arXiv subjects

Kevin Gouder

Publications and source records attributed to Kevin Gouder.

3 recordsLinked to original sources

arXiv2026

Set-up and Characterisation of Atmospheric Boundary Layers in the 10'x5' Wind Tunnel

The Atmospheric Boundary Layer (ABL) plays a critical role in influencing objects exposed to atmospheric conditions, making its study crucial. Due to the high cost of real-world testing, this thesis focuses on replicating marine ABLs in a wind tunnel environment. Two profiles were developed: one that served as a framework for establishing commonality among the various international wind engineering standards ('Profile 1'), and a second profile, which is more suitable for modelling the inflow to wind farms in the English Channel and the North Sea ('Profile 2'). The ABLs were generated using Irwin spires without floor roughness elements, and the flow characteristics were measured using Laser Doppler Anemometry (LDA) and a multi-hole probe (MHP). MHP showed a reasonably high accuracy when compared to LDA, with less than 1% deviation in the streamwise velocity and under 5% standard deviation in the streamwise, spanwise, and wall-normal velocity components. The profiles achieved good agreement with target metrics such as normalised velocity and turbulence intensity. Spanwise uniformity and spectral analysis confirmed the robustness of the simulation across varying inflow velocities. Overall, Irwin spires proved to be a cost-effective and reliable method for simulating marine ABLs, offering valuable insights for optimising offshore wind energy systems.

physics.flu-dyn↗

arXiv2026

Wind-turbine wake effects on the rate of accumulation of fatigue damage in overhead conductors

Guidance relating to the safe distance within which overhead conductors (OHCs) should not be built with respect to a wind turbine, and vice versa, varies from country to country. In the United Kingdom the recommendation is that OHCs are not installed within three rotor diameters (3D) of wind turbines due to concerns over wake-induced fatigue. To assess the physical basis for this recommendation, wind-tunnel experiments were conducted using a scaled wind turbine placed upstream of an instrumented conductor, in conditions representative of forested terrain. The conductor was equipped with distributed fibre-optic strain sensing based on Rayleigh backscattering, providing spatially resolved measurements at 2.6 mm resolution. Three conductor heights and four turbine-conductor spacings were tested, together with a no-turbine baseline, while maintaining a constant incident wind speed of 7 m/s. The results identify a critical region near the clamp where mean strain is maximised. Neither mean nor fluctuating strain at this location increased substantially due to the presence of the turbine wake. Strain fluctuations were dominated by aeolian vibration, with the wake increasing vibration amplitude whilst reducing its characteristic frequency. Rainflow counting fatigue analysis shows that damage accumulation depends strongly on conductor height. While fatigue damage rates increase when the conductor is fully immersed in the wake, reduced damage rates are observed for lower heights and closer spacings. These results suggest that, under forested atmospheric conditions, conductor-turbine separations smaller than the current 3D guidance may be feasible provided the conductor is not fully immersed in the turbine wake.

physics.flu-dyn↗

arXiv2019

Spectral/hp element simulation of flow past a Formula One front wing: validation against experiments

Emerging commercial and academic tools are regularly being applied to the design of road and race cars, but there currently are no well-established benchmark cases to study the aerodynamics of race car wings in ground effect. In this paper we propose a new test case, with a relatively complex geometry, supported by the availability of CAD model and experimental results. We refer to the test case as the Imperial Front Wing, originally based on the front wing and endplate design of the McLaren 17D race car. A comparison of different resolutions of a high fidelity spectral/hp element simulation using under-resolved DNS/implicit LES approach with fourth and fifth polynomial order is presented. The results demonstrate good correlation to both the wall-bounded streaklines obtained by oil flow visualization and experimental PIV results, correctly predicting key characteristics of the time-averaged flow structures, namely intensity, contours and locations. This study highlights the resolution requirements in capturing salient flow features arising from this type of challenging geometry, providing an interesting test case for both traditional and emerging high-fidelity simulations.

physics.flu-dyn↗