Statistical and numerical study of the relationship between turbulence and sonic boom characteristics

1994 ◽  
Vol 96 (6) ◽  
pp. 3621-3626 ◽  
Author(s):  
Richard Raspet ◽  
Henry E. Bass ◽  
Lixin Yao ◽  
Patrice Boulanger ◽  
Walton E. McBride
Keyword(s):  
Numerical Study ◽  
Sonic Boom ◽  
The Relationship

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

Failure behavior analysis of steel strip–reinforced flexible pipe under combined tension and internal pressure

2018 ◽  
Vol 33 (6) ◽  
pp. 727-753
Author(s):  
Wei Chen ◽  
Haichao Xiong ◽  
Yong Bai
Keyword(s):  
Internal Pressure ◽  
Numerical Study ◽  
Steel Strip ◽  
Sensitivity Study ◽  
Failure Behavior ◽  
Load Path ◽  
Flexible Pipe ◽  
Fe Method ◽  
Axial Extension ◽  
The Relationship

The mechanical behaviors of steel strip–reinforced flexible pipe (steel strip PSP) under combined axial extension → internal pressure ( T→ P) load path were investigated. Typical failure characteristics of pipe samples under pure internal pressure and T→ P load path were identified in the full-scale experiments. A theoretical model for pipe under tension load was proposed to capture the relationship between axial extension of the pipe body and stress state of the steel strip. Numerical study based on finite element (FE) method was conducted to simulate the experiment process, and good agreement between FE data and experiment results were observed. Sensitivity study was conducted to study the effect of some key parameters on the pipe antiburst capacities in T→P load path; the effect of preloaded internal pressure on the pipe tensile capacity in P→T load path was also studied. Useful conclusions were drawn for the design and application of the steel strip PSP.

scholarly journals Numerical Study of Hydrodynamic Impact on Bubbly Water

2015 ◽  
Author(s):  
Mehdi Elhimer ◽  
Aboulghit El Malki Alaoui ◽  
Kilian Croci ◽  
Céline Gabillet ◽  
Nicolas Jacques
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Numerical Data ◽  
Void Volume Fraction ◽  
Bubbly Liquid ◽  
Impact Loads ◽  
Hydrodynamic Impact ◽  
Physical Mechanisms ◽  
The Impact ◽  
The Relationship

The phenomenon of slamming on a bubbly liquid has many occurrences in marine and costal engineering. However, experimental or numerical data on the effect of the presence of gas bubbles within the liquid on the impact loads are scarce and the related physical mechanisms are poorly understood. The aim of the present paper is to study numerically the relationship between the void volume fraction and the impact loads. For that purpose, numerical simulations of the impact of a cone on bubbly water have been performed using the finite element code ABAQUS/Explicit. The present results show the diminution of the impact loads with the increase of the void fraction. This effect appears to be related to the high compressibility of the liquid-gas mixture.

A Numerical Study for the Relationship between Natural Manganese Dendrites and DLA Patterns

2016 ◽  
Vol 71 (3) ◽  
pp. 225-234
Author(s):  
Tugba Ozbey ◽  
Mehmet Bayirli
Keyword(s):  
Critical Exponent ◽  
Numerical Study ◽  
Formation Mechanisms ◽  
Diffusion Limited Aggregation ◽  
Density Correlation ◽  
Diffusion Limited ◽  
Crystalline Anisotropy ◽  
The Relationship ◽  
Good Agreement ◽  
Dla Model

AbstractThe formation mechanisms and the origin of manganese dendrites on the magnesite ore have been under discussion. The growth process of the manganese dendrites is statistically studied by comparing them to aggregations obtained according to the diffusion limited aggregation (DLA) model via Monte Carlo simulations. In this case, ten manganese dendrite patterns changing from the least dense to the densest aggregations on the surface are separately selected to determine the relationship between real and simulated patterns. The sticking parameter is ranged from 0.05≤t≤1. The density–density correlation functions C(r) (their critical exponent A), fractal dimension Df, critical exponent α, and critical exponent β pertaining to the root mean square (rms) thickness have been computed for both the ten manganese dendrites and the simulated aggregations representing them. The results indicate that manganese dendrites may be determined with the general DLA model. Analyses of manganese dendrites, both scaling and simulations, suggest the growth mechanism for the macroscopic expression of crystalline anisotropy for the dendritic patterns. These results are in good agreement with the values in other literature and can be helpful in comparing natural and simulated aggregations (both dendritic and compact deposits).

Numerical Study on Explosion Cutting Process of PMMA Plate and Key Factors Influence on Cutting Performance

2018 ◽  
Author(s):  
Lei Ge ◽  
Yantao Wang ◽  
Huipeng Hu ◽  
Lijun Li ◽  
Yiben Zhang
Keyword(s):  
Numerical Study ◽  
Engineering Application ◽  
Material Model ◽  
Cutting Performance ◽  
Cutting Process ◽  
Transient Pressure ◽  
Key Factors ◽  
Explicit Solver ◽  
The Relationship ◽  
Selection Of

Polymethylmethacrylate (PMMA) has been widely utilized to manufacture the covers of aircraft cockpits, naval vessels, car windows and so on, due to their high transmittance, low density, easy processing formability, high corrosion resistance and excellent mechanical properties. Under special conditions such as ejection lifesaving, the PMMA plate needs to be split precisely by explosion cutting technology. Hence, an accurate numerical simulation of PMMA structures is significantly important in engineering application. This paper aims to study the cutting behavior of PMMA plate numerically and investigate the influencing factors on cutting performance of PMMA plates. First of all, the simulation of explosion cutting process of PMMA plate is carried out by a non-linear explicit solver in LS-DYNA software using the fluid-solid coupling method. Jones-Wilkins-Lee (JWL) equation of state is used to simulate the relationship between the transient pressure and specific volume of explosives during explosion. The material model considering failure behaviors is used in the simulation. Additionally, the influence of explosive dosage as well as explosive type on the cutting performance of PMMA plate is investigated. Furthermore, the effect of PMMA geometry size on cutting performance is discussed. This study contributes to the knowledge for the design of PMMA structures which needs explosion cutting and the selection of explosive dosage and explosive type.

scholarly journals Influence of the lateral source/building separation on vapour intrusion: A numerical study

2020 ◽  
Vol 172 ◽  
pp. 07006
Author(s):  
Juan Sebastian Rios Mora ◽  
Bernard Collignan ◽  
Thierno Diallo ◽  
Marc Abadie ◽  
Karim Limam
Keyword(s):  
Vadose Zone ◽  
Numerical Study ◽  
Pollution Source ◽  
Source Position ◽  
Air Concentration ◽  
Indoor Concentration ◽  
Volatile Organic ◽  
Vapour Flux ◽  
The Relationship

Various vapour intrusion (VI) models have been proposed in order to predict indoor concentration of Volatile Organic Compounds (VOCs) in buildings. However, these models tend to be conservative, and overestimate or underestimate vapour flux emissions due to several assumptions. Particularly, most of these VI models only consider an infinite uniform contaminated groundwater as the principal source of VOCs in the soil, and lateral pollution source in the vadose zone are disregarded. It has been shown that ignoring the lateral source position may lead to uncertainties on the estimations. In this paper, a numerical model is developed in order to better understand the relationship between the lateral source position in the soil, including both a source in the vadose zone and a source located at the groundwater level, and the resulting indoor air concentration. Results show that source position plays a significant role on vapour intrusion attenuation. In fact, indoor concentration of VOCs decreases with increasing lateral separation. Finally, it is shown that considering the source position can significantly improve the quality of VI predictions.

Numerical study of the of sonic boom near-field

2019 ◽  
Author(s):  
P. A. Mishchenko ◽  
T. A. Kiseleva
Keyword(s):  
Numerical Study ◽  
Near Field ◽  
Sonic Boom
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