Julien Deparday
Experimental fluid dynamics. My research and experience.
Archives
Study of the wall pressure variations on the stall inception of a thick cambered profile at high Reynolds number
in Phys. Rev. Fluids, 9, 014605, 2024 We present an experimental study of the aerodynamic forces on a thick and cambered airfoil at a high Reynolds number (Re) (3.6×10^6), which is of direct relevance for wind turbine design. Unlike thin airfoils at low chord-based Reynolds numbers, no consistent description currently exists for the stall process…
Hybrid Model for Inflow Conditions Inference on Airfoils Under Uncertainty
in AIAA Journal, vol. 61, no. 11, pp. 4913-4925, 2023 Estimation of inflow conditions, such as wind speed and angle of attack, is vital for assessing aerodynamic performance of a lifting profile. This task is particularly challenging in the field due to the inherent stochasticity of the inflow variables. In practice, the field installation of…
Aerosense: Long-Range Bluetooth Wireless Sensor Node for Aerodynamic Monitoring on Wind Turbine Blades
in Journal of Physics: Conference Series, 2265(2):022074 , 2022 Predictive maintenance and structural health monitoring are challenging and promising research fields today. In particular, cost-effective and long-term monitoring of wind turbines has been proven to be one of the key elements to successfully increase their efficiency. Accurate numerical modeling and real-time control-in-the-loop play an increasingly…
An experimental system to acquire aeroacoustic properties on wind turbine blades
in Journal of Physics: Conference Series, 2265(2):022089, 2022 Wind turbine noise is a key issue preventing the successful exploitation of the full potential of wind energy throughout the world, especially in urban areas. To better assess and predict wind turbine noise, several aeroacoustic simulations and models have been developed over the past. Many semi-empirical models…
Experimental quantification of unsteady leading-edge flow separation
in Journal of Fluid Mechanics, vol. 941, A60, 2022 We propose here a method to experimentally quantify unsteady leading-edge flow separation on aerofoils with finite thickness. The methodology relies on the computation of a leading-edge suction parameter based on measured values of the partial circulation around the leading edge and the stagnation point location. We…
The dynamics and timescales of static stall
in Journal of Fluids and Structures, 104:103304, 2021 Airfoil stall plays a central role in the design of safe and efficient lifting surfaces. We typically distinguish between static and dynamic stall based on the unsteady rate of change of an airfoil’s angle of attack. Despite the somewhat misleading denotation, the force and flow development of…
Stall Delay and Leading-Edge Suction for a Pitching Airfoil with Trailing-Edge Flap
in AIAA Journal, 58(12):5146-5155, 2020 The flow around a pitching NACA0015 airfoil with an oscillating trailing-edge flap is experimentally investigated to characterize the influence of the flap kinematics on the development of dynamic stall. We specifically focus on the timing of the stall development and critical values of the leading-edge suction parameter as potential stall…
Modeling the interplay between the shear layer and leading edge suction during dynamic stall
in Physics of Fluids, 31:107104 , 2019 The dynamic stall development on a pitching airfoil at Re = 106 was investigated by time-resolved surface pressure and velocity field measurements. Two stages were identified in the dynamic stall development based on the shear layer evolution. In the first stage, the flow detaches from the trailing edge…
Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation
in Ocean Engineering, 169:370–378, 2018 This work presents a wind tunnel experimental study on the effect of the leading edge flapping on the aerodynamic performance of a spinnaker. Four J80-class spinnaker models, combining two different assembling structures (panel layout) and two different sail materials are tested at various wind speeds and wind angles in a…
Critical evolution of leading edge suction during dynamic stall
in Journal of Physics: Conference Series, 1037:022017, 2018 Dynamic stall dominates the aerodynamic performance, the robustness, and the wake dynamics of vertical axis wind turbines. To better assess the dynamic stall onset and its associated unsteady effects, this paper analyzes experimentally the evolution of the leading edge suction vector on a sinusoidally pitching airfoil based…