Unsteady flow models of wings and airfoils have been studied to understand the aerodynamic performance of natural flyers and provide improved maneuverability for micro aerial vehicles (MAVs). Vortex methods have been extensively applied to reduce the dimensionality of these aerodynamic models, based on the proper estimation of the distribution and evolution of the vortices in the wake. In such ...

In this paper, a comprehensive numerical study is presented for the fully developed two-dimensional flow of viscous incompressible fluid through a curved duct with square cross section. Numerical calculations are carried out over a wide range of the Dean number 6500 100   Dn for the curvature 5 . 0   . A temperature difference is applied across the vertical sidewalls for the Grashof number ...

The steady/unsteady flow of the BGK No. 1 supercritical airfoil is investigated by the solution of the Reynolds-Averaged Navier-Stokes equations with a two-equation k-ω turbulence model. The dual-time stepping method is used to march in time. Two steady cases ( 71 . 0 = Ma , 396 . 1 = α and 71 . 0 = Ma , 0 . 9 = α ) and one unsteady case ( 71 . 0 = Ma , 97 . 6 = α ), both with a far-stream 6 10...

Quantitative changes in groundwater and crises resulting from uncontrolled water extraction have turned water resources management into one of the supply-demand dilemmas in arid regions. The present study evaluated the quantitative situation of water resources in the Ardestan Plain adjoining the Ardestan desert by using the MODFLOW mathematical model. Simulation of groundwater flow in the stead...

T.J. Trella, U.S. Department of Tr~nsportation, Transportation Systems Center, Cambridge, Massachusetts 02142 and A mathematical model of non-linear reciprocating air-compressor discharge valve . system unsteady response was presented :n Part I. As a first step, to demonstrate the application of the unsteady modeling approach, a comparison of discharge discvalve response was made with a more po...

The use of pumps linked in parallel or series in large scale pipe systems is usually inevitable, to meet the required head and discharge. Transient flow occurs following a pump failure in a pump group as a result of variations in the flow rate. This research is an investigation about waterhammer caused by one or more pump-switch off in a pump group when they are connected in parallel. The opera...

The detailed analysis of the flow in the human lung is of high relevance for the optimization of mechanical ventilation. In this paper, the spatial and temporal development of the flow field in a realistic shaped model of the human lung is investigated for different pulsatile flow regimes. The model is based on the physiological data of a middle-aged and healthy male. The lung model consists of...

Although field observations of sudden spillway releases highlighted strong aeration of dam break wave flows, no study investigated these two-phase flow characteristics. New original experiments were conducted down a 24 m long stepped waterways. Dam break wave propagation showed an equivalent flow resistance similar to steady flow conditions (f ~ 0.05). Detailed unsteady air-water flow measureme...

The simultaneous flow of oil and water in porous media is described by relative permeability curves, mainly derived from laboratory experiments. Relative permeability is of paramount importance in predicting reservoir production performance and drive mechanisms and its value depends largely on the volume fraction of fluids present in the test samples. Nowadays X-ray scanners are one of the most...