Experimental and numerical aspects of simulating unsteady flows around the X-31 configuration

Schütte, Andreas; Rein, Martin; Höhler, Gebhard

doi:10.1243/09544100jaero387

Cited by 14 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several publications [17,21,35] of the author are used for the validation of the numerical method and grid generation approach and provide the validation for the RANS solver DLR TAU to justify the present numerical approach.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Investigations of Vortical Flow on Swept Wings with Round Leading Edges

Schütte

2017

Journal of Aircraft

View full text Add to dashboard Cite

The present work is investigating the vortex-dominated flow physics as well as the aerodynamic behavior of swept wing configurations with round leading edges. The research is based on numerical simulations using the computational fluid dynamics method DLR TAU. The target configurations are swept wings of constant aspect ratio, variable leading-edge contours, and leading-edge sweep angles. The work deals with the onset of the vortical flow at the leading edge for constant and variable leading-edge nose radii, the influence of the angle of attack, the leading-edge sweep, and the onflow Mach number. Furthermore, the aerodynamic behavior is analyzed and assessed, as well as the specific flow physics in the vicinity of the vortical flow separation at round leading edges. The objective of the present work is to provide a contribution for the design and assessment of the physical characteristics of swept wing configurations. Furthermore, sensitivities will be given for the design process. In addition, the current investigation provides a deeper understanding of the separation onset process and the flow physics of swept wing configurations with round leading edges. Nomenclaturewing reference length, depth of the wing, m M ∞ = onflow Mach number, equal to a∕U ∞ p = pressure, N∕m 2 q ∞ = onflow dynamic pressure, N∕m 2 Re ∞ = Reynolds number, equal to U ∞ · c ref ∕ν r = radius at nose of the profile, m r N = nondimensional leading-edge contour radius, equal to r∕c ref s = wing semispan, m T = temperature, K t = time, s U ∞ = onflow velocity, m∕s u = local velocity within the flowfield, m∕s x, y, z = Cartesian coordinates, m y W = initial wall distance, distance of first grid point from wing surface, m y = nondimensional value to assess resolution of boundary-layer wall unit, equal to τ W ∕ρ p · y W ∕ν α = angle of attack, deg β = angle of sideslip, deg γ = circulation Δt = discrete time step, s Δx = discrete step in space, m μ = dynamic viscosity, Ns∕m 2 ν = kinematic viscosity, m 2 ∕s ρ = density, kg∕m 3 τ W = wall friction, N∕m 2 φ = wing sweep, deg k∂ρ∕∂tk = density residual, kg∕m 3 s Subscripts le = leading edge r = root ref = reference parameter ∞ = onflow condition

show abstract

Section: Discussionmentioning

confidence: 99%

“…The experimental results are documented by Rein et al [18]. The numerical results using TAU are described in detail in Schütte et al [19][20][21][22][23]. Additional results are given by Boelens [24] and Jirasek and Cummings [25].…”

mentioning

confidence: 99%

Numerical Investigations of Vortical Flow on Swept Wings with Round Leading Edges

Schütte

2017

Journal of Aircraft

View full text Add to dashboard Cite

show abstract

“…Most of the applications of the Tau-Code in this paper are based on these experiences. Among others, these computational results include work on the VFE-2 [9] configuration, the X-31 [25][26][27], and the F-16 Cranked Arrow Wing Aerodynamics Project International (CAWAPI) [28].…”

Section: A Computational Fluid Dynamics Solver Taumentioning

confidence: 99%

Flow Physics Analyses of a Generic Unmanned Combat Aerial Vehicle Configuration

Schütte

Hummel

Hitzel³

2012

Journal of Aircraft

View full text Add to dashboard Cite

Within the NATO Research and Technology Organisation Applied Vehicle Technology (AVT)-161 task group, titled "Assessment of Stability and Control Predictions for NATO Air and Sea Vehicles," a 53° swept and twisted lambda wing with rounded leading edges is considered. In a first step, the symmetric flow conditions are analyzed in this paper in order to understand the corresponding flow physics. Experiments by the task group are used to develop proper numerical simulation tools for further applications in the design process of unmanned combat aerial vehicles as a part of future air-combat systems. The philosophy of the configuration under consideration is explained. The vortical flowfield is simulated using the DLR, German Aerospace Center TAU-Code applied with different turbulence models on various computational grids. Finally, a best practice is evaluated for medium and large angles of attack. A combination of these numerical results and experimental data lead to a proper understanding of the complex flow structure. Furthermore, this paper addresses the necessity for the predictability and understanding of controlled and uncontrolled flow separation, together with the interaction of the corresponding vortex systems in order to estimate stability and control issues for the entire flight envelope. NomenclatureA = attachment line C¿ = lift coefficient; ¿/(^oo • S) Cl = rolling moment coefficient; l/(q^ • S • c^f) Clß = rolling moment due to sideslip; 9C,/9Ĉ " = pitching moment coefficient (noseup positive); c" = yawing moment coefficient; «/(í/^, • 5-Cref) c"ß = yawing moment due to sideslip; 9C"/9Ĉ p = pressure coefficient; {p -/'oo)/9oo Cf = root chord length of the model cVef = reference length / = frequency /j = moment of inertia around x I y = moment of inertia around y k = reduced frequency; 27r • / • c,^f/VM = Mach number 9tx) = dynamic pressure coefficient; p^ • V^/2 R = Reynolds number; V^ • c^f/v S = reference area 5 = separation line s = half-span Presented a.s

show abstract

“…Many research efforts have been reported in the literature to estimate the parameter deviation [19]. In practice, a suitable aerodynamic design of the interceptor that can adaptively respond to the abrupt changes in direction and attitude during flight needs to be incorporated [20]. The OGL in this research is obtained based on linear approximations of the motion equation.…”

Section: Miscellaneousmentioning

confidence: 99%

Optimal guidance law and control of impact angle for the kinetic kill vehicle

Cai

2011

Proceedings of the Institution of Mechanical Engineers, Part G:

View full text Add to dashboard Cite

In order to increase the effectiveness of the kinetic kill vehicle (KKV), control of impact angle is required in the terminal engagement. The purpose of this research is to achieve an optimal guidance law (OGL) with a specified impact angle as well as zero terminal miss distance. An energy OGL based on a simplified mathematical model to achieve the performance of the KKV is presented. Numerical simulation is used to analyse the performance of the guidance law. The results show that the proposed law has higher accuracy, larger capture zone, and lesser energy consumption than the conventional proportional navigation guidance laws. Moreover, the influence of the initial heading angle is discussed, and the capture zone of both the initial heading angle and the terminal impact angle are given.

show abstract

Experimental and numerical aspects of simulating unsteady flows around the X-31 configuration

Cited by 14 publications

References 9 publications

Numerical Investigations of Vortical Flow on Swept Wings with Round Leading Edges

Numerical Investigations of Vortical Flow on Swept Wings with Round Leading Edges

Flow Physics Analyses of a Generic Unmanned Combat Aerial Vehicle Configuration

Optimal guidance law and control of impact angle for the kinetic kill vehicle

Contact Info

Product

Resources

About