舰船柴油机微通道内燃油空化现象的模型对比

doi:10.12382/bgxb.2022.0498

摘要/Abstract

摘要：

喷油器是舰船柴油机的关键部件,喷油器喷孔、控制腔进出油孔直径一般在 0.2~0.5mm 之间,属于典型的微通道结构。高压喷射时通道内发生的空化现象,严重影响柴油机的可靠性。湍流和空化模型的选择是使用数值计算方法研究上述空化问题的关键。基于Winklhofer微通道燃油试验,使用代表性较强的3种湍流模型和2种空化模型构建微通道模型,将仿真与试验结果对比分析。研究结果表明:重整化群(RNG) k-ε+Zwart-Gerber-Belamri(ZGB)模型、RNG k-ε+Schnerr-Sauer(SS)模型这两种组合所得的压力梯度值与试验数据相近,误差在7%以下;不同模型组合计算得到的空化分布存在差异;在19~85bar压差范围内,Realizable k-ε+ZGB模型、RNG k-ε+ZGB模型所得出口质量流量与试验数据的变化趋势吻合,且误差不到4%;截面流速计算方面,RNG k-ε+SS模型的计算误差最小,误差处于10%以下。

关键词: 舰船柴油机, 喷油器, 空化, 微通道, 模型对比

Abstract:

The fuel injector is the key component of the marine diesel engine, and the diameters of the injector nozzle and the control chamber oil inlet and outlet, which are typical microchannel structures, are generally between 0.2 and 0.5mm. During high pressure injection, the cavitation phenomenon in the channel seriously affects the reliability of diesel engine. The choice of turbulence and cavitation models is the key to study the above cavitation problems using the numerical calculation methods. Based on the Winklhofer microchannel fuel test, three representative turbulence models and two cavitation models were used to construct the microchannel model, and the simulated results were compared and analyzed with the test results. The results show that the pressure gradient values obtained from the two combinations of RNG k-ε+ZGB models and RNG k-ε+SS models are similar to the experimental data with an error of less than 7%; the cavitation distributions calculated by the different model combinations are different; the outlet mass flow rates obtained from Realizable k-ε+ZGB models and RNG k-ε+ZGB models are consistent with the experimental; in the range of pressure difference from 19 bar to 85 bar, and the outlet mass flow rate obtained from the Realizable k-ε+ZGB model and the RNG k-ε+ZGB model matches the trends of the experimental data, and the error is less than 4%. In the caculation of cross-sectional flow rate, the calculated error of RNG k-ε+SS model is minimum with the error of less than 10%.

Key words: marine diesel engine, fuel injector, cavitation, microchannel, model comparison

中图分类号:

TK421

李子铭, 刘振明, 刘景斌, 陈萍. 舰船柴油机微通道内燃油空化现象的模型对比[J]. 兵工学报, 2023, 44(10): 3091-3100.

LI Ziming, LIU Zhenming, LIU Jingbin, CHEN Ping. Model Comparison of Fuel Cavitation Phenomena in Microchannels of Marine Diesel Engines[J]. Acta Armamentarii, 2023, 44(10): 3091-3100.

图/表 15

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热物性参数	数值
液相密度/(kg·m^-3)	830
液相动力黏度/(kg·m^-1·s^-1)	0.0024
饱和蒸气压/Pa	2000
气相密度/(kg·m^-3)	0.029
气相动力黏度/(10^-6kg·m^-1·s^-1)	3.1×10^-6

热物性参数	数值
液相密度/(kg·m^-3)	830
液相动力黏度/(kg·m^-1·s^-1)	0.0024
饱和蒸气压/Pa	2000
气相密度/(kg·m^-3)	0.029
气相动力黏度/(10^-6kg·m^-1·s^-1)	3.1×10^-6

试验和模型	区段/mm
试验和模型	-1.00~ -0.25	-0.25~ 0.22	0.22~ 0.50	0.50~ 2.00
Winklhofer等^[4-5]试验	95.51	63.68	37.00	28.33
SST k-ω+ZGB模型	97.94	62.26	31.40	33.60
SST k-ω+SS模型	97.29	64.00	32.23	29.21
Realizable k-ε+ZGB模型	97.54	64.18	32.77	32.44
Realizable k-ε+SS模型	97.67	64.99	33.00	28.96
RNG k-ε+ZGB模型	97.78	66.33	34.90	29.31
RNG k-ε+SS模型	97.74	67.98	36.73	29.61

试验和模型	区段/mm
试验和模型	-1.00~ -0.25	-0.25~ 0.22	0.22~ 0.50	0.50~ 2.00
Winklhofer等^[4-5]试验	95.51	63.68	37.00	28.33
SST k-ω+ZGB模型	97.94	62.26	31.40	33.60
SST k-ω+SS模型	97.29	64.00	32.23	29.21
Realizable k-ε+ZGB模型	97.54	64.18	32.77	32.44
Realizable k-ε+SS模型	97.67	64.99	33.00	28.96
RNG k-ε+ZGB模型	97.78	66.33	34.90	29.31
RNG k-ε+SS模型	97.74	67.98	36.73	29.61

试验和模型	区段/bar
试验和模型	19~70	70~85
Winklhofer等^[4-5]试验	6.89	7.78
SST k-ω+ZGB模型	7.10	8.19
SST k-ω+SS模型	7.15	8.43
Realizable k-ε+ZGB模型	6.93	8.03
Realizable k-ε+SS模型	6.96	8.19
RNG k-ε+ZGB模型	6.86	8.03
RNG k-ε+SS模型	6.93	8.15