| 摘要:针对匹配3 000 ～5 000 kW船用柴油机的单级最高压比为6的涡轮增压器压气机，采用CFD模拟其稳态与瞬态过程的流动，包括速度、温度和压力的变化，以及流动分离、马赫数分布、流动稳定性等。结果表明，压气机在稳态工况效率随压比呈“单峰型”分布，流动平稳，无明显分离，马赫数从压气机入口0.9平稳降至出口0.4。在过渡时间为0.01 s的压气机急减速与过渡时间为0.10 s的缓减速瞬态工况，流体惯性与转速变化速率的耦合主导压气机效率衰减与出口压力波动等。在急减速时，压气机效率下降5.78%，出口压力波动较缓减速时高12%。在缓减速时，效率仅下降2.42%，流场随时间变化平缓。与稳态相比，瞬态的压气机动叶内流体最高速度下降6.67%，扩压器内平均速度降低超5%。 |
| 关键词: 船用柴油机 涡轮增压器 瞬态流动 压气机效率 |
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| Steady-State and Transient Flow of the Compressor of a Marine High-Pressure-Ratio Turbocharger |
| Wu Qingxian,Qiao Xinqi,Yan Chao,Zhao Xinyu,Wang Xiaoli |
| 1Shanghai Jiao Tong University， Shanghai 200240， China;2Kangyue Technology （Shandong） Co.， Ltd.， Shouguang 262711， China |
| Abstract:For the single-stage turbocharger compressor with a maximum pressure ratio of 6，matched to marine diesel engines ranging from 3 000 kW to 5 000 kW，CFD simulation on its steady-state and transient flow processes is conducted，including changes in velocity，temperature，and pressure，as well as flow separation，Mach number distribution and flow stability.The results show that under steady-state conditions，the compressor efficiency follows a unimodal distribution with the pressure ratio，the flow is stable without obvious separation，and the Mach number decreases steadily from 0.9 at the compressor inlet to 0.4 at the outlet.Under transient conditions of rapid deceleration with a transition time of 0.01 s and slow deceleration with a transition time of 0.10 s，the coupling of fluid inertia and rotational speed change rate dominates the decay of compressor efficiency and outlet pressure fluctuation.During rapid deceleration， the compressor efficiency decreases by 5.78%，and the outlet pressure fluctuation is 12% higher than that during slow deceleration.During slow deceleration，the efficiency only decreases by 2.42%，and the flow field changes gently over time.Compared with the steady state，the maximum fluid velocity in the compressor rotor blades decreases by 6.67% in the transient state，and the average velocity in the diffuser decreases by more than 5%. |
| Key words: marine diesel engine turbocharger transient flow compressor efficiency |
