Unsteady two-dimensional stagnation point flow of an incompressible viscous fluid over a flat deformable sheet is studied when the flow is started impulsively from rest and the sheet is suddenly stretched in its own plane with a velocity proportional to the distance from the stagnation point. After a similarity transformation, the unsteady boundary layer equation is solved numerically using the...

Flow volumes [1] are extended for use in unsteady (timedependent) flows. The resulting unsteady flow volumes are the 3 dimensional analog of streaklines. There are few examples where methods other than particle tracing have been used to visualize time varying flows. Since particle paths can become convoluted in time there are additional considerations to be made when extending any visualization...

We report on the lift and drag forces on a stationary sphere subjected to a wall-bounded oscillatory flow. We show how these forces depend on two parameters, namely, the distance between the particle and the bounding wall, and on the frequency of the oscillatory flow. The forces were obtained from numerical solutions of the unsteady incompressible Navier-Stokes equations. For the range of param...

The interaction between an initially laminar boundary layer developed spatially on a flat plate under the influence of vortex shedding induced from a rotating circular cylinder has been simulated numerically. The rotational speed of the cylinder is varied to generate the vortex shedding of different intensities. Also the flat plate is kept at different positions from the cylinder. Due to asymme...

Operational problems and system damage have been linked to the flow regime transition between free surface and pressurized flow in rapidly filling stormwater and combined sewer systems. In response, emphasis has been placed on the development of numerical models to describe hydraulic bores and other flow phenomena that may occur in these systems. Current numerical models are based on rigid colu...

Drag force control via energy deposition in an oncoming flow is a wide area of interest in aerospace sciences. Recently, investigations on the effect of combining energy sources have been conducted. The possibility of coupling microwave (MW) discharges or MW and laser energy deposition is discussed. In the present work, the flow details accompanying the interaction of a combined energy release ...

Complex heat transfer phenomena (including unsteady state conduction, convection and solidification processes) occur in steel belt conveyer sulfur granulating method. Numerical simulation of this technique is performed via a comprehensive and multifaceted one dimensional model. Since the air situated between the adjacent sulfur pastilles is essentially stagnant, therefore, the surface tempe...

A computational study was conducted to investigate the unsteady quasi-two-dimensional flow around a streamlined NASA low-speed GA(W)-1 airfoil and a corrugated dragonfly airfoil at the Reynolds numbers of 68,000 and 55,000. Both 2D and 3D simulations were carried out by solving the unsteady Navier-Stokes equations to predict the behavior of the unsteady flow structures around the airfoils at di...

in petroleum production, produced water re-injection (pwri) has earned much interest among disposal methods of the produced water. however, presence of the contaminants in the produced waters usually results in formation damage in well bores and their surrounding fracture systems. in the present study, modeling of external cake formation on a fracture in unsteady-state conditions is discussed. ...

This paper focuses on the temporal and spatial evolutions of critical flow under unsteady rapidly varied conditions, which is defined based different viewpoints steady gradually conditions in classical fluid mechanics theory. So far, fundamental theory largely unknown for conditions. Taking a Gauss-type weir as an example, this work investigates comprehensively comparatively influences unsteadi...