The article is devoted to studying the contra-rotating stages with different impellers and blade discs. Determining reduction of volumetric losses by modeling in software package ANSYS CFX. work aimed create study flow characteristics: semi-open, closed impellers, As a result work, following were determined compared: semi-opened impeller disc; disc. research, fluid flows their characteristics f...

Creep response in a rotating disc made of anisotropic Al-SiC(particle) composite having linearly varying thickness has been carried out using anisotropic Hoffman yield criterion in present study. The steady state creep behavior is described by Sherby’s constitutive model. The material parameters characterizing difference in yield stresses have been used from the available experimental results i...

Centrifugal pressure of matter spiralling onto black holes, have long been known to produce standing or oscillating shocks. The post-shock disc puffs up in the form of a torus, which intercepts soft photons from the outer Keplerian disc and inverse Comptonizes them to produce hard photons. The post-shock region also produces jets. We study the interaction of both hard photons and soft photons, ...

We use three dimensional magnetohydrodynamic simulations to study the structure of the boundary layer between an accretion disc and a non-rotating, unmagnetized star. Under the assumption that cooling is efficient, we obtain a narrow but highly variable transition region in which the radial velocity is only a small fraction of the sound speed. A large fraction of the energy dissipation occurs i...

We calculate the structure of accretion disc around a rapidly rotating black hole with a super-Eddington accretion rate. The luminosity and height of the disc are reduced by the advection effect. In the case of a large viscosity parameter, α > 0.03, the accretion flow strongly deviates from thermodynamic equilibrium and overheats in the central region. With increasing accretion rate, the flow t...

We present VLBI observations of 6.7 and 12.2 GHz methanol masers in the star forming region NGC7538. Our results show the existence of two groups of masers. The first group exhibits a linear velocity gradient and forms a line in our VLBI map which is consistent with a rotating disc of masers seen edge-on around a massive star. The second group of masers are blueshifted with respect to the first...

A prescription for the density of a wind compressed disc (WCD) is given and the IRemissionof the disc is calculated. The prescription enables emission fromWCDs to be calculated simply without recourse to full 2 1 2 -dimensional (2 1 2 -D) modelling of rotating radiatively driven winds. It is shown that the standard WCD model is incapable of representing observed Be star discs. As a guide for fu...

In this work the most spectacular phenomena occurring during the formation of a star are briefly reviewed: accretion through a rotating disc of matter and outflow through the poles of the new stellar object. Magnetic fields have been proposed to be principally responsible for the coexistence of these opposed mechanisms of accretion and outflowing. According to different models, the magnetic fie...

Our aim is to study the evolution of the orbit of a star under the influence of interactions with an accretion disc in an AGN. The model considered consists of a low-mass compact object orbiting a supermassive black hole and colliding periodically with the accretion disc. Approximate calculations based mostly on Newtonian theory of gravity have been carried out by several authors to estimate th...