The method of averaging the gas flow parameters in turbomachines to evaluate their efficiency considering the velocity-field helicity

2019 ◽  
Vol 26 (2) ◽  
pp. 215-222 ◽  
Author(s):  
N. N. Kortikov
Keyword(s):  
Velocity Field ◽  
Gas Flow ◽  
Method Of Averaging ◽  
Flow Parameters

Modeling of pressure losses on friction in three-layer laminar flows

2003 ◽  
Vol 3 ◽  
pp. 208-219
Author(s):  
A.M. Ilyasov
Keyword(s):  
Pressure Loss ◽  
Gas Flow ◽  
Mutual Influence ◽  
Fluid Model ◽  
Immiscible Liquid ◽  
Laminar Flows ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Interphase Boundaries ◽  
Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

Simulation of mechanically stirred two-phase liquid-gas flow

1986 ◽  
Vol 51 (5) ◽  
pp. 1001-1015 ◽  
Author(s):  
Ivan Fořt ◽  
Vladimír Rogalewicz ◽  
Miroslav Richter
Keyword(s):  
Spatial Distribution ◽  
Velocity Field ◽  
Gas Flow ◽  
Liquid Velocity ◽  
Model Parameters ◽  
Two Phase ◽  
Mean Velocity ◽  
Rushton Turbine ◽  
Low Viscosity ◽  
Volumetric Gas Flow Rate

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.

scholarly journals Experimental Research of Gaseous Emissions Impact on the Performance of New-Design Cylindrical Multi-Channel Cyclone with Adjustable Half-Rings

2022 ◽  
Vol 14 (2) ◽  
pp. 902
Author(s):  
Aleksandras Chlebnikovas ◽  
Dainius Paliulis ◽  
Kristina Kilikevičienė ◽  
Artūras Kilikevičius
Keyword(s):  
Experimental Research ◽  
Gas Flow ◽  
Collection Efficiency ◽  
Fine Particulate Matter ◽  
Air Flow ◽  
Gaseous Emissions ◽  
Channel System ◽  
Flow Parameters ◽  
The Impact ◽  
Channel Type

Cyclones are widely used for separating particles from gas in energy production objects. The efficiency of conventional centrifugal air cleaning devices ranges from 85 to 90%, but the weakness of many cyclones is the low collection efficiency of particles less than 10 μm in diameter. The novelty of this work is the research of the channel-type treatment device, with few levels adapted for precipitation of fine particulate matter, acting by a centrifugal and filtration principle. Many factors have an impact on cyclone efficiency—humidity, temperature, gas (air) composition, airflow velocity and etc. Many scientists evaluated only the effect of origin and size of PM on cyclone efficiency. The effect of gas (air) composition and temperature, and humidity on the multi-channel cyclone-separator efficiency still demands contributions. Complex theoretical and experimental research on air flow parameters and the efficiency of a cylindrical eight-channel system with adjustable half-rings for removing fine-dispersive particles (<20 μm) was carried out. The impact of air humidity and temperature on air flow, and gaseous smoke components on the removal of wood ashes was analyzed. The dusty gas flow was regulated. During the experiment, the average velocity of the cyclone was 16 m/s, and the temperature was 20–50 °C. The current paper presents experimental research results of wood ash removal in an eight-channel cyclone and theoretical methodology for the calculation of airflow parameters and cyclone effectiveness.

scholarly journals Investigation of flow kinematics in the structured multibed catalytic cartridge

2019 ◽  
Vol 196 ◽  
pp. 00058
Author(s):  
Diana Ezendeeva ◽  
Sergei Kakaulin ◽  
Maxim Gordienko ◽  
Ivan Kabardin
Keyword(s):  
Volatile Organic Compounds ◽  
Velocity Field ◽  
Velocity Profile ◽  
Organic Compounds ◽  
Energy Efficient ◽  
Gas Flow ◽  
Laser Doppler Anemometry ◽  
Volatile Organic ◽  
Harmful Substances ◽  
Flow Distributor

The reduction of harmful substances emission into the atmosphere is very important to create compact, energy-efficient catalytic units for afterburning volatile organic compounds. A key component of such units is the catalyst cartridge. The efficiency of its operation is provided by the supply of a gas flow with a uniform velocity field. To solve the problem, the gas flow distributor and an aerodynamic stand for its testing were created. A set of air-flow blades was used to align the velocity profile before the catalyst cartridge. Also flow kinematics inside the cartridge was investigated via laser Doppler anemometry method.

scholarly journals Mathematical modeling of spatial gas flow in nozzles of nontrivial geometry

2021 ◽  
Vol 2094 (4) ◽  
pp. 042002
Author(s):  
S A Bitkin ◽  
M A Korepanov ◽  
M R Koroleva ◽  
A I Karpov ◽  
S S Makarov
Keyword(s):  
Gas Flow ◽  
Three Dimensional ◽  
Critical Section ◽  
Nozzle Geometry ◽  
Outlet Section ◽  
Flow Area ◽  
Flow Parameters ◽  
Inviscid Gas ◽  
Three Dimensional Models ◽  
The Mathematical Model

Abstract Numerical modeling of the spatial gas flow in an adjustable nozzle with an asymmetric critical section caused by the overlap of a part of the flow area by a gas flow regulator has been carried out. The mathematical model is based on three-dimensional models of gas dynamics, the method of large particles is used for calculation. When describing the unsteady flow of an inviscid gas, the system of Euler equations is used, written for a computational rectangular plane, taking into account the function of nozzle geometry. The results of calculations of flow parameters along a nozzle path with a uniform outlet section and with an obliquely cut outlet nozzle are presented. Calculations were carried out for completely open critical sections and for half overlapped. For oblique cut nozzles, the overlap of the critical section from the side of the short part and from the side of the long part of the oblique nozzle is considered.

scholarly journals Analysis of the impact of the labyrinth seal geometric parameters on the leakage

2021 ◽  
Vol 323 ◽  
pp. 00015
Author(s):  
Damian Joachimiak ◽  
Piotr Krzyślak
Keyword(s):  
Experimental Research ◽  
Gas Flow ◽  
Labyrinth Seal ◽  
Gas Pressure ◽  
Geometric Parameters ◽  
Labyrinth Seals ◽  
Flow Parameters ◽  
Number Of Teeth ◽  
The Impact ◽  
Size Data

This paper includes results of experimental research and CFD calculations concerning gas flow in segments of straight through labyrinth seals of fixed length and varying number of teeth. Relation between the number of teeth and the leakage is analyzed in this paper. Authors determined the range of teeth number for which the minimum leakage was achieved. They focused particularly on the analysis of geometry with maximum number of teeth which fell within the range of the minimum leakage. For this geometry they examined the relation between the thickness of the teeth and the distribution of gas pressure and velocity along the seal and the leakage size. Data presented in this paper indicate that the teeth thickness has a significant impact on the flow parameters.

Non-Equilibrium Relaxing Gas Flow Behind Three Dimensional Unsteady Curved Shock Wave

1980 ◽  
Vol 35 (11) ◽  
pp. 1166-1170
Author(s):  
V. D. Sharma ◽  
Radhe Shyam
Keyword(s):  
Shock Wave ◽  
Unsteady Flow ◽  
Gas Flow ◽  
Three Dimensional ◽  
Flow Conditions ◽  
Shock Surface ◽  
Flow Parameters ◽  
Upstream Flow ◽  
Relaxing Gas ◽  
Non Equilibrium

Abstract A shock wave is assumed to exist in a three-dimensional unsteady flow of a relaxing gas. The variation of flow parameters at any point behind the shock surface is determined in terms of the shock geometry and the upstream flow conditions. The expressions for the vorticity and the curvature of a streak line at the rear of the shock surface are also determined in terms of the known quantities.

Sign in / Sign up

Export Citation Format

Share Document