of the channel wall. In this study the governing equations including continuity, momentum and energ...