arXiv subjects

Y. P. Sirik

Publications and source records attributed to Y. P. Sirik.

9 recordsLinked to original sources

arXiv2005

Laval Turbonozzle Dynamics

The results of computing experiments are presented for the steam and gas stream motion in converging-diverging flow element called Laval nozzle and applied in steam and gas turbines. In beginning the experiments had carried out for Laval nozzle tested by Stodola and then for this turbonozzle various modifications. Quantitative evaluation of the state and motion parameters of the viscous compressible fluid and the metering characteristics of the flow elements are given as well as physically adequate interpretation of the obtained results is presented at the first time. The computing experiments are carried out by means of VeriGas program-modeler composed on the base of a new approach to the classical physics development in field of fluid motion.

physics.flu-dyn↗

arXiv2003

The Gasdynamics First Problem Solution. The Gas Stream Parameters, Structures, Metering Characteristics for Pipe, Nozzle

The development of the classical physics fundamentals with usage of experience of the experimental and computational-analytical investigations has allowed to create the valid conception of a fluid motion. The multidisciplinary approach on a new basis has allowed to ensure the physical adequacy to a mathematical model of the gas flow with allowance for essential nonlinearity of change of the gas stream main parameters and the metering characteristics of the flow elements of the type: pipe, pipeline, convergent nozzle and also with allowance for the evolutional character of the gas flow structure before a setting, in the itself flow element and in jet flowing out from one. The example of the valid solution of the direct and inverse problems about a gas flow through the flow element is given for the first time. The results of the solution by amount, kind and precision of the obtained information are an example of the satisfactory solution of the gas dynamics problem.

physics.flu-dyn↗

arXiv2003

The boundary and continual transfer phenomena in fluids and flows

The clearing up of a wave nature of the energy and mass transfer phenomena in classical expressions of the molecular-kinetic theory has allowed to find a quantitative measure of intensity of processes of a thermal conductivity, viscosity and diffusion in conditions of a thermally nonequilibrium and heterogeneous composition continuum. It is rotined that the appearance of a temperature drop in fluid stipulates the appearance of the continuum stratification and formation of the flowing bodies interacting among themselves. It is rotined that the known expressions for a thermal conductivity, viscosity, diffusion and heat convection had been obtained for a thermally equilibrium and homogeneous continuum and produce a maximum quantity of intensity of the transfer processes. The introduced expression is usable for a quantitative estimation of intensity of the transfer processes in fluid and its streams in conditions of the non-stationary heat exchange in natural conditions and technical problems.

physics.flu-dyn↗

arXiv2003

The laminar flow instability criterion and turbulence in pipe

The identification of stream in the straight pipe as a flexible rod has allowed to present the criterion expression for determination of transition of the laminar flow regime to the turbulent as a loss of stability of the rectilinear static structure of translational motion of stream in pipe and its transition to the flexural-vortical dynamic structure of translational motion, just as a flexible rod buckling. The introduced criterion allows to take into account an influencing of the inlet geometry, the pipe length, the flow velocity, and also of any physical factors on stability of the rectilinear flow structure. It is ascertained, that Reynolds number is the number of local hydrodynamic similarity and it is displayed that one is constituent part of the introduced stability criterion. The developed approach to a problem of stability is applicable for a problem solving on internal flow and external streamline.

physics.flu-dyn↗

arXiv2003

The gas equation for stream

The equation of state for gas stream as analog of well-known equation of state of gas medium in the static conditions is submitted. The connection of parameters of state and motion, and also the volume-flow rate and the mass-flow rate of the gas stream during change of its temperature and pressure as the result of external action is shown on example of modification of the represented equation.

physics.flu-dyn↗

arXiv2003

The Flowing System Gasdynamics Part 4: Influence of the incident flow velocity on the outflow velocity out of flowing eleme

It is shown, that the introduction in Saint-Venant -Wantzel formula radicand of the free component in the form of quadrate of velocity of the incident gas flow on inlet of flowing element that was offered in the end of the XIX century and is remained till now it is physically inadequate. It is shown that this way is doubtful for hydromechanics and it absolutely is not reasonably for gasdynamics. Physically exact form of writing of static head law for flowing element and relevant to this, the modern form of Saint-Venant - Wantzel formula are submitted ad-hoc. The obtained expressions allow physically correctly to take into account both combined and isolated influence of pressure drop applying to the flowing element and velocity of incident gas flow on flowing element, on quantity of the outflow velocity of gas stream out of this flowing element, system. The obtained expressions are valid for a subsonic velocity of the incident gas flow. The particular expressions are obtained for liquid.

physics.flu-dyn↗

arXiv2003

The Flowing System Gasdynamics. Part 3: Saint-Venant - Wantzel formula modern form

The modern form of the Saint-Venant - Wantzel formula for an outflow velocity of gas stream from flowing element is submitted. Taking into account of contact interaction of gas stream with the streamline surface in the form of the static head law has allowed to find the spatial-energy liaison in flowing system. The physically correct combination of mechanics of contact interaction and thermodynamics of fluid medium in one formula has allowed simultaneously to be liberated from the velocity coefficient and the discharge coefficient and polytropic process. In the new form the formula has gained the key character for computation of parameters of motion and state of gas stream in the flowing system.

physics.flu-dyn↗

arXiv2003

The Flowing System Gasdynamics Part 2: Euler momentum conservation equation solution

The solution of a momentum conservation equation for the gas and liquid stream in the flowing element is obtained on the basis of the modern approach to a problem on contact interaction of bodies and mediums. A flowing element, system are: pipe, tube, orifice, mouthpiece, diffuser, etc. and its combination. The integration of the differential equation has reduced to distribution law of static head along the length of flowing element and has proved the elementary algebraic solution that introduced in the previous paper by these authors. The received solution allows to describe the motion of fluid medium in non-stationary conditions, under action of any time-varying physical factors: a roughness of streamlined surface, the area of the section of the flowing element, the heat exchange with the streamlined surface, the technical work, the additional weight flow of fluid medium.

physics.flu-dyn↗

arXiv2003

The Flowing System Gasdynamics Part 1: On static head in the pipe flowing element

The solution of problem on distribution of static head along the pipe flowing element is submitted. The solution is reached on the basis of consideration of contact interaction of gas and liquid stream with the wall of the pipe flowing element. The expression for distribution of static head along the pipe flowing element is obtained on the basis of usage of three fundamental laws in fluid dynamics: Torricelli formula, Weissbach-Darcy formula and Bernoulli equation. The general solution is obtained for a gas stream. The special case of the obtained solution is retrieved for liquid stream.

physics.flu-dyn↗