Influence of rotor diameter‑distance ratio on performance of fuel cell gas circulating pump
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摘要:
为了揭示径距比对凸轮式气体循环泵的气动性能的影响规律,通过坐标变换推导了3叶的圆弧⁃渐开线⁃圆弧转子型线方程,建立6种不同径距比的气体循环泵模型进行对比分析。采用重整化
k⁃ε (RNGk⁃ε )湍流模型对转子腔内部进行三维非定常数值计算,结合动网格技术分析转子径距比对气体循环泵流量特性、转子腔速度分布的影响规律,并与试验结果进行对比。结果表明:转子径距比对气体循环泵性能影响较为明显,随着转子径距比由1.34增大到1.45,泵出口平均流量与瞬时流量脉动呈上升趋势,且在1.38~1.40时变化较为明显,平均流量增大了0.001 833 m3/s(15.8%);转子径距比在1.38~1.40时,转子受力较好,对转子径向激励力分量Fx 的抑制较为明显,对转子径向激励力分量Fy 的影响不显著;随径距比变化,转子腔内涡量分布变化较为明显,转子径距比在1.40时,转子腔内涡量分布较小,有效抑制了气体回流。Abstract:In order to reveal the influence of the diameter⁃distance ratio on the aerodynamic performance of the cam⁃type gas circulating pump,a three⁃lobe arc⁃involute⁃arc rotor profile equation was derived through coordinate transformation,and 6 gas circulations with different diameter ratios were established to compare and analyze the pump model.The re⁃normalization group
k⁃ε (RNGk⁃ε ) turbulence model was used to calculate the three⁃dimensional unsteady numerical simulation inside the rotor cavity,and in combination with the dynamic grid technology,the influence of the rotor diameter ratio on the volume flow characteristics of the gas circulating pump and the velocity distribution of the rotor cavity was analyzed,and the results were compared with the experimental results.The results showed that the rotor diameter‑distance ratio had a significant influence on the performance of the gas circulating pump.As the rotor diameter⁃distance ratio increased from 1.34 to 1.45,the average volume flow and instantaneous volume flow pulsation at the outlet of the pump showed an upward trend,and the changes were more obvious between 1.38-1.40.The average volume flow increased by 0.001 833 m3/s (15.8%);when the rotor diameter⁃distance ratio was 1.38-1.40,the rotor received better force,the suppression of the radial excitation force componentFx of the rotor was more obvious,and the influence on the rotor radial excitation force componentFy was not significant;the vorticity distribution in the rotor cavity changed significantly with the variation of the diameter⁃distance ratio.When the rotor diameter⁃distance ratio was 1.40,the vorticity distribution in the rotor cavity was smaller,which effectively suppressed gas backflow. -
表 1 径距比参数
Table 1. Diameter⁃distance ratio parameters
κ D/mm A/mm 1.34 90 67 1.36 90 66 1.38 90 65 1.40 90 64 1.43 90 63 1.45 90 62 -
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