scholarly journals Cratering for Impact of Hypervelocity Projectiles into Granite Targets within a Velocity Range of 1.91–3.99 km/s: Experiments and Analysis

2020 ◽  
Vol 10 (4) ◽  
pp. 1393
Author(s):  
Xiaofeng Wang ◽  
Jingbo Liu ◽  
Biao Wu ◽  
Defeng Kong ◽  
Jiarong Huang ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Scaling Law ◽  
Density Ratio ◽  
Hypervelocity Impact ◽  
Experimental Results ◽  
Tungsten Alloy ◽  
Regression Equations ◽  
Velocity Range ◽  
Predicted Values ◽  
The Impact

To understand and analyze crater damage of rocks under hypervelocity impact, the hypervelocity impact cratering of 15 shots of hemispherical-nosed cylindrical projectiles into granite targets was studied within the impact velocity range of 1.91–3.99 km/s. The mass of each projectile was 40 g, and the length–diameter ratio was 2. Three types of metal material were adopted for the projectiles, including titanium alloy with a density of 4.44 g/cm3, steel alloy with a density of 7.81 g/cm3, and tungsten alloy with a density of 17.78 g/cm3. The projectile–target density ratio (ρp/ρt) ranged from 1.71 to 6.86. The depth–diameter ratios (H/D) of the craters yielded from the experiments were between 0.14 and 0.24. The effects of ρp/ρt and the impact velocity on the morphologies of the crater were evaluated. According to the experimental results, H/D of craters is negatively correlated with the impact velocity, whereas the correlation between H/D and ρp/ρt is weak positive. The crater parameters were expressed as power law relations of impact parameters by using scaling law analysis. The multiple regression analysis was utilized to obtain the coefficients and the exponents of the relation equations. The predicted values of the regression equations were close to the experimental results.

Hot Streaks and Phantom Cooling in a Turbine Rotor Passage: Part 1—Separate Effects

1993 ◽  
Vol 115 (4) ◽  
pp. 657-666 ◽  
Author(s):  
R. J. Roback ◽  
R. P. Dring
Keyword(s):  
Free Stream ◽  
Density Ratio ◽  
Turbine Rotor ◽  
Experimental Results ◽  
Airfoil Surface ◽  
Stream Density ◽  
Controlling Variables ◽  
Hot Streak ◽  
Cooling Air ◽  
The Impact

This paper presents experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. Results are shown that quantify the impact of (1) a nonuniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and (2) cooling air discharged from the trailing edge of the upstream stator. In Part 1 of this paper, experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free-stream density ratio, streak injection location, and coolant-to-free-stream density and velocity ratios. In Part 2 of this paper, experimental results are shown for the combined effects of hot streak and stator coolant. An analytical model is also presented to correlate the experimental results.

Hot Streaks and Phantom Cooling in a Turbine Rotor Passage: Part 2—Combined Effects and Analytical Modeling

1993 ◽  
Vol 115 (4) ◽  
pp. 667-674 ◽  
Author(s):  
R. J. Roback ◽  
R. P. Dring
Keyword(s):  
Free Stream ◽  
Density Ratio ◽  
Turbine Rotor ◽  
Experimental Results ◽  
Combined Effects ◽  
Airfoil Surface ◽  
Stream Density ◽  
Hot Streak ◽  
Cooling Air ◽  
The Impact

This paper presents experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. In particular, results are shown that quantify the impact of (1) a nonuniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and (2) cooling air discharged from the trailing edge of the upstream stator. In Part 1 of this paper, experimental results were shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free-stream density ratio, streak injection location, and coolant-to-free-stream density and velocity ratios. In Part 2 of this paper, experimental results will be shown for the combined effects of hot streak and stator coolant on the adiabatic recovery temperature on the rotor. An analytical model is also developed to correlate the experimental results documented in Parts 1 and 2 of the paper.

scholarly journals Simulation of Fragmentation Characteristics of Projectile Jacket Made of Tungsten Alloy after Penetrating Metal Target Plate using SPH Method

2019 ◽  
Vol 69 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Chun Cheng ◽  
Zhonghua Du ◽  
Xi Chen ◽  
Lizhi Xu ◽  
Chengxin Du ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Maximum Tensile Stress ◽  
Calculation Model ◽  
Tungsten Alloy ◽  
Metal Target ◽  
Target Plate ◽  
Average Mass ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
The Impact

A smooth particle hydrodynamics (SPH) model was used to simulate the fragmentation process of the jacket during penetrator with lateral efficiency (PELE) penetrating the metal target plate to study the fragmentation characteristics of PELE jacket made of tungsten alloy. The validity of the SPH model was verified by experimental results. Then the SPH model was used to simulate the jacket fragmentation under different impact velocity and thickness of target plate. The influence of impact velocity and thickness of target plate on the jacket fragmentation was obtained by analysing the mass distribution and quantity distribution of the fragments formed by the jacket. The results show that the dynamic fragmentation of tungsten alloy can be simulated effectively using the SPH model, Johnson-Cook strength model, maximum tensile stress failure criterion and stochastic failure model. When the thickness of target plate is fixed, the greater the impact velocity, the greater the pressure produced by the projectile impacting the target plate; with the increase of impact velocity, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. When the impact velocity is constant, the greater the thickness of the target plate, the longer the pressure duration by the projectile impacting the target plate; with the increase of the thickness of target plate, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. The numerical calculation model and research method adopted in this paper can be used to study the impact fragmentation of solid materials effectively.

Numerical study of dynamic behavior of foams subjected to high- to hyper-velocity impact

2019 ◽  
Author(s):  
Xiaotian Zhang ◽  
Ruiqing Wang ◽  
Q.M. Li
Keyword(s):  
Dynamic Behavior ◽  
Impact Velocity ◽  
Foam Cell ◽  
Numerical Study ◽  
Failure Process ◽  
Failure Mechanisms ◽  
Hypervelocity Impact ◽  
Deformation And Failure ◽  
Set Up ◽  
The Impact

Abstract Hypervelocity tests and numerical studies have been reported in the literature for aluminum foam to show its potential applications in spacecraft shielding against space debris based on “shielding set-up”. Meanwhile the “forward impact” set-up has been widely reported in the literature to study the dynamic behavior of the foam materials in the range of low to intermediate impact velocities. This paper extends the forward impact to high- and hyper-velocity impacts to understand the dynamic deformation and failure mechanisms based on numerical simulation. The focused impact velocity range is from about 1km/s to 6km/s. The cell-based numerical model of the foam material is used along with the Smoothed Particle Hydrodynamics (SPH) method to simulate the deformation and the failure process. The failure of the foam materials in the range of intermediate to high impact velocities is related to the plastic yielding and crushing of the foam cell, while that in the hypervelocity impact regime is related to the cell material erosion. Dynamic effects in different impact velocity ranges also lead to shock and strain-rate effects. Understanding of the dependence of the deformation/failure mechanisms on the impact velocity helps to determine the application of foam materials in the relevant range of impact velocities.

scholarly journals Hot Streaks and Phantom Cooling in a Turbine Rotor Passage: Part 1 — Separate Effects

1992 ◽  
Author(s):  
Richard J. Roback ◽  
Robert P. Dring
Keyword(s):  
Free Stream ◽  
Density Ratio ◽  
Turbine Rotor ◽  
Experimental Results ◽  
Airfoil Surface ◽  
Stream Density ◽  
Controlling Variables ◽  
Hot Streak ◽  
Cooling Air ◽  
The Impact

This paper presents experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. Results are shown which quantify the impact of (1) a non-uniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and (2) cooling air discharged from the trailing edge of the upstream stator. In Part 1 of this paper, experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free stream density ratio, streak injection location and coolant-to-free stream density and velocity ratios. In Part 2 of this paper, experimental results are shown for the combined effects of hot streak and stator coolant. An analytic model is also presented to correlate the experimental results.

Experimental study of spreading characteristics of droplet impacting on canopy fabric surface

2017 ◽  
Vol 31 (34) ◽  
pp. 1750325 ◽  
Author(s):  
Han Cheng ◽  
Chao Qiu ◽  
Changchun Zhou ◽  
Xuebin Sun ◽  
Rui Yang
Keyword(s):  
Experimental Study ◽  
Kinetic Energy ◽  
Impact Velocity ◽  
Working Conditions ◽  
Experimental Results ◽  
Initial Kinetic Energy ◽  
Droplet Spreading ◽  
Visualization Technology ◽  
Fabric Surface ◽  
The Impact

A new experiment based on visualization technology is designed to study the spreading characteristics of droplet impacting on canopy fabric. The processes of droplet impacting on 66 type polyamide grid silk are captured. The experimental results show that the spreading characteristics are also affected by fabric pretension and fabric permeability. The pretension is favorable for the droplet to reach the final equilibrium stage. The impact velocity determines the initial kinetic energy and plays a major role in the droplet spreading. The fabric permeability determines the wettability and has different effects on spreading characteristics under different working conditions. In addition, the above factors can enhance the two competitive processes of spreading and imbibing at the same time. The spreading characteristics depend on which process is the dominant one.

An Examination of DOP Test of Ceramic Tile Subjected to Long Rod Penetration

2014 ◽  
Vol 566 ◽  
pp. 353-358
Author(s):  
Jian Ming Yuan ◽  
Geoffrey E.B. Tan
Keyword(s):  
Numerical Solution ◽  
Impact Velocity ◽  
Ceramic Tile ◽  
Tungsten Alloy ◽  
Ceramic Tiles ◽  
Depth Of Penetration ◽  
Ballistic Performance ◽  
Long Rod ◽  
Multilayered Materials ◽  
The Impact

Depth of penetration (DOP) test of ceramic tile subjected to long rod impact was analyzed by applying the Tate model. This paper investigated the influence of impact velocity and tile thickness on the ballistic performance measurement of the tested ceramic tiles. DOP test was simplified as an eroding rod penetrating a target composed of multilayered materials. Through applying the Tate model, the method of obtaining the numerical solution was proposed. For a constant impact velocity, it was found that the measured differential tile efficiency (DEF) was independent of the thickness of the ceramics tiles. But the measured DEF decreased as the impact velocity increased. These analytical conclusions were verified by the using of the results of DOP tests of SiC and Al2O3 tiles subjected to impact of long tungsten alloy rods at a nominal impact velocity of 1.3 km/s.

A New Formula for Predicting the Crater Size of a Target Plate Produced by Hypervelocity Impact

2019 ◽  
Vol 17 (01) ◽  
pp. 1844004 ◽  
Author(s):  
Z. L. Zhang ◽  
T. Ma ◽  
D. L. Feng ◽  
M. B. Liu
Keyword(s):  
Impact Velocity ◽  
Hypervelocity Impact ◽  
Model Parameters ◽  
Target Plate ◽  
Sph Method ◽  
Crater Size ◽  
Steady Stage ◽  
Kernel Gradient Correction ◽  
Simulation Results ◽  
The Impact

Hypervelocity impact (HVI) of materials is usually associated with large deformations of structures, big craters, phase transition of materials and scattered debris cloud. It is difficult to predict the size of damage caused by HVI while comprehensively considering all the influencing factors for both experimental and numerical approaches. In this paper, the HVI process is modeled by using the smoothed particle hydrodynamics (SPH) method with Kernel Gradient Correction (KGC) technique. The SPH method with KGC (SPH-KGC) has been demonstrated to have better accuracy and reliability for modeling the HVI problems in our recent work. In this paper, the SPH-KGC method is used to investigate the HVI of a sphere on a target plate. The sizes of the craters produced by HVI at different initial impact velocities are obtained, and the variation of the crater size over the impact velocity is studied. According to the present simulation results, a critical velocity is identified and the increase of the crater size versus the initial impact velocity can be divided into two stages, a varying stage and a steady stage. A new empirical formula is presented for predicting the crater size of the target plate produced by HVI. This formula comprehensively considers the influence of many model parameters, such as the densities of the materials of both the projectile and the target, the sound speed of the target material, the diameter of the projectile and the thickness of the target plate. The results obtained by the presented prediction formula agree well with the experimental observations as well as the present SPH simulation results.

Porous Barriers Efficiency Research under the Compact Elements High-Speed Loading (Part Two)

2020 ◽  
Vol 303 ◽  
pp. 1-7
Author(s):  
E.N. Kramshonkov ◽  
A.V. Krainov ◽  
Evgeny N. Pashkov
Keyword(s):  
Numerical Simulation ◽  
Impact Velocity ◽  
High Speed ◽  
Equal Mass ◽  
Tungsten Alloy ◽  
Shock Interaction ◽  
Initial Speed ◽  
Velocity Range ◽  
High Speed Impact ◽  
Porous Barriers

The paper discusses the results of the numerical simulation of high-speed impact effect of compact projectiles made of steel and tungsten alloy with steel obstacles of equal mass. The obstacles have different initial porosity of the material. Conducted the final evaluation of the penetration speed of the projectile depending on the porosity of the obstacle and the initial speed of the shock interaction. The initial impact velocity range from 1 to 16 [km/s]. The destruction, melting and evaporation of the interacting bodies are taken into account. The analysis of porosity influence evaluation of obstacles material revealed that the protective advantage of porous obstacles disclose at the higher impact velocities, greater than 1.5 [km/s] for steel strikers and 2 [km/s] for projectiles of tungsten alloy. The more impact velocity the more protective effect of porous obstacles.

Optimization of erosion wears of Al–Mg–Si–Cu–SiC composite produced by the PM method

2020 ◽  
Vol 39 (1) ◽  
pp. 63-75
Author(s):  
Rajesh Kumar Behera ◽  
Birajendu Prasad Samal ◽  
Sarat Chandra Panigrahi ◽  
Sudhansu Ranjan Das
Keyword(s):  
Design Of Experiments ◽  
Impact Velocity ◽  
Metal Matrix ◽  
Erosion Rate ◽  
Desirability Function ◽  
Impact Angle ◽  
Experimental Results ◽  
Function Approach ◽  
The Impact ◽  
Desirability Function Approach

Abstract Metal matrix composites are expanding their range every day due to their various industrial applications in manufacturing sectors, to attain high performance and favorable characteristics such as light weight, more excellent corrosion as well as wear resistance, high specific strength and high temperature-resistance than conventional materials. This study deals with analysis on erosion wear characteristic and corrosion behavior of newly-engineered aluminum metal–matrix composite (Al–0.5Si–0.5Mg–2.5Cu–5SiC) developed by powder metallurgy method. Solid particle erosion test was conducted on the newly developed AMMC product and the execution of design of experiments through Taguchi and statistical techniques demonstrates the feasibility of investigating the erosion characterization and behaviors of the composites. Sixteen set of experimental trials were performed by considering three process parameters (impact angle, stand-off distance, and impact velocity) associated with four levels each. Experimental results in accordance of Taguchi’s orthogonal array design of experiments are analyzed by employing analysis of variance (ANOVA), response surface methodology (RSM) and desirability function approach for analysis, predictive modeling and optimization of erosion rate, respectively. Thereafter, an observation on eroded surface morphology is performed under the influence of impact velocity by employing scanning electron microscope (SEM) to entrench the process. Result shows that, the impact velocity followed by impact angle have significant contribution (80.42 and 8.71%, respectively) in improvement of erosion rate. The methodology proposed in this study collects the experimental results and builds a mathematical model in the domain of interest and optimized the process model. Under the highest desirability (1), desirability-function approach of RSM presented the optimal manufacturing conditions at impact velocity of 18 m/s, stand-off distance of 26 mm and impact angle of 67° with estimated erosion rate of 65.155 mg/kg. The experimental data generated for Al–0.5Si–0.5Mg–2.5Cu–5SiC AMMC will be useful for the industry.

Sign in / Sign up

Export Citation Format

Share Document