James DeSpirito’s research while affiliated with University of Sharjah and other places

... There are no universal criteria such that one can claim that a numerical solver has been "validated"; validation can only be established for particular problems where reliable data already exists [5]. As an example, the NATO Science & Technology Organization (STO) efforts AVT-316 and AVT-390 [6][7][8][9] were organized to assess the capability of CFD solvers to predict an experimentally-demonstrated break in rolling moment for total angles of incidence beyond 16 • . The transonic regime and high-angle of incidence create conditions for several complex and unsteady phenomena: shock-induced separation at the nose, shock boundary layer interactions over the wings, shock-vortex interactions from the leading-edge vortices, and largely separated regions over the wings at higher angles. ...

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DLR LK6E2 Missile Airframe Validation Study Using Wall-Modeled Large Eddy Simulations

... There are no universal criteria such that one can claim that a numerical solver has been "validated"; validation can only be established for particular problems where reliable data already exists [5]. As an example, the NATO Science & Technology Organization (STO) efforts AVT-316 and AVT-390 [6][7][8][9] were organized to assess the capability of CFD solvers to predict an experimentally-demonstrated break in rolling moment for total angles of incidence beyond 16 • . The transonic regime and high-angle of incidence create conditions for several complex and unsteady phenomena: shock-induced separation at the nose, shock boundary layer interactions over the wings, shock-vortex interactions from the leading-edge vortices, and largely separated regions over the wings at higher angles. ...

Reference:

DLR LK6E2 Missile Airframe Validation Study Using Wall-Modeled Large Eddy Simulations

... In terms of the body diameter ( =105mm), the projectile is 10 in length with a 3 long von Kármán ogive nosecone that has a 0.1 blunt nose radius. The aerodynamics of this generic projectile, without emphasis on the aft-region, have been well characterized experimentally and computationally [30,31], results from which will serve as validation for the present simulations. ...

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Effect of Fins on the Mean Base Flow of a Generic Supersonic Projectile

... The Missile Facet was established to (i) Assess the current capabilities of CFD to predict missile aerodynamic characteristics for flows containing multiple vortex interactions; (ii) Share and seek to learn from comparable experience of applying CFD to other classe s of NATO vehicles (combat aircraft, in particular); and (iii) Consolidate lessons learned and an y attendant future requirements [11]. This paper is one of a series being presented at this conference to provide a technical overview of the activities and accomplishments of the AVT-316 Missile Facet [12][13][14][15][16][17][18][19][20][21][22]. The work is still ongoing: a final output, constituting a more detailed and consolidated technical record, will be published by NATO STO towards the end of 2022. ...

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The Influence of the Computational Mesh on the Prediction of Vortex Interactions about a Generic Missile Airframe

... LK6E2 was one of the research test cases developed to investigate vortex interactions on highly maneuverable transonic missiles. The initial collaborative analysis of the test case was published during special sessions at AIAA 2022 SciTech Conference [6,7]. It was shown that the flow solver and the turbulence model greatly impact the prediction of the flow field and aerodynamic coefficients of these missiles at high flow angles and transonic speeds. ...

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Towards Accurate Vortex Separation Simulations with RANS Using Improved k-kL Turbulence Model

... LK6E2 was one of the research test cases developed to investigate vortex interactions on highly maneuverable transonic missiles. The initial collaborative analysis of the test case was published during special sessions at AIAA 2022 SciTech Conference [6,7]. It was shown that the flow solver and the turbulence model greatly impact the prediction of the flow field and aerodynamic coefficients of these missiles at high flow angles and transonic speeds. ...

Reference:

Towards Accurate Vortex Separation Simulations with RANS Using Improved k-kL Turbulence Model

... The prediction of vortex flows is extremely sensitive to domain resolution and numerical settings [5,29,30]. ...

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Towards Accurate Vortex Separation Simulations with RANS Using Improved k-kL Turbulence Model

... A similar work has been carried of using the NASA FUN3D code with the rene library. 18 The volume for the nal Mach adaptive mesh created with the Mach and distance sensors is shown in Figure 15, along with a horizontal y = 0 slice for both norms. Additionally, the complex shock and vortical structure are shown in Figure 15 with density contour from a slice where conical shocks are produced by the nose, leading edge of the wing, trailing edge of the wing, and n. Figure 16a and 16b and show the section through the n mid-chord of missile. ...

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Correction: HEMLAB Algorithm Applied to HIOCFD Delta Wing and OTC1 Missile

... The prediction of vortex flows is extremely sensitive to domain resolution and numerical settings [5,29,30]. ...

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Towards Accurate Vortex Separation Simulations with RANS Using Improved k-kL Turbulence Model

... The turbulence models estimate excessive turbulent viscosity and, therefore, tend to dissipate the vortex rapidly. Therefore, the dissipation characteristics of the numerical model are also important [5,6,31]. ...

Reference:

Towards Accurate Vortex Separation Simulations with RANS Using Improved k-kL Turbulence Model