Boundary Layer Suction on a Horizontal Axis Wind Turbine: An Aerodynamic Design of a Thick Airfoil for Application

Wind Turbine Airfoils with Boundary Layer Suction: A Novel Design Approach

Actiflow is designing a new generation of wind turbine rotors enhanced by the use of passively powered boundary layer suction to improve the aerodynamic and struc­tural performance of thick profiles. As a part of this effort, this work explores the design space of airfoils with(out) boundary layer suction, outlines major design trends and...

Deconvolution Filters for Dynamic Rocket Thrust Measurements

Every spacecraft carries small rocket engines called thrusters for the purpose of orbit and position corrections in space. A precise operation of the thrusters saves fuel and a lower fuel consumption can extend the service life of the spacecraft. Precise thrust levels can be better obtained by pulsed firing than by continuous firing of the...

Effects of Increasing Aerothermodynamic Fidelity on Hypersonic Trajectory Optimisation for Flight Testing Purposes

In a previous study, the optimal re-entry trajectory of Hyperion-2 has been derived. The mission of the vehicle is to measure hypersonic boundary-layer transition, a phenomena in which the laminar boundary layer turns into a turbulent boundary layer. This is an important feature in hypersonic flow to investigate, as it introduces peak heating...

Experimental study on the energy deposition of an ns-DBD plasma actuator and its effect on a laminar boundary layer

An experimental study aimed at the influence of different barrier materials on the energy deposition of nanosecond pulsed dielectric barrier discharge (ns-DBD) plasma actuator was carried out. Additionally, the direct effect of the discharge of an ns-DBD plasma actuator on a low velocity laminar boundary layer was investigated. Three barrier...

Dimension-adaptive sparse grid for industrial applications using Sobol variances

The area of interest for this study is the field of uncertainty quantification in computational fluid dynamics. The goal is to contribute to a new method to perform uncertainty quantification analyses for industrial, computationally expensive CFD simulations. To this end, an adaptive grid refinement method is developed. The existing sparse grid...

The influence of laminar-turbulent transition on the perfomance of a propeller

The influence of laminar-turbulent transition on a propeller blade’s performance has been investigated in this study, both numerically and experimentally. The computational fluid dynamics (CFD) is performed using the TAU code developed by the German Aerospace Center, as well as an existing propeller lifting-line code. The laminar-turbulent...

Aeroacoustics and Flow Dynamics of an airfoil with a Gurney flap using TR-PIV

Aircraft noise has come under severe scrutiny due to growing number of airports and airline operations. The noise generated by high lift devices is now comparable to the turbofan engines due to increasing bypass ratios. A Gurney flap is a suitable starting point to study trailing edge flap aeroacoustics due to additional lift characteristics and...

Noise Prediction of a NACA 0015 Airfoil with Gurney Flap: A study based on Time-Resolved Particle Image Velocimetry

Air traffic noise, especially during the aircraft take-off and landing, has been universally acknowledged as a nuisance, for which reason, the International Civil Aviation Organization(ICAO) has ratified articles and established specifications aiming at the attenuation of air traffic noise, such as the Annex 16. The implementation of large...

Spatially mass-, kinetic energy- and helicity-preserving mimetic discretization of 3D incompressible Euler flows

Based on the recently developed mimetic spectral element method, we propose an effective numerical scheme for solving three-dimensional periodic incompressible Euler flows, which spatially preserves mass, kinetic energy and helicity. Preserving multiple integral invariants numerically will significantly contribute to the stability and accuracy...

Efficiency and de-icing capability of nanosecond pulsed dielectric barrier discharge plasma actuators

In this work a study was performed on the electrical, fluid-mechanical and net efficiency of nanosecond-pulsed dielectric barrier discharge (ns-DBD) plasma actuators. The plasma actuator efficiency was tested for dielectric barriers with a thickness between 0.5 and 1.5mm and made out of four different materials: Kapton, Lexan, PTFE and silicone...

The 3D separation behaviour of a micro-ramp controlled oblique shock-wave reflection: An experimental Investigation

Oblique Shock-Wave Reflections or Shock Wave-Boundary Layer interactions (SWBLI) are complex phenomena which commonly occur in high speed flight. SWBLIs can have catastrophic consequences on the aircraft due to shock induced separation and unsteadiness of the interaction. These adverse effects can be mitigated by manipulating the boundary layer,...

Development and Validation of an End-to-End Simulator for Frequency Scanning Filtered Rayleigh Scattering Techniques

An end-to-end simulator for frequency scanning methods of filtered Rayleigh scattering (FSM-FRS) has been developed during the master thesis research at the German Aerospace Center (DLR). It can model several frequency scanning filtered Rayleigh scattering methods and predict the accuracies in measuring flow temperature, pressure, and velocity....

Stability analysis for two-phase pipe flow