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سلام دوستان عزیز دانلود یک جزوه بسیار عالی از شرکت فن اوران پتروشیمی درزمینه اشنایی با پمپ ها واموزش مطالب مرتبط با پمپ مبانی پمپها مقدمه ای برپمپاژ وانواع پمپ تئوری عملکرد پمپ های گریز از مرکز دسته بندی پمپ های گریز از مرکز پروانه ها یا Impellers سرعت مخصوص وکاربردهای ان تاثیرخواص فیزیکی مایع مورد پمپاژ برعملکرد پمپ های گریز از مرکز کاویتاسیون Cavitation دانلود
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- cavitation
- impellers
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Cavitation is one of major problems facing pump and inducer designers. Cavitation occurs in liquids when the local pressure is reduced to the vapor pressure of the liquid. Water, one of the most common working fluids, has a high propensity to cavitate under common operating conditions. Pumps and inducers are often damaged by the collapsing micro-bubbles that are formed by the cavitation process and efficiency can deteriorate severely. ANSYS CFX software includes a state-of-the-art cavitation model based on a volume-of-fluid (VOF) approach [1]. This robust model allows the prediction of the cavitation size and location, very accurately. The animation, below, shows the evolution of the vapor pocket and the corresponding head drop curve at design point for the SHF pump . Figure 1: Cavitation evolution and corresponding drop curve for the SHP centrifugal pump. Usually, an inducer is placed upstream of a pump to resist the cavitation. For this purpose, an inducer has a small number of blades (generally 3 blades) with long chords and a very high stagger angle. This particular design makes simulating the flow field through this type of rotating machinery very challenging even without cavitation modeling. Using the VOF model, the flow field has been predicted at design and off design regimes under cavitating conditions [2 References [1] Bakir, F., Rey, R., Gerber, A. G., Belamri, T. and Hutchinson, B., “ Numerical and experimental investigations of the cavitating behaviour of an inducer”, International Journal of Rotating Machinery, 10:15-25,2004. [2] Zwart, P., Belamri, T. and Gerber, A. G., “ A Two-Phase Model for Predicting Cavitation Dynamics”, ICMF 2004, Yokohama, Japan, May 30-June 3, 2004. Paper No.152.
