中文摘要：

针对高原地区火羽流中心线的温升特性,在3个小尺寸火源试验结果的基础上,将火源功率进行无量纲化,运用CFD模拟软件进行了大规模的数值模拟并对模拟结果进行了分析。通过将模拟结果与两大经典羽流模型Heskestad和McCaffrey预测模型进行比较,分析了这两大模型在高原地区低压低氧环境下的适用性,并对后者在海拔4 000 m高原处进行了修正,以满足其在高原地区的适用性。

英文摘要：

This paper, based on the results of three small scale experiments done in the Tibet region, China, is aimed to simulate the full-scale axi-symmetric fire plumes under different plateau conditions for the dimensionless fire power by means of computational fluid dynamics software so as to solve numerically the form of the Navier-Stokes equations appropriate for low speed, thermally driven flow with the stress on smoke and heat transfer from the fires. In our paper, we have made a comparison of the experimental and the simulated results in Tibet area with calculated ones of Heskestad＇s and Mccaffrey＇s plume prediction model, and then analyzed the applicability of these classical models in the plateau conditions. Thus, the first conclusion we have arrived at is that the centerline plume temperature tends to increase with the increase of the elevation, whereas the second conclusion we have made is that the calculation result of the Heskestad＇s plume model which had taken into account the differences between the fire plume density and the ambient air density, tends to be higher than the simulated one, with the discrepancies increased with the increase of the dimensionless fire power or the decrease with the outside pressure and air density. Then, the calculation results of the Mccaffrey＇s plume model prove to be lower than the simulated one. In addition, at the high altitudes, the decreasing rate of the centerline plume temperature tends to rise with the height predicted by the Mccaffrey＇s plume model slower than the simulation results. But both of them have made a perfect prediction for the small scale fire power in which the amount of ambient air was very little entrained. In this connection, we have also analyzed the centerline plume temperature decreasing trend at the altitude of 4 000 meters high and then amended the Mccaffrey＇s plume model appropriately in accordance with the results of our own experiments with the parameters of η=-3/4, k=0.69 in the plume region on this plateau, which can serve as s