Papers by Keyword: Wall Temperature

Abstract: Conservation equations of mass, momentum and energy have been solved using Fluent 14 to compute the Nusselt number and wall temperature of a finned rectangular Micro-channel for a laminar flow for water and nanofluids under mixed flow condition. Alumina based water is considered as nano fluid for the present investigation. It has been found from the numerical investigation that as the percentage of alumina is increased in the base fluid (water) the heat transfer rate is increased. It has been found that the wall temperature decreases with increase in fin number. The heat transfer is found to be more in rectangular shaped fin compared to any other shape both for the water and nanofluid. In addition to thermal characteristics, the variation of pressure drop for different fin number has also been investigated.

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This paper introduces the structure and working principle of biomass fuel hot stove, and analyses the existing problems in the combustion process. Simultaneously, the paper proposes the optimization about the wall high temperature of the hot stove, which is the main issue in the hot stove.

Biomass resources in China is very abundant.only the amount of resources of agricultural wastes (such as straw) each year is equivalent to 3.08 tons of standard coal. The biomass briquette is compressed with loose, amorphous materials, such as straw, rice husk, sawdust, wood chips, into a shaped, denser solid fuel with the method of mechanical pressure. It has the advantages of small size, high density, easy storage and transportation, combustion stability, long cycle, high combustion efficiency, low contaminant levels in ash and flue gas. It provides an effective way to solve the energy shortage in rural areas and straw burning problem fundamentally[1].

Abstract: A calculation method for cooling load of stratified air conditioning system based on the simultaneously solving model is presented. Thermal environment experiment under summer condition is carried out in a large space building, indoor air temperature, inner wall surface temperature and cooling capacity were obtained; the stratified air conditioning cooling load calculated by the simultaneously solving model is compared with air conditioning cooling capacity in experiment, the relative error is 14%, taking the loss of cooling capacity and leakage loss, it can be thought that the simultaneously solving model can be used to calculate cooling load of stratified air conditioning system.

Abstract: Missile airframe experiences large variations in wall temperature along the circumference due to high angle of attack, especially at hypersonic speeds, which leads to large thermal stresses and bending loads. Such a situation with large wall temperature variations occurs due to high angle of attack during flight. Thermal design of the airframe involves the estimation of local flow parameters and heat flux distribution. Kinetic heating analysis has been carried out for the prediction of heat load distribution on missile airframe considering hypersonic flow with high angle of attack for a particular flight trajectory. Out of a set of possible flight trajectories, a trajectory producing minimum circumferential variation in wall temperature, as concluded through kinetic heating analysis, is finalized. Transient three dimensional heat transfer analysis of the airframe is carried out for prediction of wall temperature distribution for proper selection of material of construction of airframe so that it retains its strength at elevated temperatures. Parametric study has been carried out considering various combinations of airframe wall thickness in presence of external thermal protection coating and internal insulation for the finalized trajectory. Based on the present analysis, airframe configuration having axially variable wall thickness corresponding to the selected flight trajectory is finalized. The validation of the methodology adopted for the analysis has been carried out with respect to airframe temperature data acquired during flight.

Abstract: As the critical component of the system, micro-combustor requires a high and uniform temperature distribution along the wall to meet demands for the band gap of the PV cells. The past experiments have proved that the peak wall temperature of the combustor with porous media increases obviously. This paper will have a research on stratified porous media to enhance the combustion efficiency of the combustor and reduce the emissions.

Abstract: This research is concerned with the experimental study of the wall temperature behavior of salt powders in the spray-drying process under various inlet temperatures. The results are presented and discussed in terms of the temperature profiles within two sections of the drying chamber that consists of cylindrical and conical sections. Firstly, the temperature profiles of cylindrical section have shown that the behavior from the steps of spraying air, water, and solution before has lead to a steady state process. Finally, the wall temperature distribution at each elevation has shown a statistically significant difference. In our future work, the wall temperature behavior will be compared with the wall deposition flux in order to determine a prediction equation that can be applied to manage the deposition problem in the spray-drying process stage.

Abstract: In this paper, the boiling heat transfer test rig was designed and built, while the characteristics of boiling Heat Transfer of refrigerants in micro-channel was researched. The wall temperature of micro-channel was measured by TH5104 Infrared thermography. The results showed that there were obvious variations for wall temperature of micro-channel along the axial direction when boiling heat transfer occurred in the micro-channel. The temperature distribution affected obviously by the heat flux, mass flow rate; vapor quality and heat transfer model.