3-D NUMERICAL INVESTIGATION AND OPTIMIZATION OF CENTRIFUGAL SLURRY PUMP USING COMPUTATIONAL FLUID DYNAMICS

Enerji dönüşüm uygulamaları, kullanılan türbomakinaların ve verimlerinden direk olarak etkilenmektedir. Enerjinin önemi ve türbomakinaların geniş uygulama alanı, türbomakinaların bileşenlerinin optimizasyonunu çok önemli kılar. Optimizasyon için, gerçek akış alanı ve türbomakina bileşenleri arasındaki etkileşim 3 boyutlu çalışmalar olarak ortaya konması gerekir. Birçok çalışma su pompalarının bileşenleri olan salyangoz ve çark optimizasyonuna odaklanmasına rağmen, santrifüj çamur pompaları için aynı sistematik metodoloji ve çalışma mevcut değildir. Bu çalışmanın amacı Hesaplamalı Akışkanlar Dinamiği (HAD) vasıtasıyla santrifüj çamur pompasının performansını iyileştirmektir. Bu nedenle, kapalı tip çarkın optimizasyonu için kanat çıkış açısı, ara kanatçık eklenmesi ve kanadın modifiye edilmesi göz önünde bulundurularak kapsamlı bir parametrik çalışma yürütülmüştür. İlave olarak, orijinal pompanın salyangoz dil bölgesi tekrar tasarlandı. Bu çalışmadan elde edilen sonuçlar göstermiştir ki doğru parametrelerin seçilmesiyle santrifüj çamur pompası çarkı ve salyangozunun performanslarının artırılması mümkündür. Sayısal olarak elde edilen analiz sonuçlarına göre, çamur pompasının hidrolik verimi geriye eğimli uzun kanatlı çark ve ilk duruma göre modifiye edilmiş salyangozun kullanılmasıyla % 9'a kadar artırılabilir. Çalışmanın son bölümü bir durum çalışması olarak temiz su ile karşılaştırıldığında farklı konsantrasyonlarda çamur karışımı iletilirrken çamur pompasının performansı üzerinde duruluyor. Akış şekli anlık basınç konturları ve hız akım çizgileri ile görselleştirilmiştir. Dahası her bir pompanın karekteristik performans eğrileri karşılaştırıldı ve tartışıldı. Ayrıklaştırılmış, üç boyutlu, sıkıştırılamaz Navier-Stokes denklemlerinin sayısal çözümleri yapılandırılmış ağ kullanılarak ticari yazılım Fluent ile gerçekleştirilmiştir.

HESAPLAMALI AKIŞKANLAR DİNAMİĞİ (HAD) KULLANILARAK ÜÇ BOYUTLU SANTRİFÜJ ÇAMUR POMPASININ SAYISAL OLARAK İNCELENMESİ VE OPTİMİZASYONU

Energy conversion applications are directly affected through the employment of turbomachines and their efficiencies. Energy importance and wide-spread application of turbomachines, make it crucial to optimize their components. In order to optimizastion, the actual flow field and the interaction between the components must be revealed as 3-D studies. Although many studies have focused on the component optimization, mainly volute and impeller in water pumps, there is no systematic elaboration of the same methodology for centrifugal slurry pumps. The purpose of this paper is to improve the performance of a centrifugal slurry pump by means of Computational Fluid Dynamics (CFD). Therefore, an extensive parametric study has been carried out in order to optimize the shroud type impeller taking into account the blade discharge angle ((backward long blades). Additionally, the tongue region of the original pump is re-designed. The results obtained in this study show that it is possible to improve the performance of the impeller and the volute of the centrifugal slurry pump by choosing correct parameters. From the analysis point of view, it is demonstrated numerically that the hydraulic efficiency of the centrifugal slurry pump can be increased up to 9% by using the backward long blades in addition to modified volute compared to the original ones. The last stage of the study focuses on the performance of slurry pump while handling slurry mixture at different concentrations in comparison with clear water as a case study. The flow pattern is visualized with the instantaneous pressure contours and the velocity streamlines. Furthermore, the characteristic performance curves of each pump are compared and discussed. The numerical solutions of the discredited three-dimensional, incompressible Navier-Stokes equations over the structured mesh are accomplished with commercial software Fluent®.

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