Theoretical and experimental study has been performed on heat transfer of airwater two phase laminar annular flow through a uniformly heated vertical small tube. Analysis ascertains that the mechanism of heat transfer...Theoretical and experimental study has been performed on heat transfer of airwater two phase laminar annular flow through a uniformly heated vertical small tube. Analysis ascertains that the mechanism of heat transfer is the evaporation of a very thin liquid film attached on the tube wall. The predictions of analytical solutions are quite good compared with the experimental results.展开更多
This article deals with the effects of a blowing ratio measured with narrowband liquid crystal in transonic experiments on the heat transfer characteristics of trailing edge cutback. The experimental results are compa...This article deals with the effects of a blowing ratio measured with narrowband liquid crystal in transonic experiments on the heat transfer characteristics of trailing edge cutback. The experimental results are compared and contrasted in terms of available data for traditional experiments with thermocouples. It is concluded that the blowing ratio exerts rather significant effects on film cooling effectiveness distribution of the rib center line. As the blowing ratio decreases, similar to the cooling effectiveness distribution curve of the slot center line, that of the rib center line makes a clockwise rotation about the end. When the blowing ratio increases, the regular film cooling effectiveness curve of the surface becomes rather smooth. On the whole measuring surface, the most intensive heat transfer occurs at the extended borderline of the slot and the rib, neither at the rib center line nor at the slot center line. The experimental results of cooling effectiveness measured with thermocouples are lower than those with liquid crystal. In addition, the transient experiments using narrowband liquid crystal can eliminate the higher errors of Nusselt numbers in measurements with thermocouples at the slot outlet.展开更多
The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turb...The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turbulent model,both heat conduction and turbulent heat transfer of liquid film at high speed of gas determine the condensation heat transfer of mixture gas.Condensation heat transfer coefficient could be predicted by Re and Co of liquid film.The correlation of condensation heat transfer coefficient was established.展开更多
文摘Theoretical and experimental study has been performed on heat transfer of airwater two phase laminar annular flow through a uniformly heated vertical small tube. Analysis ascertains that the mechanism of heat transfer is the evaporation of a very thin liquid film attached on the tube wall. The predictions of analytical solutions are quite good compared with the experimental results.
文摘This article deals with the effects of a blowing ratio measured with narrowband liquid crystal in transonic experiments on the heat transfer characteristics of trailing edge cutback. The experimental results are compared and contrasted in terms of available data for traditional experiments with thermocouples. It is concluded that the blowing ratio exerts rather significant effects on film cooling effectiveness distribution of the rib center line. As the blowing ratio decreases, similar to the cooling effectiveness distribution curve of the slot center line, that of the rib center line makes a clockwise rotation about the end. When the blowing ratio increases, the regular film cooling effectiveness curve of the surface becomes rather smooth. On the whole measuring surface, the most intensive heat transfer occurs at the extended borderline of the slot and the rib, neither at the rib center line nor at the slot center line. The experimental results of cooling effectiveness measured with thermocouples are lower than those with liquid crystal. In addition, the transient experiments using narrowband liquid crystal can eliminate the higher errors of Nusselt numbers in measurements with thermocouples at the slot outlet.
文摘The condensation heat transfer and pressure drop investigation of kerosene-air mixture gas (the range of noncondensable gas mass quantity is 5%-52%) in horizontal tube was carried out.According to the liquid film turbulent model,both heat conduction and turbulent heat transfer of liquid film at high speed of gas determine the condensation heat transfer of mixture gas.Condensation heat transfer coefficient could be predicted by Re and Co of liquid film.The correlation of condensation heat transfer coefficient was established.
