Manipulation Of Large Scales Via A Spanwise Array Of Wall-Normal Jets In A Turbulent Boundary Layer: An Attempt At Large Scale Control For Drag Reduction

In recent years, research for turbulent boundary layer (TBL) has shifted towards developing novel approaches to reduce drag. This shift is driven by new industrial standards emphasizing fuel-efficient and environmentally friendly air transportation. As wall-bounded turbulence plays a significant role in the overall drag experienced by an...

Experimental investigation of compliant coatings in turbulent boundary layers in air

Inspired by the dolphin skin, compliant coatings have been researched as a passive flow control solution to reduce drag. Both successful and drag-increasing experiments can be found in the literature. However, the mechanism is not well understood neither the combination of surface properties and flow conditions that yield a drag reduction. At...

Aerodynamic interaction between propellers of a distributed-propulsion system in forward flight

This article describes an experimental investigation of the aerodynamic interaction that occurs between distributed propellers in forward flight. To this end, three propellers were installed in close proximity in a wind tunnel, and the changes in their performance, flow-field characteristics, and noise production were quantified using...

Stall Cell Characteristics: An experimental investigation of the airfoil influence

Stall is traditionally divided in three types of stall behaviour, these have been regarded as two dimensional and dominated by the airfoil shape. However one of these types of stall behaviour, trailing edge stall, has been shown in literature to be three dimensional by forming stall cells along the wing span. Stall cells are coherent flow...

Spanwise wall oscillation as a drag reduction technique: PIV-based evaluation of turbulent skin-friction drag reduction over a flat plate by spanwise wall oscillation

Reduction of skin-friction drag over a fully developed canonical zero-pressure gradient turbulent boundary layer (ZPGTBL) subjected to spanwise oscillation is measured using planar particle image velocimetry (PIV). The experiments are conducted at Re_θ of 1000 and 1800, the chosen range of spanwise oscillations amplitude and frequency...

Design and testing of a low subsonic wind tunnel gust generator

This paper summarises the design of a gust generator and the comparison between high fidelity numerical results and experimental results. The gust generator has been designed for a low subsonic wind tunnel in order to perform gust response experiments on wings and assess load alleviation. Special attention has been given to the different...

Design and testing of a low subsonic wind tunnel gust generator

This paper summarises the design of a gust generator and the comparison between high fidelity numerical results and experimental results. The gust generator has been designed for a low subsonic wind tunnel in order to perform gust response experiments on wings and assess load alleviation. Special attention has been given to the different design...

Wind turbine aerodynamics in yaw: Unravelling the measured rotor wake