单向多孔材料在电弧中冷却性能的数值模拟

Numerical Study on the Cooling Performance of directional Porous Materials in Electric Arcs

定向凝固制备的单向多孔材料在电弧加热器中可以替代水冷铜壁,提高电弧加热器的焓值和热效率,具有广阔的应用前景。针对单向多孔材料在电弧中的传热过程建立数学模型,利用数值模拟的方法研究了孔隙率、孔直径、通入角和注入率对单向多孔材料在电弧中冷却性能的影响规律。结果表明:孔隙率从7.9%增加到26.7%时,内壁面的热通量可降低约92%;在孔隙率和冷气流速不变的条件下,孔直径从0.3 mm增加到0.8 mm时,内壁面的平均温度从498 K增加到697 K;通入角的变化会同时影响单向多孔材料内壁面热通量和冷气注入率,进而影响材料的冷却性能;冷态气流注入率从14.2%增加到42.7%时,单向多孔材料内壁面热通量降低约17%。本研究结果可为单向多孔材料在电弧加热器中的应用提供参考。

Directionally solidified porous materials could be used to replace the water-cooled cooper walls in arc heaters,by which the enthalpy of the gas flow and the heat efficiency could be improved,and thus has a wide application prospect.In this paper,a mathematical model is developed for the heat transfer in unidirectional porous materials contacted with electric arcs.Numerical simulations are carried out to study the effects of porosity,aperture diameter,entry angle,and injection rate on the cooling performance of directional porous materials.The results indicate that the heat flux of the inner wall decreases by 92%with the increase in the porosity from 7.9%to 26.7%.When the porosity and flow velocity are constant,the average temperature of the inner wall increases from 498 K to 697 K with the increase in the aperture diameter from 0.3 mm to 0.8 mm.The variation of the entry angle could affect the injection rate and heat flux of the inner wall,and then change the cooling performance of the directional porous material.In addition,the increase in the injection rate from 14.2%to 42.7%could decrease the heat flux of the inner wall by approximately 17%.The results provide a reference for the application of unidirectional porous materials in arc heaters.