scholarly journals Spectral analysis of gas-dynamic processes in the intake system of a supercharged piston engine

2020 ◽  
Vol 1565 ◽  
pp. 012006
Author(s):  
L V Plotnikov ◽  
N S Kochev ◽  
L E Osipov
Keyword(s):  
Spectral Analysis ◽  
Dynamic Processes ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic

scholarly journals Spectral analysis of gas dynamic processes in the inlet system of a piston engine with turbocharger

2021 ◽  
Vol 23 (4) ◽  
pp. 43-54
Author(s):  
L. V. Plotnikov ◽  
Y. M. Brodov ◽  
B. P. Zhilkin ◽  
D. S. Shestakov ◽  
L. E. Osipov
Keyword(s):  
Spectral Analysis ◽  
Comparative Analysis ◽  
Flow Velocity ◽  
Pressure Pulsations ◽  
Piston Engine ◽  
Outlet Channel ◽  
Inlet System ◽  
Operating Cycle ◽  
Intake System ◽  
Gas Dynamic

THE PURPOSE. To carry out a comparative analysis of the spectra of gas-dynamic characteristics of flows in the intake systems of piston engines with and without turbocharging, to assess the degree of influence of the turbocharger on the flow structure in such systems, and also to propose a method for the gas-dynamic improvement of processes in the system under consideration. METHODS. Due to the complexity of the object of research, an experimental approach was taken as a basis. The experiments were carried out on a single-cylinder piston engine model, which could be equipped with a turbocharger. A system for collecting and processing experimental data based on an analog-to-digital converter was used in the study. Data on changes in local values of velocity and static pressure of pulsating flows in the intake system during the engine's operating cycle were obtained using a constant temperature hot-wire anemometer and a fast-acting pressure sensor. Spectral analysis of functions of flow velocity and pressure versus time was carried out on the basis of the fast Fourier transform algorithm.RESULTS. The article presents a comparative analysis of the spectra of the amplitudes of the velocity and pressure pulsations in the intake system of an engine with and without turbocharging. Also proposed is a method for stabilizing the pulsating flow in the intake system by installing a leveling grid in the outlet channel of the turbocharger compressor. CONCLUSION. It is shown that the installation of a turbocharger leads to a significant change in the structure of gas flows in the intake system of the engine. It has been established that the presence of a leveling grid in the intake system of a turbocharged piston engine leads to a decrease in the low-frequency amplitudes of the flow velocity and pressure pulsations up to 30%. It is shown that the probability of failure-free operation of an automobile engine (cylinder diameter – 82 mm, piston stroke – 71 mm) increases by almost 1% when a leveling grille is used in the intake system.

Thermal and mechanical improvement of the air supply system of a turbocharged piston engine

2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Local Heat Transfer ◽  
Supply System ◽  
Scale Model ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic ◽  
Air Supply ◽  
Air Flows

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.

Improvement of the Operating Processes in Boiler Furnaces of TÉTs-21 with the Help of Numerical Simulation of Thermal Gas Dynamic Processes

2003 ◽  
Vol 37 (5) ◽  
pp. 297-301
Author(s):  
A. P. Tishin ◽  
I. T. Goryunov ◽  
Yu. L. Gus'kov ◽  
D. A. Barshak ◽  
G. V. Presnov ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dynamic Processes ◽  
Gas Dynamic

PHYSICAL PREREQUISITES FOR GAS PERMEABILITY SIMULATION OF MINED ROCK MASS

2021 ◽  
pp. 78-84
Author(s):  
Oleksandr Shashenko ◽  
◽  
Vladyslava Cherednyk ◽  
Natalia Khoziaikina ◽  
Dmitro Shashenko ◽  
...  
Keyword(s):  
Rock Mass ◽  
Physical Model ◽  
Rock Sample ◽  
Coal Mass ◽  
Dynamic Processes ◽  
Deformation Diagram ◽  
Gas Dynamic ◽  
Laboratory Test Results ◽  
Deformation Properties ◽  
Complete Deformation

Purpose. Justification of the gas collectors formation physical model on the basis of research of conformity of permeability of rock mass to the full diagram of rock sample deformation. Methodology consists in sequential analysis of the stages of the complete deformation diagram of the rock specimen under “hard” loading, comparing them with the stages of formation of the high stress zone in front of the lava bottom and statistical analysis of laboratory test results. Results. Based on the rock’s deformation properties analysis and their comparison with the rock sample full deformation diagram, the physical model of formation of gas reservoirs during the development of gas-saturated coal seam is substantiated. Within the solved problem framework, four stages of the complete deformation process are analyzed, namely: elastic, at the limit of strength, out-of-bounds stage and equivoluminal flow zone. The gas collector boundaries, which are the characteristic points of the rock sample deformation diagram in specified deformations mode (the limit of elastic strength and the limit of final strength) are determined. It is proved that the structural and textural features of the coal mass in connection with the course of gas-dynamic processes are manifested in the change in the pores and cracks volume contained in it, which together make the filtration space. Knowledge regarding the transfer of the permeability changes established regularities and free methane accumulation zones formation to the real rock mass, if the process of its forgery is considered as a consistent change of geomechanical states of rocks, is obtained. Scientific novelty lies in the first substantiated possibility of modeling the stress state before the longwall face by equivalent stages of the rock sample destruction in the given deformations mode. Gradual comparative analysis of the internal mechanism of rock samples deformation along the complete deformation diagram allowed establishing causal relationships between geomechanical and gas-dynamic processes in coal mass, and qualitatively characterizing general trends in permeability and volumetric expansion in changes of these samples. Practical value of the work lies in the justification of the principle of construction of a digital geomechanical model for the detection of man-made gas collectors in a mined coal mass.

scholarly journals Investigation of strength of shaped elements of the main gas pipeline

2019 ◽  
Vol 6 (1) ◽  
pp. 14-21
Author(s):  
Ya.V. Doroshenko
Keyword(s):  
Stressed State ◽  
Temperature Difference ◽  
Three Dimensional ◽  
Gas Pipeline ◽  
Cfd Modeling ◽  
Dynamic Processes ◽  
Internal Cavity ◽  
Main Stream ◽  
Gas Dynamic ◽  
Main Gas Pipeline

The research has been carried out for the purpose of a complex numerical three-dimensional modeling of the stressed state of taps and tees of main gas pipelines taking into account the gas-dynamic processes occurring in these shaped elements and the temperature difference in their walls. A 3D modeling of the elbow with a 90° angle and a reinforcing pad on the main line and the drainage of the passage line of the trunk of the main gas pipeline has been carried out. There has been studied the gas flow with 3D models of shaped elements of the main gas pipeline by means of the CFD modeling. The simulation has been рerformed for the equidistant tees in which the entire flow from the main stream flows into its branch. The mathematical model is based on the solution of the Navier–Stokes equation system, continuity equation, closed by a two-parametric k -e model of the Launder–Sharma turbulence with corresponding initial and boundary conditions. The simulation results are visualized in the ANSYS Fluent R18.2 Academic Postprocessor by constructing the pressure fields on the contours and in the longitudinal and transverse sections of shaped elements. The exact values of pressure at different points of the inner cavity of the shaped elements have been determined, the places of rise and fall of pressure identified. There have been performed the simulation of the temperature difference in the walls of the drainage, the trunk of the main gas pipeline in the module ANSYS Transient Thermal. The results of CFD and temperature modeling were imported into the mechanical module ANSYS Static Structural, where the finite element method was used to simulate the stressed state of the shaped elements of the main gas pipeline, taking into account the gas-dynamic processes occurring in their internal cavity and the temperature difference in the walls. The results of the simulation have been visualized by constructing a three-dimensional color fields of equivalent von Mises stresses in the tee and in the elbow. The places of the maximum equivalent stresses in the wall of the studied shaped elements have been revealed. 

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