Behavior of waveguide modes in a neighborhood of the critical cross section

1978 ◽  
Vol 9 (4) ◽  
pp. 570-576 ◽  
Author(s):  
I. A. Molotkov
Keyword(s):  
Cross Section ◽  
Critical Cross Section ◽  
Waveguide Modes

Computation of waveguide modes for waveguides of arbitrary cross-section

1990 ◽  
Vol 137 (2) ◽  
pp. 145 ◽  
Author(s):  
C.Y. Kim ◽  
S.D. Yu ◽  
R.F. Harrington ◽  
J.W. Ra ◽  
S.Y. Lee
Keyword(s):  
Cross Section ◽  
Arbitrary Cross Section ◽  
Waveguide Modes

Numerical simulations of temperature fields in the uncooled nozzle of a short-range anti-aircraft rocket engine with an insert in the critical section made of various materials

2021 ◽  
Vol 70 (1) ◽  
pp. 15-30
Author(s):  
Mateusz Zieliński ◽  
Piotr Koniorczyk ◽  
Janusz Zmywaczyk ◽  
Marek Preiskorn
Keyword(s):  
Numerical Simulations ◽  
Cross Section ◽  
Heat Flux Density ◽  
Short Range ◽  
Rocket Engine ◽  
Transient Heat Conduction ◽  
Critical Section ◽  
Temperature Fields ◽  
Critical Cross Section ◽  
Calculation Results

Abstract. The paper presents numerical simulations of transient heat conduction in the uncooled nozzle of a short-range anti-aircraft rocket engine. The calculations were made for the configuration of the nozzle with an insert in the critical section made of various materials. The inserts used were: POCO graphite, Al2O3 ceramics, ZrO2-3Y2O3 ceramics. For comparison, numerical simulations of the heat transfer in a nozzle made entirely of St 45 steel, the melting point of which is 1700K, were also carried out. The engine's working time was in the order of 3 s. Numerical simulations were performed using the COMSOL program. The calculation results are given in the form of temperature dependence and heat flux density as a function of time in the critical cross-section. Keywords: non-cooled nozzle, rocket engine, temperature field

Electromagnetic wave propagation in a chiroplasma-filled waveguide

1999 ◽  
Vol 62 (1) ◽  
pp. 87-94 ◽  
Author(s):  
J. GONG
Keyword(s):  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Cross Section ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Propagation Constant ◽  
Circular Cross Section ◽  
Propagation Characteristics ◽  
Waveguide Modes ◽  
The Family

A dispersion equation is derived for a cylindrical waveguide of circular cross-section partially filled with chiroplasma. The propagation characteristics of electromagnetic waves in the family of waveguide modes are studied. The dispersion curves are given. It is found that the propagation constant changes almost linearly with the chirality admittance for the parameters that we choose, and increases with increasing filled area.

scholarly journals The passage of a perfect fluid through a critical cross-section or ‘throat’

1949 ◽  
Vol 197 (1051) ◽  
pp. 545-555 ◽  
Keyword(s):  
Cross Section ◽  
Liquid Flow ◽  
Axial Direction ◽  
Critical Cross Section ◽  
Local Velocity ◽  
Velocity Of Sound ◽  
Long Wave ◽  
Venturi Flume ◽  
External Forces ◽  
Horizontal Bottom

A review is given of the methods previously adopted of calculating the discharge of a gas through a convergent-divergent nozzle and of a liquid over a broad-crested weir, through a Venturi flume with a horizontal bottom, and in a swirling state through a vertical nozzle. The assumption is made throughout that conditions are uniform over each cross-section of the constriction. Hugoniot’s method is shown to be preferable, and it is used to examine the discharge of a liquid through a Venturi flume of any shape and of a swirling gas through a nozzle. It is pointed out that, if an external force is operating in the axial direction, the local velocity of sound or of a long wave, as the case may be, is not attained by the fluid at the exact geometrical throat of the constriction. For the general case of liquid flow, whether swirling or not, the axial velocity of streaming in the absence of external forces is shown to be equal at the throat to the velocity of a long wave.

Follow for Now, Volume 2: More Interviews with Friends and Heroes

2021 ◽  
Keyword(s):  
Social Media ◽  
Cross Section ◽  
Critical Cross Section ◽  
William Gibson

Follow for Now, Vol. 2 picks up and pushes beyond the first volume with a more diverse set of interviewees and interviews. The intent of the first collection was to bring together voices from across disciplines, to cross-pollinate ideas. At the time, social media wasn’t crisscrossing all of the lines and categories held a bit more sway. Volume 2 aims not only to pick up where Follow for Now left off but also to tighten its approach with deeper subjects and more timely interviews. Featuring conversations with thinkers like Carla Nappi, Rita Raley, Dominic Pettman, Ian Bogost, Mark Dery, Douglas Rushkoff, and Dave Allen, and musicians like Tyler, The Creator, Matthew Shipp, Sean Price, Rammellzee, and Sadat X, as well as writers like Ytasha L. Womack, Chris Kraus, Pat Cadigan, Bob Stephenson, Simon Critchley, Simon Reynolds, Malcolm Gladwell, and William Gibson, Follow for Now, Vol. 2 is another critical cross-section of the now.

Development of Tools for Thermodynamic Calculation of Rocket Engine Characteristics using the Julia Programming Language

2021 ◽  
pp. 80-93
Author(s):  
G.V. Belov
Keyword(s):  
Thermodynamic Properties ◽  
Cross Section ◽  
Process Model ◽  
Gas Flow ◽  
Rocket Engine ◽  
Combustion Products ◽  
Flow Speed ◽  
Critical Cross Section ◽  
Chemical Calculation ◽  
Product Flow

The experience in developing an algorithm and a program for the thermal-chemical calculation of the characteristics of a rocket engine is presented. The program is written in Julia. To calculate the equilibrium composition of combustion products the freely distributed library Ipopt is used. The program is interfaced to the database on thermodynamic properties of individual substances IVTANTERMO. For the convenience of processing, the information on thermodynamic properties is stored in two text files of a special form. The program has been developed using the simplest working process model according to which the flow is one-dimensional, the product flow is adiabatic, there are no friction losses, the product flow is equilibrium, and the speed of condensed particles is equal to the gas flow speed. Ratios for calculating the derivatives of composition, as well as equilibrium values of heat capacity and sound velocity are given. The text of the program can be used in the study process and can easily be adapted to more complex models of the rocket engine workflow. The calculation results obtained using the developed program are in good agreement with the results of TERRA calculations. The execution time of one calculation for a four-element fuel, which includes the determination of the combustion products characteristics in the chamber, the critical cross section and at the nozzle cross section, varies in the range of 3--5 s

Overall Reliability of the Concrete Columns in Case of Stability Loss

2015 ◽  
Vol 1106 ◽  
pp. 229-232 ◽  
Author(s):  
Vladimír Benko ◽  
Peter Kendický ◽  
Martin Krizma ◽  
Marian Kišac ◽  
Ivan Beleš
Keyword(s):  
Cross Section ◽  
Axial Force ◽  
Civil Engineering ◽  
Bending Moment ◽  
Concrete Columns ◽  
Stability Loss ◽  
Critical Cross Section ◽  
Loss Of Stability ◽  
European Standard ◽  
Overall Reliability

The European standard EN1992-1-1 shows a significant lack of an overall reliability in cases when loss of stability of concrete columns precedes reaching of resistance in a critical cross-section. The columns, subjected to axial force and bending moment, experimentally tested in the laboratory of Faculty of Civil Engineering SUT in Bratislava, were designed so that the loss of stability occurs at the concrete strain about 1.5 ‰ on the compressed edge of a critical cross-section.

scholarly journals Direct Shocks in Vibrationally Nonequilibrium Diatomic Gases at Various Distances from Critical Cross-Section of Nozzle

2014 ◽  
Vol 11 (11) ◽  
pp. 1921-1926 ◽  
Author(s):  
Rydalevskaya Maria Alexandrovna ◽  
Voroshilova Yulia Nikolaevna ◽  
Uskov Vladimir Nikolaevich
Keyword(s):  
Cross Section ◽  
Critical Cross Section

Issues of Testing of Cementitious Composites in Uniaxial Tension

2016 ◽  
Vol 249 ◽  
pp. 85-90 ◽  
Author(s):  
Martin Tipka ◽  
Jitka Vašková
Keyword(s):  
Reinforced Concrete ◽  
Uniaxial Tension ◽  
Cross Section ◽  
Cementitious Composites ◽  
Critical Cross Section ◽  
Fibre Reinforced Concrete ◽  
Tension Tests ◽  
Before And After ◽  
Loading Methods

The paper deals with the issues of uniaxial tension tests of concrete and fibre reinforced concrete. Possible shapes of specimens and arrangements of the experiment are discussed, including the consequences arising from the adjustments. Behaviour of sample during loading, before and after initiation of the first crack is studied, stresses in the critical cross-section as well as loading methods are analysed.

scholarly journals Analysis of a Feder

2015 ◽  
Vol 2 (1) ◽  
pp. 255-274
Author(s):  
Ferenc Rádi
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Cross Section ◽  
Computer Analysis ◽  
Input Data ◽  
Real Life ◽  
Critical Cross Section ◽  
Analytical Mechanics ◽  
Computer Aided ◽  
The Cross

This paper covers an analysis in the cross section of sword fencing and the field of analytical mechanics and computer analysis. It aims to get answer to following questions in case of a normal blow with a feder on another feder: where are critical cross section/sections, where is the biggest stress, might the feder maybe break or not? To inspect this question a model for the feder was created in a reliable, realistic, simple and closed form. Modeling a single blow acceleration and speed state at the chosen time will be calculated. Based on this input data equations and conclusions from the analytical mechanics were applied, where D’Alamberts principle is used. Results will be validated by finite element computer aided modeling and also applied on specified real life cases.

Sign in / Sign up

Export Citation Format

Share Document