Numerical Predictions of Turbulent Mixed Convection Heat Transfer to Supercritical Fluids Using Various Low Reynolds Number k-e Turbulence Models

Mahdi Mohseni; ???? ????????

Volume 7, Issue 2 , September 2010, Pages 69-79

  There are a number of systems in which supercritical cryogenic fluids are used as coolants or propellant fluids. In some modern military aircraft, the fuel is pressurized above its critical point and used as a coolant to remove heat from the aircraft engine. Accurate prediction of heat transfer coefficients ...  Read More

Design of Nonlinear Robust Controller and Observer for Control of a Flexible Spacecraft

maryam malekzadeh; Abolqasem Naghash; H.Ali Talebi

Volume 7, Issue 2 , September 2010, Pages 81-91

  Two robust nonlinear controllers along with a nonlinear observer have been developed in this study to control a 1D nonlinear flexible spacecraft. The first controller is based on dynamic inversion, while the second one is composed of dynamic inversion and µ-synthesis controllers. The extension of dynamic ...  Read More

A Comparison of Smart and Conventional Flaps Close to Ground on Aerodynamic Performance

mohammad Hassan Djavareshkian; A. Esmaeli; A. Parsania

Volume 7, Issue 2 , September 2010, Pages 93-106

  The prediction of aerodynamic characteristics and smart flap of airfoil under the ground effect are carried out by the integration of computational fluid dynamics. Considering different types of beams, a parametric bending profile of a smart flap is designed. Cantilever beam with uniformly varying load ...  Read More

Solution of Thermo-Fluid problems in Bounded Domains via the Numerical Panel Method

Ali Ashrafizadeh; A. A. Hosseinjani

Volume 7, Issue 2 , September 2010, Pages 107-122

  The classical panel method has been extensively used in external aerodynamics to calculate ideal flow fields around moving vehicles or stationary structures in unbounded domains. However, the panel method, as a somewhat simpler implementation of the boundary element method, has rarely been employed to ...  Read More

Effects Of Frequency Variation At Inlet Flow On The Vortex Shedding Frequency Behind A Circular Cylinder

edris yousefirad; Mohammad Pasandidefard Fard

Volume 7, Issue 2 , September 2010, Pages 123-129

  In many applications the flow that past bluff bodies has frequency nature (oscillated) and it is not uniform. This kind of flow has effects on the formation of vortex shedding behind bluff bodies. In this paper the flow around a circular cylinder was numerically simulated. The effects of frequency variation ...  Read More

Wind Tunnel Investigation of Pressure Distribution and Transition Position of a Swept 3D Wing

Mohammad Reza Dr. Soltani; M. Masdari; M. Seidjafari; Kaveh Ghorbanian

Volume 7, Issue 2 , September 2010, Pages 132-137

  Extensive wind tunnel tests are conducted to evaluate surface pressure distribution of a semi span swept wing. The wing section has a laminar flow airfoil similar to NACA 6-series airfoils. The investigations are conducted at various speeds and angles of attack. Surface pressure distribution over the ...  Read More

Improvement in Differential GPS Accuracy using Kalman Filter

Mohammad Reza Mosavi; Azadeh Nakhaei; Sh. Bagherinia

Volume 7, Issue 2 , September 2010, Pages 139-150

  Global Positioning System (GPS) is proven to be an accurate positioning sensor. However, there are several sources of errors such as ionosphere and troposphere effects, satellite time errors, errors of orbit data, receivers errors, and errors resulting from multi-path effect which reduce the accuracy ...  Read More