高原山地环境腹箱式灭火飞机投水数值模拟

Numerical simulation of water-dropping process by fire-fighting airtanker in plateau mountain

为探究高原山地环境下腹箱式灭火飞机投水着水特性,基于VOF多相流模型构建了飞机投水过程仿真模型,分析地形坡度和海拔高度对地面落水分布的影响,并以投水有效利用率和有效水体覆盖厚度为指标评估其投水效能.结果表明,随山地坡度增加,相同飞行速度下落水地面分布的长度减小而宽度增加,落水区域前端水体分布更密集;随海拔高度增加,相同飞行速度下地面落水分布中后区域更连续,且高原环境下落水地面分布宽度增加但长度变化较小.此外,投水效能普遍随坡度的增加先降低后提高;投水有效利用率在小坡度时随海拔高度增加而提高,其他工况下受海拔高度影响较小,有效水体覆盖厚度普遍随海拔高度增加而降低.

To study the water touching characteristics of fire-fighting airtanker in plateau mountain,the numerical simulation model based on VOF multiphase flow model was employed to simulate the water-dropping process,the effects of terrain slope and altitude on precipitation area were analyzed,and the effective water delivery utilization rate and effective water coverage thickness were selected to evaluate firefighting efficiency.The results showed that with the increase of mountain slope,the length of the precipitation area of the same flight speed was decreased and the width was increased,the front of the precipitation area was more dense.With the increase of altitude,the middle and back areas of the covered area were more continuous at the same flight speed and the width was increased as the length varying slightly.Moreover,the firefighting efficiency generally decreased and then increased with the increase of slope,the effective water delivery utilization rate increased with the increase of altitude at small slope,and in other working conditions was less affected by the altitude,the effective water coverage thickness generally decreased with the increase of altitude.