防爆柴油机排气歧管烟气模型的流场分析与优化

Flow Field Analysis and Optimization of Exhaust Manifold Gas Model in Explosion-proof Diesel Engine

利用GT-Power软件对包含进排气歧管的防爆柴油机进行整体性能模拟,得到其排气歧管瞬态工况的质量流量、静压力、温度等参数;在FLUENT软件中对4种瞬态工况的流线、温度场、压力场、速度场等做分析,发现歧管在出口拐角处流动不畅,流线在歧管外侧过于集中,造成大范围低速度涡流;提出了一种改进方案,使得改进后的模型在一定范围内压力降和温度差降低。

By using GT-Power to proceed a performance simulation of the explosion-proof diesel engine including the intake and exhaust manifold, the transient mass flow rate, static pressure and temperature data was got. The flow field analysis in temperature, pressure, velocity of four kinds of transient operating conditions were conducted through FLUENT, founding that the common problems are the flow in export comer is not smooth enough and streamlines concentrate on the outside of manifold, which would cause a large amount of the eddy current in low speeds. The improvement schemes were proposed, w difference within a certain hich indicate the improved model has lower pressure drop and temperature scope.