Struktura Płaskiej Fali Uderzeniowej

This paper constitutes a summary of results of investigations of steady plane shock wave in a viscous heat conducting gas. Sec. 2 the principal part of the paper contains a discussion of the results obtained. on the basis of the equations of mechanics of continuous media. The influence of various...

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Main Author: Włodzimierz Prosnak
Format: Article
Language:English
Published: Institute of Fundamental Technological Research 1955-09-01
Series:Engineering Transactions
Online Access:https://et.ippt.pan.pl/index.php/et/article/view/3044
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author Włodzimierz Prosnak
author_facet Włodzimierz Prosnak
author_sort Włodzimierz Prosnak
collection DOAJ
description This paper constitutes a summary of results of investigations of steady plane shock wave in a viscous heat conducting gas. Sec. 2 the principal part of the paper contains a discussion of the results obtained. on the basis of the equations of mechanics of continuous media. The influence of various factors on the type of variability of hydrodynamic parameters are discussed, including the influence of viscosity and of heat conductivity. Special consideration has been given ito the phenomenon. of local decrease of entropy, [11], accompanying the overall increase of entropy. This phenomenon is not contrary to the second law of thermodynamics, because the elements of a heat conducting gas do not constitute isolated systems. This is confirmed indirectly by the fact that the shock wave in a viscous non conducting gas is characterized by a monotonic increase of entropy. Next, the results based on the principles of mechanics of continuous media are compared to those of the kinetic theory and to experimental data. It was found that the principles of mechanics of continuous media yield, for a sufficiently weak shock wave (up to Ma1~ 1,6), a qualilatively correct variability of hydrodynamic parameters, the quantitative differences being insignificant and consisting in steeper curves than those resulting from the kinetic theory. On the other hand, it appears that in the range of sufficiently strong waves qualitative differences will appear: the kinetic theory, [16], indicates here contrarily to the principles of mechanics of continuous media nonmonotonic variations of hydrodynamic parameters. The results of the kinetic theory, [16] and [18], are uncertain, however, in the range of strong waves, because in this case the state of gas can be different from that of thermal equilibrium; moreover, these results are too fragmentary to be taken as a basis for an opinion on the structure of a strong wave and to allow the results of the mechanics of continuous media to be discussed ([17] does not present any information on the structure, but only calculations of wave thickness). Measurements of shock wave thickness, [20], for Ma1 = 1,4, which constitute the unique and imperfect basis of comparison between theory and practice, confirm the results of the theory.
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spelling doaj-art-e92cb6d5928240619cc2c2d5460b36d02025-08-20T03:49:50ZengInstitute of Fundamental Technological ResearchEngineering Transactions0867-888X2450-80711955-09-0133Struktura Płaskiej Fali UderzeniowejWłodzimierz Prosnak This paper constitutes a summary of results of investigations of steady plane shock wave in a viscous heat conducting gas. Sec. 2 the principal part of the paper contains a discussion of the results obtained. on the basis of the equations of mechanics of continuous media. The influence of various factors on the type of variability of hydrodynamic parameters are discussed, including the influence of viscosity and of heat conductivity. Special consideration has been given ito the phenomenon. of local decrease of entropy, [11], accompanying the overall increase of entropy. This phenomenon is not contrary to the second law of thermodynamics, because the elements of a heat conducting gas do not constitute isolated systems. This is confirmed indirectly by the fact that the shock wave in a viscous non conducting gas is characterized by a monotonic increase of entropy. Next, the results based on the principles of mechanics of continuous media are compared to those of the kinetic theory and to experimental data. It was found that the principles of mechanics of continuous media yield, for a sufficiently weak shock wave (up to Ma1~ 1,6), a qualilatively correct variability of hydrodynamic parameters, the quantitative differences being insignificant and consisting in steeper curves than those resulting from the kinetic theory. On the other hand, it appears that in the range of sufficiently strong waves qualitative differences will appear: the kinetic theory, [16], indicates here contrarily to the principles of mechanics of continuous media nonmonotonic variations of hydrodynamic parameters. The results of the kinetic theory, [16] and [18], are uncertain, however, in the range of strong waves, because in this case the state of gas can be different from that of thermal equilibrium; moreover, these results are too fragmentary to be taken as a basis for an opinion on the structure of a strong wave and to allow the results of the mechanics of continuous media to be discussed ([17] does not present any information on the structure, but only calculations of wave thickness). Measurements of shock wave thickness, [20], for Ma1 = 1,4, which constitute the unique and imperfect basis of comparison between theory and practice, confirm the results of the theory. https://et.ippt.pan.pl/index.php/et/article/view/3044
spellingShingle Włodzimierz Prosnak
Struktura Płaskiej Fali Uderzeniowej
Engineering Transactions
title Struktura Płaskiej Fali Uderzeniowej
title_full Struktura Płaskiej Fali Uderzeniowej
title_fullStr Struktura Płaskiej Fali Uderzeniowej
title_full_unstemmed Struktura Płaskiej Fali Uderzeniowej
title_short Struktura Płaskiej Fali Uderzeniowej
title_sort struktura plaskiej fali uderzeniowej
url https://et.ippt.pan.pl/index.php/et/article/view/3044
work_keys_str_mv AT włodzimierzprosnak strukturapłaskiejfaliuderzeniowej