A Levelset-Based Sharp-Interface Modified Ghost Fluid Method for High-Speed Multiphase Flows and Multi-Material Hypervelocity Impact

2020 ◽  
pp. 187-226
Author(s):  
Pratik Das ◽  
Nirmal K. Rai ◽  
H. S. Udaykumar
Keyword(s):  
High Speed ◽  
Multiphase Flows ◽  
Hypervelocity Impact ◽  
Sharp Interface ◽  
Ghost Fluid Method ◽  
Modified Ghost Fluid Method

scholarly journals Spatially extended FCS for visualizing and quantifying high-speed multiphase flows in microchannels

2007 ◽  
Vol 15 (10) ◽  
pp. 6528 ◽  
Author(s):  
Sara M. Hashmi ◽  
Michael Loewenberg ◽  
Eric R. Dufresne
Keyword(s):  
High Speed ◽  
Multiphase Flows ◽  
Spatially Extended

Aluminum Shield Under Hypervelocity Impact of Mylar Flyer

2008 ◽  
Author(s):  
J. Zhao ◽  
F. Tan ◽  
C. Liu ◽  
C. Sun
Keyword(s):  
High Speed ◽  
Hypervelocity Impact ◽  
Space Environment ◽  
Lateral Expansion ◽  
Near Earth Space ◽  
The Third ◽  
Naturally Occurring ◽  
Debris Cloud ◽  
The Impact ◽  
Different Thickness

The near-earth space environment is cluttered with man-made debris and naturally occurring meteoroids, which is a big menace to the safety of satellites and spacecrafts. This paper is addressed on the failure response of aluminum shields under hypervelocity impact of milligrame level flyer. A compacted electric gun is employed to accelerate a mylar flyer up to 10 km/s. Failure response of Ly12 aluminum shields with different thickness and layers impacted by mylar flyer with different velocities is under investigation. The spallation is observed in the rear free surface of 4 mm thick monolithic aluminum shield, and its fracture mechanism changes from plastic to brittle when loading pressure is above 13 GPa. A perforation with a diameter 8 mm in the impacted area of the 4mm thick Ly12 shield is observed after which is impacted by 0.1 mm thick mylar flyer 8mm in diameter with velocity 8.2 km/s. When three layers of shields are impacted, the debris clouds (DC) are observed in the first and the second spaces respectively during the impact process by high speed camera, and its leftover can be observed on the surface of the third plate. The shape of the first debris cloud head is a little flat, and its speed of lateral expansion is very slow, which is different from those impacted by spherical projectile, and its formation mechanics mainly attributes to multi-spallations based on the analysis of simulation.

An Experimental Study of High-Velocity Impact on Aluminum Foam Composite Shield Structure

2013 ◽  
Vol 690-693 ◽  
pp. 20-24
Author(s):  
Qing Zhen Li ◽  
Zhong Hua Du ◽  
Kang Kang Wang
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Aluminum Foam ◽  
Space Debris ◽  
Hypervelocity Impact ◽  
Protective Effects ◽  
High Velocity Impact ◽  
Protective Structure ◽  
Velocity Impact ◽  
Foam Composite

To study spacecraft shield structure against hypervelocity impact of space debris and its protective performances, 25mm ballistic gun launching 12.7mm cylindrical debris is selected against Aluminum foam composite structure at high speed. Based on the experimental results and analyze the effects of Aluminum foam protective structure with different combinations, the result is that protective effects with Aluminum foam in front of glass fiber is better.

Computations of the Compressible Multiphase Flow Over the Cavitating High-Speed Torpedo

2003 ◽  
Vol 125 (3) ◽  
pp. 459-468 ◽  
Author(s):  
F. M. Owis ◽  
Ali H. Nayfeh
Keyword(s):  
High Speed ◽  
Multiphase Flows ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Multiphase System ◽  
System Of Equations ◽  
Cavitating Flows ◽  
Navier Stokes Equations ◽  
Compressible Multiphase Flow ◽  
Speed Flow

For high-speed cavitating flows, compressibility becomes significant in the liquid phase as well as in the vapor phase. In addition, the compressible energy equation is required for studying the effects of the propulsive jet on the cavity. Therefore, a numerical method is developed to compute cavitating flows over high-speed torpedoes using the full unsteady compressible Navier-Stokes equations. The multiphase system of equations is preconditioned for low-speed flow computations. Using the mass fraction form, we derive an eigensystem for both the conditioned and the nonconditioned system of equations. This eigensystem provides stability for the numerical discretization of the convective flux and increases the convergence rate. This method can be used to compute single as well as multiphase flows. The governing equations are discretized on a structured grid using an upwind flux difference scheme with flux limits. Single as well as multiphase flows are computed over a cavitating torpedo. The results indicate that the preconditioned system of equations converges rapidly to the required solution at very low speeds. The theoretical results are in good agreement with the measurements.

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