An Introduction to an Analysis of Gas Vibrations in Engine Manifolds

1947 ◽  
Vol 14 (3) ◽  
pp. A183-A187
Author(s):  
R. C. Binder ◽  
A. S. Hall
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Vibration Characteristics ◽  
Numerical Computations ◽  
Induction System

Abstract The performance of an internal-combustion engine may be influenced favorably or unfavorably by the vibration of the gas in the manifold. The analysis of this complicated action involves techniques which are not generally established nor widely known. This paper gives an introduction to these various techniques and their co-ordination. Included is a discussion of the vibration characteristics with damping for a tube, details as to numerical computations, and an outline of the analysis for a simple induction system.

Numerical Flow Simulation in the Induction System of an Internal Combustion Engine

1992 ◽  
Author(s):  
S. Y. Ho ◽  
A. J. Przekwas
Keyword(s):  
Internal Combustion Engine ◽  
Stokes Equations ◽  
Combustion Engine ◽  
Flow Simulation ◽  
Internal Combustion ◽  
Flow Fields ◽  
The Body ◽  
Design Parameters ◽  
Complex Flow ◽  
Induction System

Abstract An advanced computational fluid dynamics package, REFLEQS, has been adapted to calculate the flow in the induction system of an internal combustion engine. Results of complex flow fields in multi-valve engine intake/exhaust ports and cylinders, including moving valves and piston, are calculated. The body-fitted structured grids generated with partial differential equations method have been applied to represent complex engine components configuration such as engine intake/exhaust ports, ducts, valves and cylinders. An upwind scheme combined with SIMPLEC method is employed to solve the Navier-Stokes equations. Several 2D and 3D flows in engine ports/cylinders are simulated. Complex flow fields involve separated flows near the entry of cylinder head, vortices near the corner and behind the valves and the valve/stem generated swirling and tumbling flows. The present work aims at establishing a generalized computational environment for analyzing the physical mechanisms and design parameters controlling internal flows in automotive air/fuel induction systems.

Experimental Research on Plasma Discharge for Induction System of Internal Combustion Engine

2012 ◽  
Vol 516-517 ◽  
pp. 88-91
Author(s):  
Yu Han Zhao
Keyword(s):  
Internal Combustion Engine ◽  
Barrier Discharge ◽  
Combustion Engine ◽  
Effective Means ◽  
Internal Combustion ◽  
Plasma Discharge ◽  
Physical Parameters ◽  
Key Factors ◽  
Dielectric Barrier ◽  
Induction System

Ozone combustion-supporting is an effective means of internal combustion engine energy-saving. The theory of plasma method to produce ozone is mature, and how to improve the efficiency of ozone reaction becomes the key point. The chemical reaction process under the conditions of plasma involves the physical parameters and problems of gas discharge. Withal, research on the DBD (dielectric barrier discharge) experiments is carried on. And the key factors of improving the efficiency of the reaction, such as the physical parameters of discharge uniformity and the discharge power, are examined.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

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