Thin aerofoils are prone to localized flow separation at their leading edge if subjected to moderate angles of attack α. Although 'laminar separation bubbles' at first do not significantly alter the aerofoil performance, they tend to 'burst' if α is increased further or if perturbations acting upon the flow reach a certain intensity. This then either leads to global flow separation (stall) or t...

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3D modeling of Pd/α-Al2O3 hollow fiber membrane by using computational fluid dynamic for hydrogen separation from H2/N2 mixture was considered in steady and unsteady states by using the concept of characteristic time. Characteristic time concept could help us to design and calculate surface to volume ratio and membrane thickness, and adjust the feed conditions. The contribution of resistance be...

Vertical axis wind turbine (VAWT) blades undergo dynamic separation due to the large angle of attack variation they experience during a turbine rotation. The flow over a single blade was modeled using a sinusoidally pitching and surging airfoil in a constant free stream flow at a mean chord Reynolds number of 10. Two-dimensional, time resolved velocity fields were acquired using particle image ...

The separation efficiencies of three different asymmetrical flow field-flow fractionation (AF4) channel designs were evaluated using polystyrene latex standards. Channel breadth was held constant for one channel (rectangular profile), and was reduced either linearly (trapezoidal profile) or exponentially (exponential profile) along the length for the other two. The effective void volumes of the...

A microfluidic system with a wide surface area per unit volume has the potential for use in highly efficient chemical synthesis, separation, and extraction. In the case of efficient water/oil separation and material extraction, it becomes important to form a stable two-layer laminar flow interface. Previously, we developed a silicon/glass microfluidic reactor, in which microchannel inner walls ...

Introduction Jet pumps are static components that can be used in closed-loop, traveling wave thermoacoustic devices to suppress a time-averaged mass flux (Gedeon streaming) that can exist [2]. The minimization of convective heat transport caused by this mass flux is of vital importance due to the detrimental effect it has on the device’s efficiency. Jet pumps have an asymmetric shape, resulting...

Separation kernels are the holy grail of secure systems, remaining elusive despite years of research into their design, implementation, and analysis. Though separation kernel research has achieved many successes, the disconnect between information flow theory and system implementation is a significant barrier to further progress. In this paper, we show how a particular branch of information flo...

A NUMBER of military and civilian applications require efficient operation of airfoils in low chord Reynolds numbers. The applications include propellers, sailplanes, ultralight mancarrying/man-powered aircraft, high-altitude vehicles, wind turbines, unmanned aerial vehicles, and micro air vehicles. Careful management of boundary layers on low-Reynolds-number airfoils is required to alleviate t...

We present and demonstrate a method for blind separation and bearing estimation of broadband traveling waves, impinging on a sensor array with dimensions smaller than the shortest wavelength in the sources. By sensing spatial and temporal gradients of the received signal, the problem of separating mixtures of time-delayed sources reduces to that of separating instantaneous mixtures of the gradi...