Aerodynamic Heating of a Hypersonic Projectile with Forward-Facing Ellipsoid Cavity at Nose

Yadav, Rajesh; Güven, Uğur

doi:10.2514/1.a32605

Cited by 28 publications

(4 citation statements)

References 11 publications

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“…A separate study by Engblom and Goldstein suggested that shallow cavities produce less heating at the base of the cavity than a deep cavity, but they produce higher heating at the edge of a sharp lip [7]. A recent computational study by Yadav and Guven [8] showed similar results for ellipsoid forward-facing cavities. Thus, the best design for the reduction of heat flux in a forward-facing cavity is still an open issue.…”

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confidence: 89%

Measurements of Resonance in a Forward-Facing Cavity at Mach Six

Chou

Schneider

2015

Journal of Spacecraft and Rockets

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An experimental study of the resonance of a cylindrical forward-facing cavity was conducted in a Mach 6 quiet-flow wind tunnel. The diameter of this cavity was fixed and the depth was varied in order to find the critical depth at which the cavity resonance became self-sustained. At Mach 6, this critical depth was 1.2 diameters deep, regardless of the freestream noise levels. For cavities deeper than 1.2 diameters, measurements of root-mean-square pressure fluctuations were orders of magnitude larger than those in shallower cavities. In quiet flow, this increase was about 2.5 orders of magnitude. In noisy flow, this increase was only about one order of magnitude. However, the magnitude of the pressure fluctuations within deep cavities was about the same in quiet flow as it was in noisy flow. The damping characteristics of a shallow cavity (depth less than 1.2 diameters) were also studied by observing the cavity response to a freestream laser-generated perturbation. The perturbation convects with the flow and interacts with the model's flowfield, causing pressure fluctuations in the forward-facing cavity. These pressure fluctuations damp exponentially in shallow cavities. The damping characteristics of such cavities appear to be related to the nondimensional cavity depth, regardless of stagnation pressure, stagnation temperature, and Mach number.

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confidence: 89%

Measurements of Resonance in a Forward-Facing Cavity at Mach Six

Chou

Schneider

2015

Journal of Spacecraft and Rockets

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“…Unsteady aerodynamics which is associated with the free flight for finned projectiles at supersonic speed by CFD means that was computed by Sahu and it contains advanced time-accurate Navier Stokes technique [15]. Some numerical experiments were carried out using common CFD codes to analyze aerodynamic heating of a hypersonic projectile by Yadav [16]. The remaining gaps in computational fluid dynamics (CFD) technology with an emphasis on hypersonic flow modeling was evaluated by Maicke et al, [17].…”

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confidence: 99%

Aerodynamic Performance Enhancement of Electromagnetic Gun Projectile Using Numerical Techniques

Rahman

Srinivas

2021

ARFMTS

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The unique study named aerodynamic performance enhancement of electromagnetic (EM) gun Projectile using numerical techniques is adopted to determine the better understanding of its aerodynamic characteristics. The earlier studies on EM gun projectile could explore its aerodynamic stability during flight whereas this unique research explains the enhancement of aerodynamic performance of EM gun projectile using numerical techniques. By using the Navier-Stokes numerical approach for a steady-state compressible flow, the Computational Fluid Dynamics (CFD) simulation of density, pressure, and temperature flow contours of the EM gun projectile flow field at different Mach number- 5 to 10 with an increment of 0.5 at zero angle of attack (AOA) have been analyzed. The results show an excellent agreement for the Mach numbers 5, 6, and 7. Moreover, to ensure accurate knowledge of the aerodynamic performance of EM gun projectile the numerical test is conducted several times using different turbulence models and differing the grid element sizes for Mach number 7. The results prove that at hypersonic speed the EM gun projectile performs in a much better way at Mach number 7. This best performance is analyzed by using the Spalart Allmaras (SA) turbulence model for grid size 5.4169e-03m. This work will help the researchers to do further improvements in EM gun projectile aerodynamic behaviors and also can be useful for military purposes.

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“…Hypersonic vehicles such as hypervelocity projectiles, re-entry vehicles and hypersonic aircraft are designed to withstand severe heat loads. A proposed heat transfer reduction mechanism is to locate a forward-facing cavity at the nose tip [1][2][3][4][5]. It was reported that the heat flux at the cavity base could be as little as 2 to 10 times less than the stagnation point of a conventional convex hemispherical tip [6].…”

Section: Introductionmentioning

confidence: 99%

Prediction of Shock-Standoff Distance and Entropy Distribution for Forward-Facing Cavity

Wang¹

2018

IJASS

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Experiments are performed on a cylinder with a forward-facing cavity at M ∞ = 10 in the FD-14A shock tunnel. The shock-standoff distance and oscillation characteristics are recorded by a high-speed movie, and the dynamic pressure transducer is used to capture the unsteady signal of cavity base. Based on experimental and numerical results, a prediction method for estimating the shock-standoff distance is proposed. Results of shock-standoff distance and oscillation frequency are obtained for experiments in the shock tunnel. The predicted oscillation frequency is in accordance with experimental results. Furthermore, the relation of shock shape and the entropy increase are combined to obtain the characteristics of entropy distribution. As the shock-shape of flat-nosed cylinders is more liable to be influenced than blunt-nosed cylinders with increasing Mach number, the location of the extreme value moves to the surface as the Mach number increases for flat-nosed cylinders, while it remains the identical location for blunt-nosed cylinders.

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Aerodynamic Heating of a Hypersonic Projectile with Forward-Facing Ellipsoid Cavity at Nose

Cited by 28 publications

References 11 publications

Measurements of Resonance in a Forward-Facing Cavity at Mach Six

Measurements of Resonance in a Forward-Facing Cavity at Mach Six

Aerodynamic Performance Enhancement of Electromagnetic Gun Projectile Using Numerical Techniques

Prediction of Shock-Standoff Distance and Entropy Distribution for Forward-Facing Cavity

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