Investigation of the reflection of perturbations from the subsonic part of a laval nozzle

1975 ◽  
Vol 8 (1) ◽  
pp. 75-83
Author(s):  
A. N. Kraiko ◽  
A. A. Osipov
Keyword(s):  

A family of exact solutions is found for the problem of steady irrotational isentropic shockfree transsonic flow of a perfect gas through a Laval nozzle in two dimensions. The hodograph method is used, whereby the position co-ordinates x , y are expressed in terms of the velocity variables; the expressions are infinite series in the subsonic part of the flow field, infinite integrals (analytic continuations of the series) in the supersonic part. An inversion is required to get the velocity as a function of position; in general, this requires detailed numerical calculations, but approximate formulae (62) are found for the neighbourhood of the sonic point on the axis.


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.


2015 ◽  
Vol 667 ◽  
pp. 449-454
Author(s):  
Yang Hong ◽  
Xiang Zhang ◽  
Dong Xiang Shao ◽  
Guang Lin Wang ◽  
Li Sun

This paper proposes a hydraulic measurement model for measuring the Laval nozzle throat diameter size. Based on measurement principle of liquid pressure – flowrate, we can get the size of Laval nozzle throat diameter by measuring the fluid flowrate through hydraulic measurement model at the fixed pressure. With good viscosity-temperature performance, low temperature performance and oxidation stability, UCBO aviation hydraulic oil is selected as the measuring medium. In the hydraulic measurement model, the diameter of the mandrel which can be regarded as gauge will directly affect the sensitivity of diameter measurement. Therefore we need to optimize the design of the mandrel of the hydraulic model.


1988 ◽  
Vol 25 (1) ◽  
pp. 88-90 ◽  
Author(s):  
Stefan Riedelbauch ◽  
Claus Weiland
Keyword(s):  

2017 ◽  
Vol 29 (6) ◽  
pp. 1035-1043 ◽  
Author(s):  
Zhao-xin Gong ◽  
Chuan-jing Lu ◽  
Jie Li ◽  
Jia-yi Cao

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.


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