the subjects of heat transfer and cooling system are very important topics in the internal combustion engines (ice). in modern cooling systems, low weight, small size and high compactness are the critical designing criteria that requires heat transfer enhancement. boiling phenomenon which is occurred in the water jacket of the ice is one of the methods to increase heat transfer in the coolant s...

Fouling is a common, fundamental and costly problem in heat transfer systems, which reduces thermal efficiency of equipment, increases the energy loss and causes strong damage to the heat transfer equipment in various industries. The main causes of fouling on the heat transfer surfaces are salts with inverse temperature-solubility in the fluid which calcium sulfate is one of the most important ...

in this paper, free convection in an inclined stepped chamber has been studied. one wall of this enclosure is kept cold and the opposite wall equipped with constant heat source. the remaining walls are maintained adiabatic. there is one adiabatic step on the bottom wall. the aim of the present study is to forecast the effect of raleigh number, slope of enclosure, step dimension, and heat source...

in this research the simulation of an air independent proton exchange membrane fuel cell (pemfc) propulsion system was taken into consideration. the system consists of several parts including pem fuel cell stack, metal hydride and liquid oxygen (lox) tanks, and also pre-heaters of oxygen and hydrogen gases along with other heat exchangers, to ensure proper operation of system. the heat recovery...

introduction nowadays, due to higher environmental pollution and decreasing fossil fuels many countries make decisions to use renewable fuels and restrict using of fossil fuels. renewable fuels generally produce from biological sources. biodiesel is an alternative diesel fuel derived from the transesterification of vegetable oils, animal fats, or waste frying oils. considering the differences be...

this paper presents a simple methodology for cost estimation of a near optimal heat exchanger network, which comprises mixed materials of construction. intraditional pinch technology and mathematical programming it is usually assumed that all heat exchangers in a network obey a single cost model. this implies that all heat exchangers  in a network are of the same type and use the same materials...

fatigue behavior of a vanadium microalloy steel has been studied in this research. here, microstructure constituents were considered which essentially are dependent on the heat treatment conditions. the results of high cycle fatigue tests revealed that heat treatment procedure and cooling rates have significant effects on fatigue properties. optimal heat treatment cycle of the microalloyed stee...

conceptual design of a waste heat recovery cycle is carried out in attempt to enhance the thermal efficiency of a steam power plant. in the recovery system, super-critical an co2 is employed as the working fluid operating in a brayton cycle. low grade heat rejected by the flue gases through the stack is used as the primary heat source, while a secondary heat exchanger utilizes the hot gases lea...

Most of internal combustion engines have one or two heat shields that have been installed on the exhaust manifold to avoid the heat transfer to upper parts of the engine such as the valve cover. In some engines, this part fails due to the fracture and causes engine noise and other failures in the engine. In this paper, the failure of a heat shield due to vibrational loads of the engine has been...

treatment of human promonocytic leukemic cell line u937 with mild hyperthermia in the temperature range of 40-43°c resulted in differentiation of these cells into monocyte/macrophage-like cells in a heat dose and time dependent manner. this process was accompanied by marked morphological, functional and proliferational changes. u937 cells which normally grow in supension in the logarithmic phas...