Previous studies have demonstrated the capability of superhydrophobic surfaces to produce slip flow and drag reduction, which properties hold considerable promise for a broad range of applications. However, in order to implement such surfaces for practical utilizations, environmental factors such as water movement over the surface must be observed and understood. In this work, experiments were ...

We use high-resolution, three-dimensional hydrodynamics simulations to study the hydrodynamic and gravitational interaction between stellar companions embedded within a differentially rotating common envelope. Specifically, we evaluate the contributions of the non-axisymmetric gravitational tides and pressure forces to the drag force and, hence, to the dissipation rate and the mass accumulated ...

We investigate theoretically the onset of capillary-gravity waves created by a small object moving at the water-air interface. It is well established that, for straight uniform motion, no steady waves appear at velocities below the minimum phase velocity c(min)=23 cm/s. At higher velocities, the emission of capillary-gravity waves creates an additional drag force. The behavior of this force nea...

Three-dimensional numerical simulations using FLUENT [1] were performed to model the airflow over the Sunseeker, an award-winning solar car that was designed and built at Western Michigan University. Converged numerical solutions on three different grids are reported and compared with the available experimental data, which include the lift and the drag coefficients. Also reported are the result...

To understand / evaluate behaviour of these complex jets freestream interactions, experiments were carried out in the freestream Mach number range of 0.6 to 1.8 varying jet pressure ratios in the range of 1 to about 15 on a twin jet afterbody configuration. Test results show that afterbody total drag in general increased (for the Mach number range of this investigation) with the increase in jet...

Two dual-point design procedures were developed to reduce the objective function of a baseline airfoil at two design points. The rst procedure to develop a redesigned airfoil used a weighted average of the shapes of two intermediate airfoils redesigned at each of the two design points. The second procedure used a weighted average of two pressure distributions obtained from an intermediate airfo...

Our previous studies on solute drag on frog skin and synthetic heteropore membranes have been extended to a synthetic homopore membrane. The 150-A radius pores of this membrane are formed by irradiation and etching of polycarbonate films. The membrane is 6-microm thick and it has 6 x 10(8) pores cm(-2). In this study, sucrose has been used as the driver solute with bulk flow blocked by hydrosta...

Adaptive mesh refinement is one of the most important tools in Computational Fluid Dynamics (CFD) for solving complex engineering design problems. The paper investigates two practical transonic aerofoil design optimization problems using a genetic algorithm coupled with an Euler aerodynamic analysis tool. The first problem consists in the minimization of transonic drag whereas the second is a r...

An experimental study was performed to investigate the lift and drag coefficient of multiple wing. Most of the previous works carried out to increase the lift force and reduce the drag force having the more efficient and effective design. The aim of this project is to investigate the effect of multiple wings on lift and drag force. To perform this investigation a model of multiple wings is cons...

The distribution of dynamic pressure behind a Harris' hawk's wing was sampled using a wake rake consisting of 15 pitot tubes and one static tube. The hawk was holding on to a perch, but at an air speed and gliding angle at which it was capable of gliding. The perch was instrumented, so that the lift developed by the wing was known and the lift coefficient could be calculated. The mean of 92 est...