The Solution of Boundary Value Problems of Various Types with Consideration of Volume Forces for Anisotropic Bodies of Revolution

2021 ◽  
pp. 57-70
Author(s):  
D.A. Ivanychev ◽  
E.Yu. Levina
Keyword(s):  
Elastic Equilibrium ◽  
Transversely Isotropic ◽  
The Body ◽  
Bodies Of Revolution ◽  
State Spaces ◽  
Elastic Fields ◽  
Boundary State ◽  
Boundary States ◽  
Anisotropic Bodies ◽  
The Given

In this work, we studied the axisymmetric elastic equilibrium of transversely isotropic bodies of revolution, which are simultaneously under the influence of surface and volume forces. The construction of the stress-strain state is carried out by means of the boundary state method. The method is based on the concepts of internal and boundary states conjugated by an isomorphism. The bases of state spaces are formed, orthonormalized, and the desired state is expanded in a series of elements of the orthonormal basis. The Fourier coefficients, which are quadratures, are calculated. In this work, we propose a method for forming bases of spaces of internal and boundary states, assigning a scalar product and forming a system of equations that allows one to determine the elastic state of anisotropic bodies. The peculiarity of the solution is that the obtained stresses simultaneously satisfy the conditions both on the boundary of the body and inside the region (volume forces), and they are not a simple superposition of elastic fields. Methods are presented for solving the first and second main problems of mechanics, the contact problem without friction and the main mixed problem of the elasticity theory for transversely isotropic finite solids of revolution that are simultaneously under the influence of volume forces. The given forces are distributed axisymmetrically with respect to the geometric axis of rotation. The solution of the first main problem for a non-canonical body of revolution is given, an analysis of accuracy is carried out and a graphic illustration of the result is given

A BOUNDARY STATE METHOD FOR SOLVING A MIXED PROBLEM OF THE THEORY OF ANISOTROPIC ELASTICITY WITH MASS FORCES

2021 ◽  
pp. 63-77
Author(s):  
D.A. Ivanychev ◽  
Keyword(s):  
Mixed Problem ◽  
Strain State ◽  
The Body ◽  
Stress Strain ◽  
Boundary Points ◽  
Stress Strain State ◽  
Boundary State ◽  
Boundary States ◽  
State Method

The paper presents a methodology for determining a stress-strain state of transversely isotropic bodies of revolution under conditions of a mixed problem of the elasticity theory, i.e. displacements of the boundary points are specified on the one part of the surface, and forces are assigned on the other part. At the same time, the body is exposed to mass forces. The problem solving involves the development of the boundary state method. A theory is created to construct the bases of spaces for internal and boundary states. The basis of the internal states includes displacements, strains, and stresses. The basis of the boundary states includes forces at the boundary, displacements of the boundary points, and mass forces. Spaces are conjugated by an isomorphism. It allows one to reduce the determination of the internal state to a study of the boundary state. Characteristics of the stress-strain state are presented in terms of the Fourier series. Finally, the determination of the elastic state is reduced to the solving of an infinite system of algebraic equations. A result of the study is presented as a solution to the main mixed problem for a hemisphere clamped on a plane surface and exposed to a concentrated compressive force and mass forces.

PENGEMBANGAN TANAMAN RAMI (Boehmeria nivea L. Gaud) DAN PEMANFAATAN LIMBAH DAUN RAMI UNTUK PENGGEMUKKAN DOMBA WONOSOBO

2018 ◽  
Vol 16 (2) ◽  
pp. 201-210
Author(s):  
Muryanto Muryanto ◽  
Pita Sudrajad ◽  
Amrih Prasetyo
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Plant Development ◽  
Body Weight Gain ◽  
Survey Methods ◽  
The Body ◽  
Boehmeria Nivea ◽  
Central Java ◽  
Potential Capacity ◽  
The Given

The aim of the study was to determine the development of ramie plants (Boehmeria nivea L. Gaud) and the effect of using ramie leaves on feed on the body weight gain of Wonosobo Sheep (Dombos). Research on the development of ramie plants using survey methods in the area of ramie plant development in Wonosobo Regency. While the research on the use of ramie leaves for fattening was carried out in Butuh Village, Kalikajar District, Wonosobo Regency in 2018. 21 male Dombos were divided into 3 feed treatments with forage proportions of 70%, 50% and 30 ramie leaves respectively. %. The results showed that currently ramie plants were being developed in Wonosobo Regency by CV. Ramindo Berkah Persada Sejahtera in Gandok Village, Kalikajar District, Wonosobo Regency, Central Java. Until now the area of the crop has reached 13 ha. Of this area will produce ramie leaves 195,000 kg / year. If one sheep needs 4 kg of ramie / tail / day leaves, then the potential capacity of sheep is 135 heads / year, if the given one is 50% then the Jurnal Litbang Provinsi Jawa Tengah, Volume 16 202 Nomor 2 – Desember 2018potential capacity is 270 heads / year and if it is reduced again to 25% of ramie leaves then the potential capacity 440 heads / year. The use of ramie leaves as a feed for Wonosobo Sheep fattening can be given as much as 30% in fresh form.

Numerical modelling of swirling momentumless turbulent wake dynamics

2018 ◽  
pp. 37-48
Author(s):  
Андрей Геннадьевич Деменков ◽  
Геннадий Георгиевич Черных
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Mathematical Models ◽  
Equations Of Motion ◽  
Turbulent Wake ◽  
The Body ◽  
Jet Flows ◽  
Reynolds Stresses ◽  
Bodies Of Revolution ◽  
Averaged Equations

С применением математической модели, включающей осредненные уравнения движения и дифференциальные уравнения переноса нормальных рейнольдсовых напряжений и скорости диссипации, выполнено численное моделирование эволюции безымпульсного закрученного турбулентного следа с ненулевым моментом количества движения за телом вращения. Получено, что начиная с расстояний порядка 1000 диаметров от тела течение становится автомодельным. На основе анализа результатов численных экспериментов построены упрощенные математические модели дальнего следа. Swirling turbulent jet flows are of interest in connection with the design and development of various energy and chemical-technological devices as well as both study of flow around bodies and solving problems of environmental hydrodynamics, etc. An interesting example of such a flow is a swirling turbulent wake behind bodies of revolution. Analysis of the known works on the numerical simulation of swirling turbulent wakes behind bodies of revolution indicates lack of knowledge on the dynamics of the momentumless swirling turbulent wake. A special case of the motion of a body with a propulsor whose thrust compensates the swirl is studied, but there is a nonzero integral swirl in the flow. In previous works with the participation of the authors, a numerical simulation of the initial stage of the evolution of a swirling momentumless turbulent wake based on a hierarchy of second-order mathematical models was performed. It is shown that a satisfactory agreement of the results of calculations with the available experimental data is possible only with the use of a mathematical model that includes the averaged equations of motion and differential equations for the transfer of normal Reynolds stresses along the rate of dissipation. In the present work, based on the above mentioned mathematical model, a numerical simulation of the evolution of a far momentumless swirling turbulent wake with a nonzero angular momentum behind the body of revolution is performed. It is shown that starting from distances of the order of 1000 diameters from the body the flow becomes self-similar. Based on the analysis of the results of numerical experiments, simplified mathematical models of the far wake are constructed. The authors dedicate this work to the blessed memory of Vladimir Alekseevich Kostomakha.

Body Temperature of the Camel and Its Relation to Water Economy

1956 ◽  
Vol 188 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Knut Schmidt-Nielsen ◽  
Bodil Schmidt-Nielsen ◽  
S. A. Jarnum ◽  
T. R. Houpt
Keyword(s):  
Body Temperature ◽  
Water Conservation ◽  
Skin Surface ◽  
Diurnal Variations ◽  
The Body ◽  
Free Access ◽  
Heat Gain ◽  
Hot Environment ◽  
Access To Water ◽  
The Given

The rectal temperature of normal healthy camels at rest may vary from about 34°C to more than 40°C. Diurnal variations in the winter are usually in the order of 2°C. In summer the diurnal variations in the camel deprived of drinking water may exceed 6°C, but in animals with free access to water the variations are similar to those found in the winter. The variations in temperature are of great significance in water conservation in two ways. a) The increase in body temperature means that heat is stored in the body instead of being dissipated by evaporation of water. At night the excess heat can be given off without expenditure of water. b) The high body temperature means that heat gain from the hot environment is reduced because the temperature gradient is reduced. The effect of the increased body temperature on heat gain from the environment has been calculated from data on water expenditure. These calculations show that under the given conditions the variations in body temperature effect a considerable economy of water expenditure. The evaporative heat regulation in the camel seems to rest exclusively on evaporation from the skin surface (sweating), and there is no apparent increase in respiratory rate or panting connected with heat regulation. The evaporation from isolated skin areas increases linearly with increased heat load. The critical temperature at which the increase sets in is around 35°C. The fur of the camel is an efficient barrier against heat gain from the environment. Water expenditure is increased in camels that have been shorn.

scholarly journals Ultrasonography in diagnosis of sexual development delay of girls and teenagers having diabetes mellitus of the 1st type

2002 ◽  
Vol 1 (4) ◽  
pp. 87-92
Author(s):  
N. M. Kondratyeva ◽  
V. D. Zavadovskaya ◽  
E. B. Kravets ◽  
E. V. Gorbatenko ◽  
L. S. Strelis
Keyword(s):  
Diabetes Mellitus ◽  
Blood Flow ◽  
Sexual Development ◽  
The Body ◽  
Ultrasound Studies ◽  
Ultrasound Study ◽  
Development Delay ◽  
The Given ◽  
Ultrasound Classification

Girls-teenagers (n = 85) aged from 8 to 18 years having diabetes mellitus (DM) of the 1st type were investigated using ultrasonography method. Based upon decreasing and disproportion of the body and neck of the uterus, changed Mecho thickness and ovaries structure, different parameter of blood flow, we worked out classification of the four stages of sexual development delay (SDD) (0 stage in 15 girls, I stage in 26 girls, II stage in 20 girls and III stage in 21 girls). Comparative analysis of clinical and ultrasound studies showed the advantage of ultrasound study to assess status of internal genital organs in girls and teenagers having DM. Investigation performed based upon E. Tanner classification revealed SDD 40 girls, bimanual examination in 45 girls, sonography method — in 82 girls. The given ultrasound classification of sexual development delay in girls-teenagers having DM of the 1st type contributes to diagnosis and prescribing timely effective correction therapy.

Positioning Effect on Free Convection with an Elliptical Plate Placed in a Circular Enclosure

2020 ◽  
Vol 12 (8) ◽  
pp. 1054-1062
Author(s):  
Parth Patpatiya ◽  
Soumya ◽  
Bhavya Shaan ◽  
Bhavana Yadav
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
The Body ◽  
Elliptical Plate ◽  
Numerical Studies ◽  
First Case ◽  
Varied Temperature ◽  
Laminar Natural Convection ◽  
The Given ◽  
Plate System

In this analysis we have examined the process of the steady state laminar natural convection around heated elliptical plate with Rayleigh number 10^6 positioned inside a circular enclosure. The purpose of the numerical analysis is to analyze the behavior of isotherms, streamlines and heat transfer rate in enclosure plate system due to the variation in the position of elliptical plate (r/D =0.00, 0.05, and 0.2) and aspect ratio, where the given diameter of the enclosure is D and r is the distance between the centre of elliptical plate and centre of circle. Elliptical plate is inclined at different angles and results are summed up in relative manner. There are two cases, in first case aspect ratio a/D and b/D is varied and D is kept constant, whereas in second case aspect ratio a/D and b/D is kept constant and D is varied. Temperature difference between the enclosure and the inner body (i.e., temperature of inner body is kept high as compared to the enclosure) is maintained. Two dimensional study is followed by considering air as a fluid in enclosure. The effects of the Heat Transfer and Flow of Fluid are analyzed by the streamlines and isotherms plotted for the body placed inside enclosure. Value of local Nusselt number (Nu) is also plotted along the wall of elliptical plate and along the surface of the circular enclosure. For every aspect ratio isotherms and streamlines had been plotted. This work has been validated with various other numerical studies and was in good conciliation.

A System to Measure Turbulent Lengthscales on Submerged Bodies of Revolution

2017 ◽  
Author(s):  
Christopher J. Chesnakas ◽  
Daniel R. Cadel
Keyword(s):  
Laser Doppler Velocimetry ◽  
Arrival Time ◽  
Noise Removal ◽  
The Body ◽  
Doppler Velocimetry ◽  
Body Of Revolution ◽  
Sampled Data ◽  
Bodies Of Revolution ◽  
Submerged Body ◽  
Cross Correlations

A system has been developed to measure the turbulent lengthscales in the flow about a submerged body of revolution. The system consists of two Laser Doppler Velocimetry (LDV) probes mounted inside the body of revolution with the beams projected outside of the body through conformal windows. The measurement volumes of the two probes can be independently positioned within a plane perpendicular to the body axis. The probes are used to measure velocity time series at various spacings in the flow field. Auto- and cross-correlations are computed for each measurement pair, from which integral lengthscales are then found. Measurements are compared to canonical data from a turbulent free shear jet. In this paper, the system is described and its theory of operation detailed. Methods of computing the velocity correlations from the random-arrival-time LDV measurements are presented, and a new noise-removal scheme for non-uniformly sampled data is introduced. Six methods for calculating the integral lengthscale from autocorrelation data are reviewed, and the results discussed for the present jet data measured with LDV.

A Comparison of Theoretical and Experimental Pressure Distributions on Bodies of Revolution

1980 ◽  
Vol 24 (01) ◽  
pp. 60-65
Author(s):  
A. J. Smits ◽  
S. P. Law ◽  
P. N. Joubert
Keyword(s):  
Calculation Method ◽  
The Body ◽  
Viscous Effects ◽  
Bodies Of Revolution ◽  
Pressure Distributions ◽  
Wide Range ◽  
The Right ◽  
Right Order ◽  
Axisymmetric Bodies ◽  
Experimental Pressure

A wide range of experimental pressure distributions along axisymmetric bodies was compared with the results of Landweber's potential flow calculation method. Apart from certain viscous effects, some discrepancies were found, and it is shown that blockage corrections are of the right order to account for these discrepancies. The calculation method was also used to show that the pressure distribution over the nose of the body is largely independent of the tail shape, and vice versa.

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