Implications of scale effect for the prediction of high angle of attack aerodynamics

On Subscale Flight Testing : Applications in Aircraft Conceptual Design

“…Fortunately, in many cases the impact of these two parameters can be studied independently, considering that Reynolds number effects are typically negligible outside the boundary-layer region near the body surface [55,58,59,60]. Experimental studies such as [61] and [62] support this assumption by showing a clear distinction between the effect of Mach number and those caused by Reynolds number variations.…”

“…In fact, despite the inevitable exposure to undesirable scale effects, only a very small fraction of experimental aerodynamics testing is conducted at representative, full-scale Reynolds and Mach numbers due to the high cost involved and the few operative ground facilities with the necessary capabilities [60]. It is therefore essential to understand and quantify the influence of scale effects in order to apply the necessary corrections; a complex task that often requires not only extensive knowledge and experience but also complementary data from other tests or methodologies [63].…”

“…Flow aspects such as the boundary layer are very sensitive to variations in Reynolds number [60]. While it is clear that this parameter plays a significant role, scale effects of relevance for aerodynamics are not limited to a single Reynolds number problem.…”

“…Aerospace manufacturers often base Reynolds number corrections on empirical databases accumulated from years of experience with different programmes; a highly valuable information which usually remains company proprietary. This method produces reliable estimations for conventional or well-understood configurations but introduces a considerable uncertainty in cases where the configuration is not well understood or the flow is highly complex [2,55,60]. Nowadays, complementary analysis tools such as Computational Fluid Dynamics (CFD) are also used to estimate scale effects in experimental data.…”

Recent progress on the study of asymmetric vortex flow over slender bodies

“…In order to implement these high performances the aircraft often fly at high angles of attack, even at a post stall state. Therefore the subject on high angle of attack aerodynamics has been studied extensively and a large number of experimental and computational investigations in this field have been reported in the literature [1][2][3][4][5][6][7][8][9][10][11][12][13][14].…”