In this study an analytical model for open loop pulsating heat pipes (PHPs) is presented. The model predicts the effect of different parameters such as evaporator temperature, length of evaporator, filling ratio, number of turn and tube diameter on PHP's performance. The governing equations in two phase flow including mass, momentum and energy equations are solved for both one dimensional liqu...

  In this paper the numerical analysis of flow and time dependent heat transfer of micro-tube conveying nanofluid in laminar flow is investigated. In this study, convection heat transfer of nanofluid and base fluid and transient analysis for time-varying heat flux for time step of 0.0001 second are elucidated. It is observed that the pumping power of nanofluid flowing and the maximum temperatur...

In this article, turbulent flow heat transfer in the air gap between rotor and stator of a generator under nonhomogeneous heat flux is studied experimentally. The rotor consists of four symmetrical triangular grooves. The stator surface is smooth and does not include any grooves. The relative heat flux between the rotor and the stator is 1 to 3. Temperature and heat flux are measured locally at...

This paper reports the thermal performance of a new cylindrical solar collector based on an experimental investigation with this difference that instead of the collector tube with absorbent coating, coil into a spiral copper tube is placed in the center of the collector. The spiral shape of the tube, heat transfer without disruption or increase the heat transfer area, is increasing. In this cas...

The heat transfer for a non-Newtonian power-law fluid over a moving surface is investigated by applying a uniform suction/injection velocity profile. The flow is influenced by internal heat generation/absorption. The energy equation is solved at constant surface temperature condition. The Merk-Chao series is applied to obtain a set of ODEs instead of a complicated PDE. The converted ordinary diffe...

The article presents a practical technique for enhancing thermo-hydraulic performance of a circular tube. In this way, numerical method focusing on laminar tubular flow is used to compare the effectiveness of utilizing center-cleared twisted tapes instead of typical shape of short width tapes. Numerical analysis represented that using both center-cleared and typical shape of twisted tapes, Re e...

in this paper by the introduction of the basic equipment of a solar cooling system, solar hydrogen ammonia refrigeration system as a solar cooling technique will be discussed. using heat collector and absorption refrigeration allows us to use residual heat, for cooling, heating and producing hot water and boiling water .this research focuses on methods of heat transfer from the sun into the gen...

plate heat exchangers are widely used in industries due to their special characteristics, such as high thermal efficiency, small size, light weight, easy installation, maintenance, and cleaning. the purpose of this study is to consider the effect of depth, angle, and pitch of hemispheric chevrons on the convective heat transfer coefficient and pressure drop. in the simulation of the heat exchan...

One of the central problems in migration measurement arises as a consequence of the different sources of migration data. Most information regarding migration is obtained from population censuses or population registers that report migration data for a given time interval. Another source of migration data is the sample survey which may be designed to provide information about both migrants and...

A numerical study has been conducted to investigate the influence of fin pitch and relative humidity on the heat transfer performance of the fin-and-tube heat exchangers having plain fin geometry under dehumidifying conditions. The analysis is done using the ratio between the heat transfer coefficients in totally wet conditions and those in totally dry conditions using the appropriate correlati...