scholarly journals Vibroacoustic methods of assessing valve clearance in combustion engines* An analysis of signals in the area of frequency

2010 ◽  
Vol 142 (3) ◽  
pp. 76-81
Author(s):  
Grzegorz Szymański ◽  
Franciszek Tomaszewski
Keyword(s):  
Combustion Engine ◽  
Frequency Characteristics ◽  
Combustion Engines

This article presents results of research referring to applying selected frequency characteristics of signal of vibration accelerations of combustion engine’s head to assess valve clearance of combustion engine. The authors indicate necessity to perform preliminary preparations of signal of vibration accelerations before carrying out frequency analyses in order to decrease the risk of inaccurate analysis.

The Use of Short-Term Compressed Air Supercharging in a Combustion Engine with Spark Ignition

2021 ◽  
Vol 18 (2) ◽  
pp. 8704-8713
Author(s):  
Jarosław Janusz Mamala ◽  
K. Praznowski ◽  
S. Kołodziej ◽  
G. Ligus
Keyword(s):  
Driving Force ◽  
Negative Impact ◽  
Combustion Engine ◽  
Spark Ignition ◽  
Compressed Air ◽  
Acceleration Process ◽  
Combustion Engines ◽  
Short Term ◽  
Drive Unit ◽  
The People

The powertrain is a very important subassembly in a car and is responsible not only for the automotive industry’s impact on the environment but also for the safety of people travelling by car and performing overtaking manoeuvres and joining traffic. In general, the powertrain is a combination of the drive unit and drive transmission, wherein the drive unit is responsible for the available driving force in the car’s wheels and for the car’s ability to accelerate when the throttle pedal is rapidly pressed at a constant gearbox ratio. The availability of the driving force reserve in the powertrain is the most important issue for the reason of safety of the people travelling by car. In the case of drive unit what they are of the combustion engines, the rapid pressing of the throttle pedal in the car acceleration process leads to a temporary deficiency in the driving force and in the powertrain’s output. The deficiency in the driving force has a negative impact on acceleration and driving comfort. In this paper, the authors assessed and analysed two different short-term compressed air supercharging systems for combustion engines with air supplied from a high-pressure tank. The analysis covered the response of the combustion engine with spark ignition to the gradual increase in pressure in the air-intake system. The assumption is that the applied short-term compressed air supercharging system could improve the driving force during the phase of the engine’s increasing crankshaft rotational speed. This helps to achieve the improved passenger car acceleration dynamics, depending on the supercharging method and throttle pedal exertion. When analysing the car’s acceleration dynamics, expressed by the shorter time of increasing the longitudinal speed from initial to final, it was possible to shorten the acceleration time. It is also possible to observe an improved driving force behaviour, especially during the first phase of acceleration.

Investigating Fuel Condensation Processes in Low Temperature Combustion Engines

2014 ◽  
Author(s):  
Lu Qiu ◽  
Rolf D. Reitz
Keyword(s):  
Low Temperature ◽  
Combustion Engine ◽  
Phase Region ◽  
Low Temperature Combustion ◽  
Combustion Engines ◽  
Two Phase ◽  
Temperature Combustion ◽  
Real Gas Effects ◽  
Unburned Hydrocarbons ◽  
Late Stages

Condensation of gaseous fuel is investigated in a low temperature combustion engine fueled with double direct-injected diesel and premixed gasoline at two load conditions. Possible condensation is examined by considering real gas effects with the Peng-Robinson equation of state and assuming thermodynamic equilibrium of the two fuels. The simulations show that three representative condensation events are observed. The first two condensations are found in the spray some time after the two direct injections, when the evaporative cooling reduces the local temperature until phase separation occurs. The third condensation event occurs during the late stages of the expansion stroke, during which the continuous expansion sends the local fluid into the two-phase region again. Condensation was not found to greatly affect global parameters, such as the average cylinder pressure and temperature mainly because, before the main combustion event, the condensed phase was converted back to the vapor phase due to compression and/or first stage heat release. However, condensed fuel is shown to affect the emission predictions, including engine-out particulate matter and unburned hydrocarbons.

scholarly journals THE COMBUSTION ENGINE INTAKE MANIFOLD CFD MODELING DEPENDING ON THE AIRBOX CONFIGURATION

2021 ◽  
Vol 2021 (6) ◽  
pp. 5421-5425
Author(s):  
MICHAL RICHTAR ◽  
◽  
PETRA MUCKOVA ◽  
JAN FAMFULIK ◽  
JAKUB SMIRAUS ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Stationary Flow ◽  
Cfd Modeling ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Computational Fluid Dynamics Cfd

The aim of the article is to present the possibilities of application of computational fluid dynamics (CFD) to modelling of air flow in combustion engine intake manifold depending on airbox configuration. The non-stationary flow occurs in internal combustion engines. This is a specific type of flow characterized by the fact that the variables depend not only on the position but also on the time. The intake manifold dimension and geometry strongly effects intake air amount. The basic target goal is to investigate how the intake trumpet position in the airbox impacts the filling of the combustion chamber. Furthermore, the effect of different distances between the trumpet neck and the airbox wall in this paper will be compared.

scholarly journals Fault analysis of the combustion engine used in public transport vehicles

2018 ◽  
Vol 189 (3) ◽  
pp. 95-108
Author(s):  
Pawel Drozdziel ◽  
Iwona Rybicka ◽  
Slawomir Tarkowski
Keyword(s):  
Public Transport ◽  
Combustion Engine ◽  
Fault Analysis ◽  
Annual Number ◽  
Repair System ◽  
Combustion Engines ◽  
Independent Factor ◽  
Dependent Variables ◽  
Made In

The goal of this article is the fault analysis of combustion engines on the basis of the assessment of dependent variables: initial mileage, annual mileage and the annual number of orders made in the service and repair system compared with the independent factor, i.e. bus make. In the research four vehicle makes were tested: Jelcz M121, Mercedes-Benz Citaro, Solaris Urbino 12 and Autosan Sancity 12LF. The research encompassed the number of faults of a vehicle and its systems, the initial and annual mileage. It was conducted on the basis of 2015 data broken into particular months.

scholarly journals Assessment of thermodynamic cycle of internal combustion engine in terms of rightsizing

2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Internal Combustion ◽  
Research Problem ◽  
Combustion Engines ◽  
Operating Characteristics ◽  
Swept Volume

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.

FEATURES OF MEASURING THE CAMSHAFT OF INTERNAL COMBUSTION ENGINES

2021 ◽  
Vol 4 (30) ◽  
pp. 99-105
Author(s):  
A. V. Summanen ◽  
◽  
S. V. Ugolkov ◽  
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Technical Condition ◽  
Combustion Engines

This article discusses the issues of assessing the technical condition of the camshaft, internal combustion engine. The necessary parameters for assessing the technical condition of the engine camshaft have been determined. How and how to measure and calculate this or that parameter is presented in detail. Methods for calculating the parameters are presented. A scheme and method for measuring neck wear, determining the height of the cam, determining the beating of the central journal of the camshaft are proposed. The main defects of the camshafts are presented. The issues of the influence of these parameters on the operability of the camshaft and the internal combustion engine as a whole are considered.

Possibility of using gas lubricant in the cylinders of internal combustion engines of transport vehicles

2021 ◽  
pp. 13-20
Author(s):  
Keyword(s):  
Internal Combustion Engine ◽  
Bearing Capacity ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Engine Piston ◽  
Suspension Stiffness ◽  
Gas Layer

The prospects of using the gas-static suspension of the internal combustion engine piston in transport vehicles and power plants are considered. The diagram of the piston and the method for calculating the stiffness and bearing capacity of the gas layer surrounding the piston are presented, as well as the results of experiments that showed the relevance of this method. The possibility of gas and static centering of the engine piston is confirmed. Keywords: internal combustion engine, piston, gasstatic suspension, stiffness, bearing capacity, gas medium. [email protected]

Calculation of Acoustic Efficiency of Exhaust Silencers for Automotive Internal Combustion Engines

2021 ◽  
pp. 41-47
Author(s):  
Vladimir Tupov ◽  
O. Matasova
Keyword(s):  
Acoustic Waves ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Control Point ◽  
Plane Waves ◽  
Exhaust System ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Exhaust Noise ◽  
Insertion Losses

Insertion losses as the main characteristic that mathematically describes the acoustic efficiency of a noise silencer has been considered. This characteristic shows the reduction of noise generated by its source, in particular by the internal combustion engine’s exhaust system, at the control point as a silencer use result. Has been presented a mathematical description of the insertion losses, and have been considered parameters necessary for calculating this characteristic. Has been demonstrated the analytical dependence of impedance for the sound emission by the exhaust system’s end hole from the coefficient of acoustic waves reflection by this hole. The performed analysis of the widely used formulas for calculating the coefficient of sound reflection by the end hole has showed their insufficient accuracy for project designs performing. Have been proposed calculation dependences providing high accuracy for calculations of the reflection coefficient modulus, and the attached length of the channel end hole without a flange in the entire range of the existence of plane waves in it. It has been shown that the end correction of this hole at ka = 0 is 0.6127, and not 0.6133, as it was mistakenly believed until now in world acoustics. Has been proposed a method for calculation the exhaust noise source internal impedance. This method more accurately, in comparison with the already known ones, describes the acoustic processes in the internal combustion engine’s exhaust manifold, thanks to increases the accuracy of calculation the silencer acoustic efficiency, that allows develop the silencer at the early stages of the design of an automotive internal combustion engine.

A Novel Way of Manipulating and Optimizing CAM Profiles for Internal Combustion Engines

2007 ◽  
Author(s):  
Satheesh Makkapati ◽  
Kim Ku ◽  
Steve Poe
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Computationally Efficient ◽  
Trade Offs ◽  
Cam Profile ◽  
Computer Codes ◽  
Tool Optimization ◽  
Automated Tool

Generating an optimum cam profile for an internal combustion engine application is usually a very involved process. This is because of the challenge faced by the engine engineers to perform several trade-offs between fuel economy, performance, durability and emissions. Typically, the trade offs are worked out using several computer codes and with the involvement of a cross-functional team of engineers. Hence, there is a need to develop a tool that can encapsulate the various computer codes and can manipulate the cam profile with ease. With the existence of such an automated tool, optimization of the cam profile can be achieved with a specified trade-off between the several metrics identified above. This paper describes the development of such a tool, and discusses the ingredients that make it flexible and computationally efficient. Results from the use of this tool are documented in this paper as well.

Sign in / Sign up

Export Citation Format

Share Document