Boiling during high-velocity impact of water droplets on a hot stainless steel surface

2006 ◽  
Vol 462 (2074) ◽  
pp. 3115-3131 ◽  
Author(s):  
Navid Z Mehdizadeh ◽  
Sanjeev Chandra
Keyword(s):  
Stainless Steel ◽  
Substrate Temperature ◽  
Impact Velocity ◽  
High Velocity ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
High Velocity Impact ◽  
Water Droplets ◽  
Velocity Impact ◽  
The Impact

High-velocity impact of water droplets (0.55 mm diameter) on a heated stainless steel surface was photographed. To achieve high impact velocities, the test surface was mounted on the rim of a rotating flywheel, giving linear velocities of up to 50 m s −1 . Two cartridge heaters were inserted in the substrate and used to vary substrate temperature. A charge coupled device (CCD) video camera was used to photograph droplets impinging on the substrate. To photograph different stages of droplet impact, the ejection of a single droplet was synchronized with the position of the rotating flywheel and triggering of the camera. Substrate temperature was varied from 100 to 240 °C and the impact velocity from 10 to 30 m s −1 . High-resolution photographs were taken of vapour bubbles nucleating sites inside the thin liquid films produced by spreading droplets. An analytical expression was derived for the amount of superheat required for vapour bubble nucleation as a function of the impact velocity. For a given surface roughness, the amount of superheat needed decreased with impact velocity, which agreed with experimental results. For a fixed impact velocity, the maximum extent of droplet spread increased with substrate temperature.

Effect of Impact Velocity and Substrate Temperature on Boiling of Water Droplets Impinging on a Hot Stainless Steel Surface

Volume 3 ◽  
2004 ◽  
Author(s):  
N. Z. Mehdizadeh ◽  
S. Chandra
Keyword(s):  
Stainless Steel ◽  
Substrate Temperature ◽  
Impact Velocity ◽  
Steel Surface ◽  
Bubble Nucleation ◽  
Test Surface ◽  
Stainless Steel Surface ◽  
Water Droplets ◽  
Droplet Spreading ◽  
The Impact

We photographed high velocity impact of small water droplets (0.55 mm) on a heated stainless steel surface. To achieve high impact velocities the test surface was mounted on the rim of a rotating flywheel, giving linear velocities of up to 50 m/s. Two cartridge heaters were inserted in the substrate and used to vary substrate temperature. A CCD video camera was used to photograph droplets impinging on the substrate. By synchronizing the ejection of a single droplet with the position of the rotating flywheel and triggering of the camera, different stages of droplet impact were photographed. Substrate temperature was varied from 100–240°C and the impact velocity from 10–30 m/s. High-resolution photographs were taken of vapor bubbles nucleating sites inside the thin films produced by spreading droplets. For a given impact velocity, the extent of droplet spreading increased with substrate temperature. The superheat needed to initiate bubble nucleation decreased with impact velocity. We derived an analytical expression for the amount of superheat required for vapor bubble nucleation as a function of impact velocity.

Splashing of a Small Droplet Impinging on a Solid Surface at High Velocity

2000 ◽  
Author(s):  
N. Z. Mehdizadeh ◽  
S. Chandra ◽  
J. Mostaghimi
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Impact Velocity ◽  
Steel Substrate ◽  
Video Camera ◽  
Droplet Impact ◽  
Stainless Steel Surface ◽  
Water Droplets ◽  
Produce Water ◽  
The Impact

Abstract We photographed water droplets (550 μm diameter) as they impacted on a stainless steel surface. We varied droplet impact velocity (10–40 m/s) and the average surface roughness (0.03–0.23 μm) of the steel plates used as test surfaces in our experiments. A piezoelectric droplet generator was used to produce water droplets. The stainless steel substrate was mounted on the end of a rotating arm, giving linear velocities of up to 40 m/s. A CCD video camera was used to photograph droplets impinging on the substrate. By synchronizing the ejection of a single droplet with the position of the rotating arm and triggering of the camera, different stages of droplet impact were photographed. From these photographs we measured the size of droplets as they spread. It was observed that as the impact velocity increased, finger-shape perturbations around the spreading droplet became longer and narrower. At sufficiently high velocities the tips of these fingers detached, producing satellite droplets. Increasing surface roughness was found to promote splashing and reduce the velocity at which splashing was first observed. By increasing surface roughness, both the number of fingers and the maximum extent of spreading were decreased. At high impact velocities the spreading liquid film became so thin that it ruptured in several places.

The High Velocity Impact Response of Novel Fiber Metal Laminates

2001 ◽  
Author(s):  
Wesley J. Cantwell ◽  
Graham Wade ◽  
J. Fernando Guillen ◽  
German Reyes-Villanueva ◽  
Norman Jones ◽  
...  
Keyword(s):  
High Velocity ◽  
Impact Resistance ◽  
High Velocity Impact ◽  
Fiber Metal Laminates ◽  
Velocity Impact ◽  
Glass Fiber Reinforced ◽  
Fiber Metal ◽  
Energy Absorbing ◽  
Dynamic Loading Conditions ◽  
The Impact

Abstract The impact resistance of a range of novel fiber metal laminates based on polypropylene, polyamide and polyetherimide matrices has been investigated. Initial attention focused on optimizing the interface between the composite and aluminum alloy constituents. Here, it was shown that composite-metal adhesion was excellent in all systems examined. In addition, tests at crosshead displacement rates up to 3 m/s indicated that the interfacial fracture energies remained high under dynamic loading conditions. High velocity impact tests on a series of 3/2 laminates (3 layers of aluminum/2 layers of composite) highlighted the outstanding impact resistance of a number of these systems. The glass fiber reinforced polypropylene system offered a particularly high impact resistance exhibiting a perforation energy of approximately 160 Joules. Here, failure mechanisms such as extensive plastic drawing in the aluminum layers and fiber fracture in the composite plies were found to contribute to the excellent energy-absorbing characteristics of these systems.

The fracture properties of fiber metal laminates based on a 3D printed glass fiber composite

2020 ◽  
pp. 089270572097617
Author(s):  
B Yelamanchi ◽  
E MacDonald ◽  
NG Gonzalez-Canche ◽  
JG Carrillo ◽  
P Cortes
Keyword(s):  
3D Printing ◽  
Glass Fiber ◽  
High Velocity ◽  
Metal Composite ◽  
High Velocity Impact ◽  
Fiber Metal Laminates ◽  
Velocity Impact ◽  
Impact Performance ◽  
Fiber Metal ◽  
The Impact

Fiber Metal Laminates (FML) are structures that contain a sequential arrangement of metal and composite materials, which are of great interest to the aerospace sector due to the superior mechanical performance. The traditional manufacturing process for FML involves considerable investment in manufacturing resources depending on the design complexity of the desired components. To mitigate such limitations, 3D printing enables direct digital manufacturing to create FML with customized configurations. In this work, a preliminary mechanical characterization of additively-manufacturing-enabled FML has been investigated. A series of continuous glass fiber-reinforced composites were printed with a Markforged system and placed between layers of aluminum alloy to manufacture hybrid laminate structures. The laminates were subjected to tensile, interfacial fracture toughness, and both low-velocity and high-velocity impact tests. The results showed that the FMLs appear to have a good degree of adhesion at the metal-composite interface, although a limited intralaminar performance was recorded. It was also observed that the low and high-velocity impact performance of the FMLs was improved by 9–13% relative to that of the constituent elements. The impact performance of the FML appeared to be related to the fiber fracture, out of plane perforation and interfacial delamination within the laminates. The present study can provide an initial research foundation for considering 3D printing in the production of hybrid laminates for static and dynamic applications.

Study of the Impact Performance of Solder Joints by High-Velocity Impact Tests

2010 ◽  
Vol 39 (12) ◽  
pp. 2536-2543 ◽  
Author(s):  
Ning Zhang ◽  
Yaowu Shi ◽  
Fu Guo ◽  
Fuqian Yang
Keyword(s):  
High Velocity ◽  
Solder Joints ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Impact Performance ◽  
Impact Tests ◽  
The Impact

THE MECHANISM OF SHOCK COMMINUTION OF 3D C/SIC COMPOSITE SUBJECTED TO HIGH VELOCITY IMPACT

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1510-1517
Author(s):  
QINGMING ZHANG ◽  
FENGLEI HUANG ◽  
LI CHEN ◽  
LIMING HAN ◽  
JINZHU LI
Keyword(s):  
Experimental Investigation ◽  
High Velocity ◽  
Ceramic Matrix Composite ◽  
Three Dimensional ◽  
Ceramic Matrix ◽  
Impact Point ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Sic Ceramic ◽  
The Impact

In this paper, experimental investigation and theoretical analysis are carried out in an attempt to study the response of SiC ceramic matrix composite reinforced with three dimensional braided fabric(3 D C/SiC ) under high velocity impact. The results show that 3 D C/SiC composite will be turned into comminution if the pressure of the impact point resulted from the projectile impacting 3 D C/SiC composite sample is larger than 780Mpa. Based on the analysis of the mechanism of composite comminution, a theoretical model has been developed.

Splat Solidification of Tin Droplets

1996 ◽  
Author(s):  
R. Bhola ◽  
S. Chandra
Keyword(s):  
Experimental Study ◽  
Stainless Steel ◽  
Simple Model ◽  
Surface Temperature ◽  
Steel Surface ◽  
Liquid Droplet ◽  
Contact Angles ◽  
Stainless Steel Surface ◽  
Splat Solidification ◽  
The Impact

Abstract An experimental study was done of the impact and solidification of tin droplets falling on a stainless steel surface. The surface temperature was varied from 25°C to 240°C. Measurements were made of droplet diameters and contact angles during droplet spread. At a surface temperature of 240°C there was no solidification, and a simple model of liquid droplet impact successfully predicted the extent of droplet spread. Droplets impacting on surfaces at 25°C and 150°C solidified before spreading was complete.

Numerical Modeling of Energy Absorption Behaviour of Aluminium Foam Cored Sandwich Panels with Different Fibre Reinforced Polymer (FRP) Composite Facesheet Skins

2016 ◽  
Vol 852 ◽  
pp. 66-71 ◽  
Author(s):  
M. Nalla Mohamed ◽  
D. Ananthapadmanaban ◽  
M. Selvaraj
Keyword(s):  
Energy Absorption ◽  
High Velocity ◽  
Sandwich Panels ◽  
Aluminium Foam ◽  
Foam Core ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
The Impact

Sandwich structures based on Fibre Reinforced Polymer (FRP) facesheet skins bonded with low density aluminium foam core are increasing in use in aerospace and marine industries. These structures are very sensitive to high velocity impact during the service. Therefore, it is necessary to study the energy absorption of the structures to ensure the reliability and safety in use. Experimental investigation of these transient events is expensive and time-consuming, and nowadays the use of numerical approaches is on the increase. Hence, the purpose of this paper is to develop a numerical model of sandwich panels with aluminium foam as a core and Glass, Carbon and Kevlar Fibre Reinforced polymer composite as faceplate, subjected to high velocity impact using ABAQUS/Explicit. The influence of individual elements of the sandwich panel on the energy absorption of the structures subjected to high velocity impact loading was analysed. Selection of suitable constitutive models and erosion criterion for the damage were discussed. The numerical models were validated with experimental data obtained from the scientific literature. Good agreement was obtained between the simulations and the experimental results. The contribution of the face sheet, foam core on the impact behaviour was evaluated by the analysis of the residual velocity, ballistic limit, and damaged area.

scholarly journals The Impact Performance of Woven-Fabric Thermoplastic and Thermoset Composites Subjected to High-Velocity Soft- and Hard-Impact Loading

2019 ◽  
Vol 26 (5-6) ◽  
pp. 1389-1410 ◽  
Author(s):  
Jun Liu ◽  
Haibao Liu ◽  
Cihan Kaboglu ◽  
Xiangshao Kong ◽  
Yuzhe Ding ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Impact Loading ◽  
High Velocity ◽  
Image Correlation ◽  
Woven Fabric ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Impact Performance ◽  
The Impact ◽  
Carbon Fibre Composites

Abstract The present paper investigates the impact performance of woven-fabric carbon-fibre composites based upon both thermoplastic- and thermoset-matrix polymers under high-velocity impact loading by conducting gas-gun experiments at impact velocities of up to 100 m.s−1. The carbon-fibre reinforced-polymers (CFRPs) are impacted using soft- (i.e. gelatine) and hard- (i.e. aluminium-alloy) projectiles to simulate either a soft bird-strike or a hard foreign-body impact (e.g. runway debris), respectively, on typical composites employed in civil aircraft. The out-of-plane displacements of the impacted composite specimen are obtained by means of a three-dimensional Digital Image Correlation (DIC) system for the soft-projectile impact on the composites and the extent of damage is assessed both visually and by using portable C-scan equipment. The perforation resistance and energy absorbing capability of the composites are also studied by performing high-velocity impact experiments using the hard-projectile and the resulting extent and type of damage are identified. In addition, a Finite Element (FE) model is also developed to investigate the interaction between the projectile and the composite target.

scholarly journals High-Velocity Impact Behaviour of Prestressed Composite Plates under Bird Strike Loading

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Sebastian Heimbs ◽  
Tim Bergmann
Keyword(s):  
High Velocity ◽  
Laminated Composite ◽  
Composite Plates ◽  
Bird Strike ◽  
High Velocity Impact ◽  
General Behaviour ◽  
Simulation Accuracy ◽  
Velocity Impact ◽  
Modelling Methodology ◽  
The Impact

An experimental and numerical analysis of the response of laminated composite plates under high-velocity impact loads of soft body gelatine projectiles (artificial birds) is presented. The plates are exposed to tensile and compressive preloads before impact in order to cover realistic loading conditions of representative aeronautic structures under foreign object impact. The modelling methodology for the composite material, delamination interfaces, impact projectile, and preload using the commercial finite element code Abaqus are presented in detail. Finally, the influence of prestress and of different delamination modelling approaches on the impact response is discussed and a comparison to experimental test data is given. Tensile and compressive preloading was found to have an influence on the damage pattern. Although this general behaviour could be predicted well by the simulations, further numerical challenges for improved bird strike simulation accuracy are highlighted.

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