This article presented a numerical investigation of supercritical heat transfer of hydrocarbon fuel in a series of horizontal tubes with different diameters. It has been carried out by solving Reynolds averaging equations of mass, momentum and energy with the LS low-Reynolds number turbulence model using the pressure-based segregated solver based on the finite volume method. For the purpose of ...

Convective heat transfer of MgO-water nanofluid in a microchannel heat sink is experimentally investigated in various concentrations of 0.01, 0.05, 0.1, and 0.6 wt%. The microchannel consisted of 48 parallel rectangular cross section channels with the height of 800 µm, width of 524 µm and length of 52 mm. A well stability duration (ca. 1 month) was resulted by a 180 min ultra-sonication of the ...

We consider a one-dimensional one-phase Stefan problem for a semi-infinite substance. We suppose that there is a transient heat flux at the fixed face and the thermal coefficients are constant. The goal of this paper is to determine the behavior of the free boundary and the temperature by changing the thermal coefficients. We use the maximum principle in order to obtain properties of monotony w...

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...

It has been predicted that the heat capacity of superfluid He will diverge strongly at a depressed transition temperature in the presence of a constant heat flux, Q. We have built a cell to measure this effect, and have taken preliminary measurements at various heat flux values. Our data indicate an enhancement of the heat capacity that varies as a function of Q. However, the temperature depend...

We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almos...

In the present paper the heat exchange performance of a counter flow double-tube condenser for a ternary refrigerant mixture R407C, composed ofHFC32/HFC125/HFC134a, is calculated using a prediction method developed by the present authors. The axial distributions of vapor and liquid bulk mass fraction, temperature, heat flux, mass flux, etc., are obtained for both a smooth tube and a microfin tu...

the present paper describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. the design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is modelled within the known design variables. mor...