100吨级核热火箭发动机喷管流动传热特性数值分析

Numerical Analysis of Flow and Heat Transfer Characteristics of 100 Ton Nuclear Thermal Rocket Engine Nozzle

为了阐明核热火箭发动机喷管内氢的流动传热特性,根据100吨级核热火箭发动机喷管设计参数,建立了喷管再生冷却传热模型与可压缩膨胀模型,采用Fluent软件数值模拟了喷管的流动传热行为。结果表明,当喷管面积比从100增加到300时,发动机比冲的增幅逐渐减小;在冷却通道高度从0.012 m增加到0.024 m的过程中,通道压降逐渐降低,冷却气体温升变化不大。此外,氢的离解会影响喷管内介质的流动传热,离解的氢在喷管内重组为氢气释放的热量参与管内传热与做功,使喷管收敛段内壁面热流密度增加,出口比冲升高。

the nuclear rocket engine,the regenerative cooling and heat transfer model and compressible expansion model were established according to the nozzle design parameters of 100-ton nuclear thermal rocket engine.The software of Fluent was used to simulate the flow and heat transfer process of the nozzle.The results showed that as the nozzle area ratio increased from 100 to 300,the increase in specific impulse was gradually decreasing.When the cooling channel height increased from 0.012m to 0.024m,the channel pressure drop decreased and the temperature rise of the cooling gas did not change much.In addition,the hydrogen dissociation affected the flow and heat transfer of the medium in the nozzle.The dissociated hydrogen was recombined in the nozzle and released heat participated the heat transfer and worked in the nozzle,which increased the heat flux density on the inner wall of the converging section and raised the outlet specific impulse.