Showing 4 results for Ehghaghi
Volume 14, Issue 2 (summer 2024)
Abstract
In recent decades, digitalization has emerged as a key factor in the transformation of industries. Along with the advances that digitization has brought for industries, environmental and social issues have also been challenged. In this context, Toman's use of lean production principles along with digital technologies has emerged as a sustainable strategy in order to reduce the negative effects on the environment, society and the challenges facing it. But the important point in between is the importance of social aspects along with technical aspects. The underlying importance of the category of culture as a social aspect in the organization is of great importance for the foundation of these principles. For this reason, in this research, the digitization of production has been investigated on sustainable performance with the mediating role of lean production and moderator of lean culture. The statistical sample consisted of 211 companies active in the value chain of automobiles and related parts, and a standard questionnaire was distributed among them using a simple random method. Smart-PLS3 software was used for analysis. The results of the hypothesis test showed that digitization and lean production have a significant effect on the realization of sustainable performance. Also, by using digital technologies and establishing a pure culture, it is possible to improve the performance of industries and reduce environmental and social impacts.
Mir Boyouk Ehghaghi, Mohammad Vajdi,
Volume 15, Issue 3 (5-2015)
Abstract
As pumps are used frequently in industrial plants, their performance improvement is important. In this study, performance improvement of centrifugal pumps by application of splitter blades have been investigated both numerically and experimentally. Radial impellers with different length of splitter blades have been manufactured and tested to obtain performance charts. On the other hand, the flow in impeller and volute has been investigated numerically by ANSYS-CFX commercial code. Numerical study has been done using Finite volume method and k-ωSST turbulence model. Rotating and stationary frames have been used to analyze flow in impeller and volute respectively and the results have been coupled by Frozen Rotor. Three impellers with the lengths of splitter blades equal to 0, 33% and 66% of original blades were tested. Results show head increase when the splitter blades added while the amount of increase depends on the splitter blades length. At BEP (Best Efficiency Point) the maximum head increase was reported for impeller type three (the length of splitters equal to 66% of original blades) about 10.5 percent. It should be noted that as the capacity tends to BEP, the effect of splitter blades is more significant.
Salar Talebi, Hadi Fallah Ardeshir, Mir Boyouk Ehghaghi, Mahdi Nili Ahmad Abadi,
Volume 16, Issue 12 (2-2017)
Abstract
In the present work, an inverse design algorithm called Ball-Spine (BSA) is developed as a quasi-3D method on the meridional plane of a centrifugal pump impeller with rotating frame and incompressible viscous flow within it, with the aim of improving its performance. In this method, numerical analysis of viscous flow on a thin plane of flow between two blades using a 3D viscous flow solver is combined with BSA, which modifies hub and shroud geometries. Namely, instead of solving inviscid quasi-3D flow equations in the meridional plane, full 3D Navier-Stokes equations is solved on the thin plane of flow. To show the validity of the present work, centrifugal pump is numerically evaluated and numerical results are compared with experimental results, and flow field in the meridional plane of pump impeller is obtained using quasi-3D method. By studying the algorithm in the rotating geometry and choosing static pressure and reduced pressure as target parameters the ability of performance of the algorithm is assessed. After that, the new impeller geometry is obtained in conformity with the modified pressure distribution, by defining target pressure distribution on the hub and shroud surfaces of the conduit and trying to eliminate excess pressure gradients. Obtained results indicate good rate of convergence and desirable stability of BSA in the design of rotating conduits with incompressible viscous fluids. By using the above-mentioned optimization method following results was observed: increase of static pressure along streamline, 1% of increase in the pump total head, delay in impeller cavitation inception.
Mir Boyok Ehghaghi, Mohammad Vajdi, Mohammad Namazizadeh, Maryam Hajipour,
Volume 17, Issue 3 (5-2017)
Abstract
Centrifugal pumps as a heart of the system which are used to move fluids are used widely in most of the industries and have considerable contribution in the amount of energy consumption, so improving of their performance has been attended for researchers .In this paper the aim of studying is the effect of double splitter blades on pump’s performance numerically and experimentally. Three type impellers have been made as experimental investigation. Pump with this impellers is tested and extracted the performance curve. Also, for investigation of the flow pump has been simulated numerically by ANSYS-CFX commercial code. Numerical method of finite volume with k-ω SST turbulence model for numerical analysis. Numerical and experimental results show reasonable agreement that increasing of head and variation of NPSHR due to adding of double splitter blades. The maximum head increased was obtained related to third type of Impeller about 6.33 percent. Furthermore, third type is selected as best impeller. Also, it is observed that around point of designing of pump the effect of double splitter blades on pump’s performance is more significant and deviation from this point will decrease the effect of it.
