Objectives, approach, and scope for the AVT-183 diamond-wing investigations

Miau

et al. 2023

JFST

The vortex system on the SACCON model is studied under low Reynolds number by using the flow visualization technique and the surface pressure testing measurement in a low-speed water channel and a wind tunnel, respectively. A main topic is discussed below. The blunt leading-edge section on this SACCON model induces various flow phenomena under different angles of attack. The attached flow appearing around the upstream leading-edge region at a low angle of attack induces different flow phenomena downstream, so does the branched vortices appearing near the trailing-edge. Although this attached flow is vanished at higher angle of attack, the stability of forming an outboard vortex can be shown in the results of pressure coefficients as a function of an angle of attack. Moreover, how the blunt leading-edge contour on SACCON model and other models affecting flow field can be compared with the findings given in the previous studies. The models with only blunt leadingedge contour can prompt an outboard vortex and an inner vortex, compared to the flow fields on the models with spanwise-varying leading-edge contours. This inner vortex is formed due to the attached flow inboard passing downstream and being affected by the outboard vortex. However, this attached flow is different from the attached flow observed on SACCON model. Therefore, flow phenomena occurring on different blunt leading-edge models can be differentiated.

Section: Introductionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Blunt leading-edge effect on spanwise-varying leading-edge contours of an UCAV configuration

Miau

et al. 2023

JFST

14th WCCM-ECCOMAS Congress

“…The AVT-183 test case consists of a 53°swept diamond wing and it has been the target of the investigation performed in the NATO-STO AVT-183 task group [17,18]. The geometry has a rounded leading-edge shape which causes partially developed vortex stages in the range of smaller angles of attack.…”

Section: Avt-183 Configurationmentioning

confidence: 99%

Turbulence Model Extension for Vortex Dominated Flows and Optimization with Experimental Data

Moioli¹,

Breitsamter²,

Sørensen³

2021

“…Because the investigations target only symmetric flow conditions, a half model has been developed and manufactured ( Figure 1) [2,14]. The model root chord measures c r = 1.200 m and its resulting half span is s = 0.657 m. The interaction of the diamond wing flow and the test-section boundary layer is eliminated by a péniche with a height of h pen = 0.090 m. Geometric reference values for calculating force coefficients are the reference wing area S re f = 0.394 m 2 and the mean aerodynamic chord l µ = 0.800 m. The maximum relative test section blockage of 4.8% is reached at the highest angle of attack of α = 32 • .…”

Section: Wind Tunnel Modelmentioning

confidence: 99%

“…The understanding of the complex flow field for low/moderately swept wings (leading-edge sweep angles in the range of ϕ = 45 • -55 • ) is essential for designing modern low-radar signature uninhabited aerial vehicles (UAV) [1]. To study the flow separation onset on corresponding blunt leading edges the North Atlantic Treaty Organization's (NATO) Applied Vehicle Technology Group AVT-183 designed a generic diamond wing geometry with a rounded leading edge [2]. The flow field around this wing constitutes a vortex system that differs to some extent from "classical" leading-edge vortex separation from a sharp edge of a slender swept wing (sweep angle ϕ > 60 • ), for which extensive investigations have been conducted [3].…”

Section: Introductionmentioning

confidence: 99%

Leading-Edge Roughness Affecting Diamond-Wing Aerodynamic Characteristics

et al. 2018

Self Cite

Diamond wing configurations for low signature vehicles have been studied in recent years. Yet, despite numerous research on highly swept, sharp edged wings, little research on aerodynamics of semi-slender wings with blunt leading-edges exists. This paper reports on the stall characteristics of the AVT-183 diamond wing configuration with variation of leading-edge roughness size and Reynolds number. Wind tunnel testing applying force and surface pressure measurements are conducted and the results presented and analysed. For the investigated Reynolds number range of 2.1 × 10 6 ≤ R e ≤ 2.7 × 10 6 there is no significant influence on the aerodynamic coefficients. However, leading-edge roughness height influences the vortex separation location. Trip dots produced the most downstream located vortex separation onset. Increasing the roughness size shifts the separation onset upstream. Prior to stall, global aerodynamic coefficients are little influenced by leading-edge roughness. In contrast, maximum lift and maximum angle of attack is reduced with increasing disturbance height. Surface pressure fluctuations show dominant broadband frequency peaks, distinctive for moderate sweep vortex breakdown. The experimental work presented here provides insights into the aerodynamic characteristics of diamond wings in a wide parameter space including a relevant angle of attack range up to post-stall.