scholarly journals Numerical Simulation Techniques for the Prediction of Fluid-Dynamics, Combustion and Performance in IC Engines Fuelled by CNG

Author(s):  
Mirko Baratta ◽  
Ezio Spess
2014 ◽  
Vol 635-637 ◽  
pp. 35-39
Author(s):  
Dang Qin Xue ◽  
De Yong Lv ◽  
Jia Xi Zhang ◽  
Shu Lin Hou

Grid division is the geometric expression forms and vectors of CFD numerical simulation engineering problems. The quality of the grid has an important impact on the CFD accuracy and computational efficiency about CFD. In this paper, it compares the structured and non-structured grid process summary base on blade pump. During a large number of mechanical fluid grid division and performance calculations, and combining with the theoretical guidance based on rotating machinery fluid Dynamics calculations, it summarizes some experience and practice on blades grid division optimization.


This book provides students and researchers in fluid engineering with an up-to-date overview of turbulent flow research in the areas of simulation and modeling. A key element of the book is the systematic, rational development of turbulence closure models and related aspects of modern turbulent flow theory and prediction. Starting with a review of the spectral dynamics of homogenous and inhomogeneous turbulent flows, succeeding chapters deal with numerical simulation techniques, renormalization group methods and turbulent closure modeling. Each chapter is authored by recognized leaders in their respective fields, and each provides a thorough and cohesive treatment of the subject.


2016 ◽  
Vol 8 (10) ◽  
pp. 168781401667375 ◽  
Author(s):  
Wei Li ◽  
Xiaoping Jiang ◽  
Qinglong Pang ◽  
Ling Zhou ◽  
Wei Wang

Author(s):  
Manoochehr Darvish ◽  
Bastian Tietjen ◽  
Daniel Beck ◽  
Stefan Frank

The main focus of this work is on the geometrical modifications that can be applied to the fan wheel and the volute tongue of a radial fan to reduce the tonal noise. The experimental measurements are performed by using the in-duct method in accordance with ISO 5136. In addition to the experimental measurements, CFD (Computational Fluid Dynamics) and CAA (Computational Aeroacoustics) simulations are carried out to investigate the effects of different modifications on the noise and performance of the fan. It is shown that by modifying the blade outlet angle, the tonal noise of the fan can be reduced without affecting the performance of the fan. Moreover, it is indicated that increasing the number of blades leads to a significant reduction in the tonal noise and also an improvement in the performance. However, this trend is only valid up to a certain number of blades, and a further increment might reduce the aerodynamic performance of the fan. Besides modifying the impeller geometry, new volute tongues are designed and manufactured. It is demonstrated that the shape of the volute tongue plays an important role in the tonal noise generation of the fan. It is possible to reduce the tonal noise by using stepped tongues which produce phase-shift effects that lead to an effective local cancellation of the noise.


2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Krzysztof Wołosz ◽  
Jacek Wernik

AbstractThe paper presents the part of the investigation that has been carried out in order to develop the pneumatic pulsator which is to be employed as an unblocking device at lose material silo outlets. The part of numerical simulation is reported. The fluid dynamics issues have been outlined which are present during supersonic airflow thought the head of the pulsator. These issues describe the pneumatic impact phenomenon onto the loose material bed present in the silo to which walls the pulsator is assembled. The investigation presented in the paper are industrial applicable and the result is the working prototype of the industrial pneumatic pulsator. The numerical simulation has led to change the piston shape which is moving inside the head of the pulsator, and therefore, to reduce the pressure losses during the airflow. A stress analysis of the pulsator controller body has been carried out while the numerical simulation investigation part of the whole project. The analysis has made possible the change of the controller body material from cast iron to aluminium alloy.


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