Direct numerical simulation of supersonic boundary layers over a microramp: effect of the Reynolds number

Microvortex generators are passive control devices smaller than the boundary layer thickness that energise the boundary layer to prevent flow separation with limited induced drag. In this work, we use direct numerical simulations (DNS) to investigate the effect of the Reynolds number in a supersonic turbulent boundary layer over a microramp...

Impact of a forward-facing step on the development of crossflow instability

The impact of a forward-facing step (FFS) on the development of stationary crossflow instability is investigated on a swept wing model in a low-turbulence wind tunnel at chord Reynolds number of. Infrared thermography and particle image velocimetry measurements are used to quantify the transition location and growth of the crossflow...

Experimental control of swept-wing transition through base-flow modification by plasma actuators

Control of laminar-to-turbulent transition on a swept-wing is achieved by base-flow modification in an experimental framework, up to a chord Reynolds number of 2.5 million. This technique is based on the control strategy used in the numerical simulation by Dörr & Kloker (J. Phys. D: Appl. Phys., vol. 48, 2015b, 285205). A spanwise uniform...

Conditioning of cross-flow instability modes using dielectric barrier discharge plasma actuators

In the current study, selective forcing of cross-flow instability modes evolving on a swept wing at is achieved by means of spanwise-modulated plasma actuators, positioned near the leading edge. In the perspective of laminar flow control, the followed methodology holds on the discrete roughness elements/upstream flow deformation (DRE/UFD)...

Airfoil drag elimination and stall suppression via piezoelectric dynamic tangential synthetic jet actuators

This paper describes a new method for drag elimination and stall suppression via tangential synthetic jet actuators. This boundary layer control (BLC) method is shown to perform as well as continuous and normal synthetic jet BLC methods but without fouling difficulties, system-level complexity or extreme sensitivity to Reynolds number. Classical...

Description and validation of the two-dimensional test setup for multiple airfoils in the pressurized wind tunnel HST

A description is given of the two-dimensional test setup in the pressurized wind tunnel HST of the NLR, for the testing of multiple airfoils at high Reynolds numbers. Results of the first tests with this setup are validated. For this validation a number of additional tests were performed in the HST as well as in the atmospheric wind tunnel HST 3...