Thermodynamic efficiency of the compression process in oil-flooded screw compressors depends greatly on the oil-gas heat transfer process. The amount of heat transfer is a function of many parameters such as mode of oil injection, oil inlet temperature, etc. This paper describes a mathematical model to calculate this heat transfer, assuming that the oil is injected in the form of non-interactin...

In this paper, the conjugate gradient method coupled with adjoint problem is used in order to solve the inverse heat conduction problem and estimation of the strength of the time- dependent heat source using the temperature distribution at a point in a three layer system. Also, the effect of noisy data on final solution is studied. The numerical solution of the governing equations is obtained b...

The thermal influence of carbon nanotubes (CNTs) on the PA12 in the laser sintering process was assessed by physical experiments and a three dimensional simulation model. It appears that, by adding the CNTs into the PA12 matrix, the thermal conductivity increased. A double ellipsoidal heat flux model was applied to input a three dimensional, continuous moving, volumetric laser heat source. The ...

Original scientific paper In a submerged arc welding process, the concept of temperature distribution is essential in order to control the HAZ (heat-affected zone) dimensions and get the required bead size and quality. In this paper, an analytical solution for moving heat source with Gaussian distribution of inside volume of central conicoidal shape is derived. Heat transfer in welded plates du...

Temperature boosting of waste heat from spacecraft by means of heat pumps makes it possible, under some conditions, to achieve considerable savings in radiator area and mass. This study considers several possibilities for employing workactuated and heat-actuated heat pumps (WAHP and HAHP, respectively) for this purpose. In the former case, the spacecraft power source is required to generate ext...

The traditional cutting of fiber-reinforced plastics causes serious concern of tool wear. The merits of narrow cuts and flexible path of lasers lead to the application of the shaping operation of composite material after curing. However, laser-induced thermal damage is often produced. It leads to poor assembly tolerance and long-term performance deterioration. The current study derives the conc...

mixed convection fluid flow and heat transfer of water-al2o3 nanofluid inside a lid-driven square cavity has been examined numerically in order to find the optimal distribution of discrete heat sources on the wall of a cavity. the effects of different heat source length, richardson number and grashof number on optimal heat source location has been investigated. moreover, the average nusselt num...