Radyal tipteki bir çamur pompası optimizasyonu ve analizi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Pompalarda akı? üç boyutlu, oldukça karı?ık ve yüksek derecede türbülanslıdır. Klasik tasarım metodolojisi bir boyutlu akı? yakla?ımı esasına dayanmaktadır. Bu nedenle Hesaplamalı Akı?kanlar Dinamiği temel tasarımdan sonra çark optimizasyonu için çok önemli bir araçtır. Bu tezde kapalı çarklı radyal ticari bir çamur pompasının HAD yardımıyla optimizasyonu yapılmı?tır. Optimizasyon çalı?ması için kanat sayısı, kanat açısı, salyangoz dili ve ara kanatçık birer parametre olarak belirlenmi?tir. Uzun süren analiz çalı?maları için HAD yazılımı olan Fluent 14 kullanılmı?tır. Optimizasyon çalı?ması sonucu mevcut pompa performansı ilk duruma göre %10 artırılmı?tır. Son olarak ticari çamur pompasının farklı çamurları iletmesi durumunda performansı literatürde bilinen Engin ve Gür korelasyonu ile tahmin edilmi?tir. Anahtar kelimeler: Radyal çamur pompası, Hesaplamalı akı?kanlar dinamiği (HAD), Optimizasyon, Pompa performansı, Kapalı çarkThree dimensional flows in the pumps are quite complicated due to high degree of turbulence. The classical design methodology is basically based on one-dimensional flow approximation. Therefore Computational Fluid Dynamics is a crucial tool to optimize an impeller after basic design. In this thesis, a commercial centrifugal slurry pump with shrouded impeller has been optimized using CFD. The number of blades, blade angles, scroll tongue, and use of secondary blades have been considered as the parameters to be optimized. Fluent 14 has been employed as the CFD code for this long-run study. The optimization results showed that the existing pump efficiency could be improved at least 10%. Furthermore the performance of the commercial slurry pump has been predicted for different kinds of slurries using correlation proposed by Engin and Gur. Keywords: Centrifugal slurry pump, Computational fluid dynamics (CFD), Optimization, Pump performance, Closed type impelle

PARAMETRIC INVESTIGATION OF A CENTRIFUGAL SLURRY PUMP WHILE HANDLING CLEAR WATER

The results show that the increase in blade number leads to an increase at head and shaft power. However, the hydraulic efficiency is variable and depends on flow rates. Around operation conditions of the studied pump, the impellers which have three and four blades are more efficient than impellers with two and five blades. Furthermore, by increasing of blade height from 30 mm to 50 mm, the performance of the slurry pump increases only at high flow rates. On the other hand with the decreases in blade thickness from 50 mm to 30 mm, the performance of centrifugal slurry pump increases at all flow range

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

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 (beta(2)), addition splitter blades and modified blade (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

Computational investigation of heat transfer and pressure drop in a typical louver fin-and-tube heat exchanger for various louver angles and fin pitches

In this study 3-D numerical simulations on heat transfer and pressure drop characteristics for a typical louver fin-and- double-row tube heat exchanger were carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles, fin pitch and Reynolds number, and reported in terms of Colburn j-factor and Fanning friction factor f. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles between 20° ≤Ө≤ 30°, louver pitch of Lp=3.8 mm and frontal velocities of U between 1.22 m/s - 3 m/s. In addition, flow visualization of detailed flow features results, such as velocity vectors, streamlines and temperature counters have been shown to understand heat transfer enhancement mechanism. The present results indicated that louver angle and fin pitch noticeably affected the thermal and hydraulic performance of heat exchanger. It has been seen that increasing louver angle, increases thermal performance while decreasing hydraulic performance associated to pressure drop for fin pitches of 3.2 mm and 2.5 mm. Fin pitch determines the flow behaviour that for fin pitch of 2 mm, increasing louver angle decreased heat transfer and pressure drop. Velocity vectors and streamlines give considerable information about the flow whether it is duct directed or louver directed. For all conditions the flow is louver directed

A review of flow boiling in mini and microchannel for enhanced geometries

WOS: 000432736400010Flow boiling researches in enhanced geometries practiced recently have been summarized in this review. Classical approximations in macroscale flows have not applied to the flows with small hydraulic diameters, so, this subject has been paid attention by the researchers. Application areas of these structures are increasing continuously due to cooling need in small confined spaces. The related studies have been reviewed in a chronological manner and their parameters have been given in a table in order for the researchers to observe the scientific duration regarding the progresses on this subject. Almost all papers on this subject have been produced after 2000, therefore, this subject is considered as an actual one to improve and worth to study in the literature. This study can not only be evaluated as the beginning argument for the researchers involved in flow boiling process in mini and microchannel, but it also consists of new works on the investigated subject.Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi; "Research Chair Grant" National Science and Technology Development Agency; Thailand Research Fund; National Research University ProjectAll authors would like to thank the Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi for the support during this research in Thailand The authors would like to thank the "Research Chair Grant" National Science and Technology Development Agency, the Thailand Research Fund and the National Research University Project for the support