This paper presents an experimental investigation of a propeller operating at low Reynolds numbers and provides insights into the role aerodynamic flow features on both performances noise generation. A tip number regime is tested in anechoic wind tunnel advance ratio ranging from 0 to 0.6. Noise measured by means microphone array, while forces are with load torque cells. Oil-flow visualizations...

Effects of flexible membrane mounted over suction surface NACA 4412 airfoil were experimentally investigated at Reynolds number 5x104 and low aspect ratio (AR=1) in this paper. The smoke-wire visualization method has been performed for flow to demonstrate phenomena as laminar separation bubble (LSB), leading edge z/c=0.4 tip vortices z/c=0.1. Values velocity, stress turbulence statistics measur...

For the first time, a laminar separation membrane was assembled from atom-thick MoS2 sheets and exhibited a water permeance of 245 L h(-1) m(-2) bar(-1), which was 3-5 times higher than that of graphene oxide membranes without degradation of the rejection ratio (89%) for Evans blue molecules.

This paper describes a novel approach in simulating laminar to turbulent transition by using two-equation models. The Total Stresses Limitation(TSL) concept is used to make the two-equation model capable of predicting high Reynolds number transitional ow. To consider the transition triggered by laminar separation at low Reynolds number location, which commonly occurs in high speed ow, a sensor ...

This paper describes a novel approach in simulating laminar to turbulent transition by using two-equation models. The Total Stresses Limitation (TSL) concept is used to make the two-equation model capable of predicting high-Reynolds-number transitional ow. In order to handle the transition triggered by laminar separation at a low Reynolds number location, which commonly occurs in high speed ow,...

During the past several years we have performed a considerable amount of investigations of basic instability mechanisms in various laminar separation bubbles. Because of the high sensitivity of the flow with respect to intrusive measurement techniques and the difficulties of computing the flow field via boundary-layer equations or RANS our research relies primarily on direct numerical simulatio...

submitted for the Joint EWA and PivNet 2 Workshop on CFD, PIV and Experiments in Aerodynamics, May 10–11, 2005, Göttingen, Germany Combined Investigations on Disturbance Development in a Laminar Separation Bubble by Means of PIV, LDA and DNS M. Lang†, O. Marxen‡, U. Rist‡ ‡ Institut für Aerodynamik und Gasdynamik (IAG), Universität Stuttgart † current affiliation: Behr GmbH & Co. KG Introductio...

As a new type of the propulsive devices, cycloidal rotor has been attracting more attention recently. The present work concentrates on analysis performance and internal flow field two-bladed operating at low Reynolds numbers, with special emphasis understanding how structure affects different working conditions. symmetrical/asymmetrical pitching motions are evaluated initially primary results s...

purpose: to determine the dissection level during deep lamellar keratoplasty (dalk) using the big-bubble technique by light microscopy (lm) and transmission electron microscopy (tem). methods: descemet’s membrane (dm) and stromal tissue of 4 keratoconic eyes were removed because of inadvertent intraoperative dm perforation during dalk which was converted to penetrating keratoplasty. these speci...