Mechanical vs. phenomenological formulations to determine mean aerodynamic drag from stereo-PIV wake measurements

Abstract

The present work compares two different drag breakdown methods based on the wake survey of a finite size wing. The traditionnal control volume approach based on a global balance of momentum (cf. for instance [17]) is considered, and compared to the phenomenological drag breakdown formulation put forward by Méheut & Bailly [14] within the aerodynamic context. Both formulations require information on the velocity field, but also the static or stagnation pressure in the wake plane of the model of interest. In this paper, we focus on computing the results based on velocity data exclusively, acquired by stereo-PIV. These two methods are benchmarked experimentally on the wake of a SACCON [19] model, that has been measured in one of ONERA's wind-tunnels, and their performance is evaluated by comparing their results to direct force balance measurements. It is shown that while both methods perform similarly, with drag predictions lying within 10% of the balance measurements, the control volume approach systematically underestimates the total drag. This behavior is attributed to the PIV-reconstructed pressure field failing in capturing the high depression occurring in the cores of the

An Overview of ONERA Research Activities Related to Drag Analysis and Breakdown

“…The preliminary results shown here are promising, and suggest that stereo-PIV may indeed be a pertinent option when determining all far-field drag components acting on a model, within an industrial context [65]. First, the dramatic time savings introduced by this method makes it viable to measure a large number of samples.…”