喷嘴导流片对喷水推进泵性能的影响

Influence among nozzle guide vanes on the performance of a water-jet pump

本文提出减少径向高度和导流片环绕导流锥分布这2种喷嘴导流片结构,通过DES-FEM耦合的方法研究了喷嘴导流片对喷水推进泵推力及噪声性能的影响。结果表明,随着喷嘴导流片径向高度减少,喷水推进泵推力增大0.61%,流量略微增大而扭矩略微降低,内流噪声主频仍为导叶叶频但幅值降低2.43%,总声压级略微升高;导流片环绕导流锥分布时,喷水推进泵推力提高1.03%,流量增大0.76%,扭矩提高,声压级主频处幅值降低2.05%,总声压级降低,内流噪声主频由导叶偏移至叶轮处,但两者声压级幅值差异较小;各方案频谱中均存在叶轮叶频谐频;内流噪声能量主要集中在中低频段。

Two crucial parameters,namely the radial height and distribution of the nozzle guide vanes,were taken into consideration,based on the initial nozzle guide vane structure.The influence of various nozzle guide vanes on the thrust and noise performance on the water-jet pump was studied by hybrid method of DES and FEM.The numerical results illustrated that as the radial height of the nozzle guide vanes decreases,the thrust and flow rate of the WJP increase while the torque de-creases a little.Besides,the guide vane passing frequency is still identified as the main frequency of internal flow noise,al-though the amplitude of sound pressure level decreases 2.43%.The overall sound pressure level of internal flow noise in-creases.When the nozzle guide vanes are distributed around the guide cone,the thrust of the water-jet pump increases by 1.03%,flow rate increases by 0.76%and toque increases a lttle.Meanwhile,the amplitude at the main frequency of sound pressure level decreases by 2.05%and the overall sound pressure level of internal flow noise decreases.Additionally,the main frequency of internal flow noise shifts to the impeller blade passing frequency and the guide vane passing frequency be-comes the secondary frequency.However,the difference in sound pressure level amplitude between these two frequencies is small.There is impeller blade harmonic frequency in different schemes.Internal flow noise energy is predominantly found within the low to medium frequency band.