A numerical study of control surface buzz using computational fluid dynamic methods

1992 ◽  
Author(s):  
DENNIS FUGLSANG ◽  
LARRY BRASE ◽  
SHREEKANT AGRAWAL
Keyword(s):  
Computational Fluid Dynamic ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Control Surface ◽  
Dynamic Methods

Evaluation of computational fluid dynamic methods for reactor safety analysis (ECORA)

2005 ◽  
Vol 235 (2-4) ◽  
pp. 359-368 ◽  
Author(s):  
M. Scheuerer ◽  
M. Heitsch ◽  
F. Menter ◽  
Y. Egorov ◽  
I. Toth ◽  
...  
Keyword(s):  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Safety Analysis ◽  
Reactor Safety ◽  
Dynamic Methods

scholarly journals Experimental and numerical study on the performance of an axial fan with a Gurney flap

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880380 ◽  
Author(s):  
Liu Chen ◽  
Haijun Xie ◽  
Jun Xu ◽  
Ren Dai ◽  
Jian Chen
Keyword(s):  
Computational Fluid Dynamic ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Pressure Rise ◽  
Field Analysis ◽  
Horizontal Wind ◽  
Tip Leakage Flow ◽  
Axial Fan ◽  
Gurney Flap ◽  
Lift Enhancement

Gurney flap is a miniature lift-enhancement device installed at the airfoil trailing edge and has been successfully applied to fixed wing aircraft and low-speed horizontal wind turbines. In this article, Gurney flap is extended to increase pressure output of a diffusive cascade flow in rotating turbomachinery, which is complicated for its three dimensionalities and diffusive separation characteristics. Wind tunnel tests and computational fluid dynamic simulations were accomplished on an axial fan profiled with an NACA 65-(12)10 airfoil to investigate the effects of Gurney flap on the performance of a high solidity. We present the detailed flow features of the fan with and without Gurney flap after validating the simulation results with the experimental datum. The experimental results show positive Gurney flap effects on fan’s pressure rise and flow rate improvement. However, negative Gurney flap effects on fan’s efficiency are more evident than Gurney flap on isolated airfoils. Detailed flow field analysis from computational fluid dynamic computation reveals that the increased airfoil pressure loading along the fan blade chord strengthens the tip leakage flow, which induces more tip second flow losses than in the baseline fan. In addition to the positive lift enhancement, the net Gurney flap effect in diffusion cascade is influenced by the three-dimensional flow structure.

Numerical Study of Coal Composition Effects on the Performance of Gasification Through Computational Fluid Dynamic

2019 ◽  
Vol 17 (7) ◽  
Author(s):  
Imran Nazir Unar ◽  
Suhail Ahmed Soomro ◽  
Ghulamullah Maitlo ◽  
Shaheen Aziz ◽  
Rasool Bux Mahar ◽  
...  
Keyword(s):  
Computational Fluid Dynamic ◽  
Stokes Equations ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Great Influence ◽  
Electricity Production ◽  
Combustion Model ◽  
Heating Value ◽  
Coal Composition ◽  
Coal Reserves

Abstract Pakistan is very rich in coal reserves specifically after exploration of Thar coal reserves. At the same time country is facing energy crises due to shortage or unavailability of sustainable fuel supply at a cheaper rate. One potential solution is coal gasification which gives clean synthetic gas usually called syngas for use as an alternative fuel source for electricity production at a cheaper rate as well as a source of recovering different chemicals used as basic raw materials in other industries. Numerical simulations have been performed in this work for the gasification process of indigenous coal on a 2D computational fluid dynamic (CFD) model of downdraft entrained-flow gasifier using commercial CFD software FLUENT®6.3.26. Navier-stokes equations along with transport equations for species have been solved using eddy-dissipation combustion model. The compositions of indigenous coals (Thar, Lakhra, and Sonda) were used in simulations as gasification feedstock. Rich oxidant conditions 95 % O2 and 5 % N2 were set for gasification. The gasification performance was studied by comparing efficiencies of gasification and quality of syngas produced for three types of coal feedings. The temperature and pressure profiles inside the gasifier were also studied. From simulation results, the great influence of coal composition was observed in the performance of gasification. Lakhra coal produced syngas with a maximum heating value of 20.55 MJ/kg whereas sonda coal produced syngas with a minimum heating value of 17.96 MJ/kg.

Some observations on the initiation and onset of detonation

2012 ◽  
Vol 370 (1960) ◽  
pp. 715-739 ◽  
Author(s):  
Geraint Thomas
Keyword(s):  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Experimental Studies ◽  
Practical Applications ◽  
Deflagration To Detonation Transition ◽  
Dynamic Methods ◽  
Detonation Transition ◽  
Transition To Detonation

The results of experimental studies during which transition to detonation events occurred are presented. These observations and their interpretation are then discussed, and the conditions for the onset of detonation are described, with particular attention paid to the nature of the phenomena of deflagration-to-detonation transition. The resulting implications for predicting detonation evolution using computational fluid dynamic methods in practical applications are also discussed.

Numerical Analysis of Turbulent Natural Convection Heat Transfer Inside a Trangular Shaped Enclosure Utilizing Computational Fluid Dynamic Code

2006 ◽  
Author(s):  
M. Ghassemi ◽  
M. Fathabadi
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Computational Fluid Dynamic ◽  
Numerical Study ◽  
Control Volume ◽  
Fluid Dynamic ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Turbulent Natural Convection

Numerical study of turbulent natural convection heat transfer inside a triangular shaped enclosure is considered. A k-ε model along with mass, momentum and energy equations is utilized to solve the flow and temperature field. A computational fluid dynamic based code (CFD), Fluent, that is commercially available is used is to solve the non-linear partial differential equations. The steady state, two-dimensional, incompressible heat transfer results are presented in terms of non dimensional temperature, heat flux, and the Nusselt number as a function of aspect ratio (Ar), angle between sloped and horizontal wall (θ), and the Grashof number (Gr). The obtained results are compared with results that are calculated by a control volume based method. Results obtained by the Fluent code shows closed agreement with the control volume ones. It is again shown that heat transfer is higher in turbulent settings and results are function of the angle between two walls of the enclosure (θ).

NUMERICAL STUDY OF NANOFLUID FLOW AND HEAT TRANSFER IN MICROCHANNELS

2006 ◽  
Vol 05 (06) ◽  
pp. 747-752 ◽  
Author(s):  
DIAO XU ◽  
LUNSHENG PAN
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Computational Fluid Dynamic ◽  
Dynamic Method ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Nanofluid Flow ◽  
Viscous Shear Stress ◽  
Flow And Heat Transfer ◽  
Viscous Shear

It is known that the metal nanoparticles, when dispersed in fluids to form nanofluids, improve the heat conductivity of the fluids. The present paper studies the flow and heat transfer of the nanofluids in a microchannel by using Computational Fluid Dynamic method. It is found that although the nanoparticles enhance the heat transfer of the fluids about certain percent, the nanoparticles also cause a big increase of viscous shear stress on the wall, which causes an increase of the power consumption for driving the nanofluids through the microchannel.

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