Incompressible Jet Flows in a de Laval Nozzle with Smooth Detachment

2018 ◽  
Vol 232 (2) ◽  
pp. 1031-1072 ◽  
Author(s):  
Jianfeng Cheng ◽  
Lili Du ◽  
Wei Xiang
Author(s):  
Nicholas Goodman ◽  
Brian J Leege ◽  
Peter E Johnson

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.


2014 ◽  
Vol 59 (3) ◽  
pp. 879-886 ◽  
Author(s):  
M. Winnicki ◽  
T. Piwowarczyk ◽  
A. Małachowska ◽  
A. Ambroziak

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.


2004 ◽  
Vol 611 (1) ◽  
pp. 575-586 ◽  
Author(s):  
M. Opher ◽  
P. C. Liewer ◽  
M. Velli ◽  
L. Bettarini ◽  
T. I. Gombosi ◽  
...  

2016 ◽  
Vol 55 (2S) ◽  
pp. 02BC12
Author(s):  
Yusuke Teraguchi ◽  
Yuki Ishidzuka ◽  
Tomoki Nakamura ◽  
Kazumasa Takahashi ◽  
Yasuhiro Tamayama ◽  
...  

Author(s):  
V. V. Golub ◽  
S. V. Efremov ◽  
A. S. Saveliev

AIAA Journal ◽  
1999 ◽  
Vol 37 (7) ◽  
pp. 798-804 ◽  
Author(s):  
N. J. Lawson ◽  
G. J. Page ◽  
N. A. Halliwell ◽  
J. M. Coupland

A Contour shaped rocket nozzle, commonly known as Bell nozzle, is a more efficient form of a De-Laval nozzle useful for operation at different altitudes resulting in variable pressure ratio across the nozzle. Here the penetration length during the flow is calculated in a De-Laval nozzle using Computational fluid dynamics (CFD). The TOP nozzle] by G.V.R. Rao is modeled and simulated using CFD analysis by varying the divergent half angle of the bell nozzle. The geometry of different divergent angle of the bell nozzle is modeled using MATLAB code. The modeled geometry and mesh of the nozzle is simulated in ANSYS-FLUENT software. The simulation shows the variation in different flow parameter at different divergent half angles. The analysis so far for the same is done in a conical shaped rocket nozzle at the cost of varying the divergent length for changing the divergent half angle of the nozzle. This project simulates bell nozzle with constant divergent length. The simulation model is verified and validated using experimental and computational data at an NPR (Nozzle pressure ratio) of 1000. As the Rao Nozzle is used currently in rocket, missile, and satellite control systems worldwide. This research work to show how the penetration length effect the Mass-Weighted average Mach number in a particular designed bell nozzle with different divergent half angle. Based on the results obtained, the discussion is done about the parameters and the conclusion is given


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