Numerical Solution of Internal Flow through a de Laval Nozzle Based on the Euler Model with the SU2 Code: Verification and Validation

2020 ◽  
Author(s):  
Giovanne Deni Iorio ◽  
Guilherme Bertoldo ◽  
Carlos Henrique Marchi
Keyword(s):  
Numerical Solution ◽  
Laval Nozzle ◽  
Internal Flow ◽  
Verification And Validation ◽  
Code Verification ◽  
De Laval Nozzle ◽  
Euler Model ◽  
Flow Through

ACCRETION ONTO COMPACT OBJECTS VIEWED AS A FLOW IN CONVERGING-DIVERGING DUCTS

2008 ◽  
Vol 17 (05) ◽  
pp. 799-814 ◽  
Author(s):  
K. CHAKRABARTI ◽  
M. M. MAJUMDAR ◽  
SANDIP K. CHAKRABARTI
Keyword(s):  
Laval Nozzle ◽  
Engineering Problem ◽  
Compact Objects ◽  
Shock Formation ◽  
Accretion Flow ◽  
Black Hole Accretion ◽  
De Laval Nozzle ◽  
Flow Through ◽  
Saddle Type ◽  
Hole Accretion

Black hole accretion is necessarily transonic and the number of physical sonic points depends on the angular momentum of the flow. We study the properties of such a flow by recasting this idea into an engineering problem in which a flow has a subsonic to supersonic transition when it passes through a de Laval nozzle, i.e. a converging and diverging duct in a flat geometry in the presence of sufficient end pressure difference. Particularly interesting is the case of the centrifugal pressure supported standing shock formation inside an accretion flow, because the flow passes through at least two saddle type sonic points, one before and one after the shock. In this case, the duct itself has two minima and a maximum. We study the properties of such a duct as a function of the inflow parameters and classify all possible types of the flow through this composite nozzle.

An Example of Code Verification in the Simulation of Wave Propagation

2011 ◽  
Author(s):  
Fahd Fathi ◽  
Lui´s Ec¸a ◽  
Mart Borsboom
Keyword(s):  
Wave Propagation ◽  
Numerical Solution ◽  
Physical Reality ◽  
Verification And Validation ◽  
Cfd Modeling ◽  
Code Verification ◽  
Complex Flows ◽  
Solution Verification ◽  
The Mathematical Model

Thanks to advances in modeling and hardware the range of applications available to CFD modeling is continuously increasing. As CFD has moved from demonstration of capability to production of engineering results of practical value, there is an increased awareness in the field that Verification and Validation are systematically required. Verification deals with the numerical accuracy of a given set of results. Its object is the assessment of the numerical uncertainty due to discretization and iterative errors of a numerical solution (Solution Verification) performed with a Code that has been previously checked to be free of errors (Code Verification). Both activities are required to ensure that errors are controlled and that quality of the results is maintained. Complementarily, Validation addresses the modeling error, i.e. the comparison of the mathematical model with the (physical) reality. Therefore, it requires comparison with experimental data. Validating CFD results is only meaningful when preceded by carefully verified calculations (Solution Verification) with verified codes (Code Verification). The topic of Verification and Validation is developing and standardized procedures are still under discussion. Nevertheless, there are techniques available to perform careful Code and Solution Verification for flows with engineering relevance. This paper presents a Code Verification exercise for the simulation of wave propagation with a VOF code. Systematically refined grids and time steps are applied in the calculation of waves with a known analytical solution to assess the convergence properties of the numerical solution. The aim of the exercise is to demonstrate the advantages of such exercises for the knowledge of the numerical properties of a code that is applied in complex flows. The study is not a pure Code Verification exercise. Modeling errors introduced by approximate outlet boundary conditions (allowing wave reflections) are also quantified for a linear and a high-order wave. However, these are still based on (numerical) error evaluations for known analytical solutions and so they can still be classified as Code Verification.

Computational Studies on Flow Through De Laval Nozzle

2006 ◽  
Vol 23 (4) ◽  
Author(s):  
C. Manisankar ◽  
S. Gnanasekar ◽  
C.Senthil Kumar ◽  
S. Elangovan ◽  
E. Rathakrishnan
Keyword(s):  
Laval Nozzle ◽  
Computational Studies ◽  
De Laval Nozzle ◽  
Flow Through

An improved de Laval nozzle experiment

2021 ◽  
pp. 030641902110341
Author(s):  
Nicholas Goodman ◽  
Brian J Leege ◽  
Peter E Johnson
Keyword(s):  
Data Acquisition ◽  
Laval Nozzle ◽  
Flow Characteristics ◽  
Data Acquisition System ◽  
Isentropic Flow ◽  
Hands On ◽  
De Laval Nozzle ◽  
Physical Phenomena ◽  
The Impact ◽  
The Relationship

Exposing students to hands-on experiments has been a common approach to illustrating complex physical phenomena that have been otherwise modelled solely mathematically. Compressible, isentropic flow in a duct is an example of such a phenomenon, and it is often demonstrated via a de Laval nozzle experiment. We have improved an existing converging/diverging nozzle experiment so that students can modify the location of the normal shock that develops in the diverging portion to better understand the relationship between the shock and the pressure. We have also improved the data acquisition system for this experiment and explained how visualisation of the standing shock is now possible. The results of the updated system demonstrate that the accuracy of the isentropic flow characteristics has not been lost. Through pre- and post-laboratory quizzes, we show the impact on student learning as well.

scholarly journals Effect of Gas Pressure and Temperature on Stereometric Properties of Al+Al2O3 Composite Coatings Deposited by LPCS Method

2014 ◽  
Vol 59 (3) ◽  
pp. 879-886 ◽  
Author(s):  
M. Winnicki ◽  
T. Piwowarczyk ◽  
A. Małachowska ◽  
A. Ambroziak
Keyword(s):  
Laval Nozzle ◽  
Composite Coatings ◽  
Gas Pressure ◽  
Feedstock Powder ◽  
Substrate Distance ◽  
Al2o3 Composite ◽  
Spray Method ◽  
Powder Mass ◽  
De Laval Nozzle ◽  
Temperature And Pressure

Abstract The paper deals with effect of working gas pressure and temperature on surface stereometry of coatings deposited by low-pressure cold spray method. Examinations were focused on aluminium coatings which are commonly used to protect substrate against corrosion. A commercial Al spherical feedstock powder with admixture of Al2O3 (Al + 60vol.-% Al2O3), granulation -50+10 µm, was used to coat steel, grade S235JR. Thedeposited coatings were studied to determine their stereometry, i.e. roughness, transverse and longitudinal waviness, topography of surface and thickness as the functions of gas pressure and temperature. A profilometer and focal microscope were used to evaluate the stereometric properties. In order to reduce the number of variables, the remaining process parameters, i.e. shape and size of de Laval nozzle, nozzle-to-substrate distance, powder mass flow rate, linear velocity of spraying gun, were kept unchanged. The investigation confirmed influence of temperature and pressure on coating thickness as well as on the surface seterometry.

Numerical solutions to wave interaction with rubblemound breakwaters

1990 ◽  
Vol 17 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Kevin R. Hall
Keyword(s):  
Numerical Modelling ◽  
Numerical Solution ◽  
Numerical Solutions ◽  
Scale Effects ◽  
Numerical Models ◽  
Internal Flow ◽  
Wave Interaction ◽  
Theoretical Development ◽  
Porous Media Flow ◽  
Complex Flow

The interaction of a wave with a rubblemound breakwater results in a complex flow field which is both nonlinear and turbulent, particularly within a region close to the surface of the structure. Numerical models describing internal flow in a rubblemound breakwater are becoming increasingly important, particularly as the influence of scale effects on internal flow in physical hydraulic models are becoming understood as important. A number of numerical models to predict the internal breakwater flow kinematics have been produced in the past two decades. This paper provides a review of the state-of-the-art of numerical modelling of wave interaction with rubblemound breakwaters. Details of the theoretical development and the resulting numerical solution techniques are presented. Methods for incorporating secondary effects such as two-phase (air–water) flow, inertia, and unbalanced boundary conditions are discussed. Limitations of the models resulting from the validity of the assumptions made in order to effect a numerical solution are discussed. Key words: breakwaters, internal flow, porous media flow, numerical modelling, rubblemound breakwaters.

Sign in / Sign up

Export Citation Format

Share Document