scholarly journals Simulation tests of selected gas flow parameters through combustion engine valves

2020 ◽  
Vol 183 (4) ◽  
pp. 21-28
Author(s):  
Monika Andrych-Zalewska
Keyword(s):  
Gas Flow ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Cross Sectional ◽  
Ic Engine ◽  
Flow Parameters ◽  
Sectional Plane ◽  
Concise Representation ◽  
Engine Valves

The article presents the numerical analysis of a single-cylinder gasoline engine with indirect injection and spark ignition. The goal is to recognize and analyze gas flow through inlet and outlet valves and channels. These data were obtained from the simulation of a four-cycle engine cycle without combustion of the fuel-air mixture. The simulation was carried out in ANSYS, using a dedicated IC Engine module. After the simulation, the result was analyzed on the cross-sectional plane of both the valves and the combustion chamber. This method provided the necessary and concise representation of the flow characteristics. Five separate stages are presented - two describing the different displacement of the valve for each inlet and exhaust stroke and one representing the phenomenon of overlapping. The type of flow, its speed and tendency to create turbulence are described

Evaluation of the Effect of Gas Leakage on Operation of an Optical Engine

2010 ◽  
Author(s):  
E. Kapusuz ◽  
B. Ekici
Keyword(s):  
Gas Flow ◽  
Combustion Engine ◽  
Numerical Study ◽  
Mass Loss Rate ◽  
Ic Engine ◽  
Gas Leakage ◽  
Engine Model ◽  
Optical Engine ◽  
Laser Diagnostic ◽  
Flow Through

An experimental and numerical study is carried out to evaluate the significance of gas leakage for a non-lube optically accessible internal combustion engine and to obtain estimation for the gas flow out of the combustion chamber at each engine cycle and its effect on the in-cylinder component states during optical engine’s operation. Attention is paid to blow-by and circumferential flow through the gaps between the piston rings and the liner. Optical engines are typically operated without lubrication to avoid window fouling and generation of fluorescence by oil particles that interfere with laser diagnostic signals, in view of this circumstance significant blow-by is expected in optical engines due to lack of “wet-seal” on the cylinder walls which permits circumferential flow of gases through the piston ring pack region resulting in increased blow-by. Semi analytical model estimating the mass loss rate is incorporated into zero dimensional thermodynamic IC engine model which simulates in-cylinder processes. Predicted results are compared for leaking and non-leaking engine simulations.

The Simulation and Optimization on Flow Field in Intake Port of Engine Based on RE and CFD

2014 ◽  
Vol 1079-1080 ◽  
pp. 926-929
Author(s):  
Dan Han ◽  
Qian Wang ◽  
Bing Huan Li ◽  
Guo Jun Zhang ◽  
Shuo Wang
Keyword(s):  
Flow Field ◽  
Laser Scanning ◽  
Gas Flow ◽  
Gasoline Engine ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Intake Port ◽  
Three Dimensional Model ◽  
Simulation And Optimization

Intake port is an important part of the gasoline engine, its structure will influence the gas flow characteristics which directly affects the performance of the engine [1]. In this paper, three-dimensional CFD calculation and structural optimization were used to research the performance of gasoline engine. Firstly, the method of laser scanning and UG software were used to reverse modeling engine exhaust port and get the three-dimensional model. Secondly, after setting boundary conditions and turbulence models, the air flowing through the intake ports were simulated by FLUENT software respectively. Finally, based on numerical methods, the pressure field, velocity field were shown. The results of the simulation of flow field characteristics analysis show that the simulation and experimental results are in good agreement.

Modeling and Estimation of Unmeasured Variables in a Wastegate Operated Turbocharger

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Rasoul Salehi ◽  
Gholamreza Vossoughi ◽  
Aria Alasty
Keyword(s):  
Gas Flow ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Pressure Ratio ◽  
Mean Value ◽  
Compressible Fluids ◽  
Effective Pressure ◽  
Engine Modeling ◽  
Constant Area ◽  
Proper Operation

Estimation of relevant turbocharger variables is crucial for proper operation and monitoring of turbocharged (TC) engines, which are important in improving fuel economy of vehicles. This paper presents mean-value models developed for estimating gas flow over the turbine and the wastegate (WG), the wastegate position, and the compressor speed in a TC gasoline engine. The turbine is modeled by an isentropic nozzle with a constant area and an effective pressure ratio calculated from the turbine upstream and downstream pressures. Another physically sensible model is developed for estimating either the WG flow or position. Provided the WG position is available, the WG flow is estimated using the orifice model for compressible fluids. The WG position is predicted considering forces from the WG passing flow and actuator. Moreover, a model for estimating the compressor speed in low and medium compressor pressure ratios is proposed, using the compressor head and efficiency modified by the turbine effective pressure ratio. The estimates of the turbocharger variables match well with the experimentally measured data. The three proposed models are simple in structure, accurate enough to be utilized for engine modeling, and suitable to be validated and calibrated on an internal combustion engine in a test cell.

scholarly journals Analysis of impact of EGR valve construction on the exhaust gas flow parameters in the engine

2013 ◽  
Vol 154 (3) ◽  
pp. 79-85
Author(s):  
Agata LENC-BROL ◽  
Jarosław MAMALA
Keyword(s):  
Diesel Engine ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Simulation Studies ◽  
Valve Design ◽  
Flow Parameters ◽  
Recirculation System ◽  
Gas Recirculation

In this paper an analysis of the EGR valve design impact, in particular the outlet diameter, on the gasflow parameters in diesel engine (Z1505) exhaust gas recirculation system ofZetor tractor was made. For this purpose the experimental and simulation studies of gasflow through the valve were carried out. The simulations using Fluent were made. Also distribution of the pressure and velocity vectors in the area of the valve outflow was presented. Analysis of the phenomena occurring in the exhaust area of the EGR valve was made. Also influence of the outlet diameter on the flow characteristics of the EGR valve was determined.

The Influence of Exhaust Poppet Valve Gas Flow on Reciprocating Engine Noise

1975 ◽  
Vol 189 (1) ◽  
pp. 461-469 ◽  
Author(s):  
T. J. Williams ◽  
J. B. Cox
Keyword(s):  
Gas Flow ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Exhaust System ◽  
Gas Flows ◽  
Frequency Spectra ◽  
Reciprocating Engine ◽  
Flow Through ◽  
Field Noise ◽  
Good Agreement

The far field noise generated by cold air flowing through stationary and reciprocating exhaust poppet valves into a cylindrical duct or pipe has been investigated. A method of predicting the intensity and frequency spectrum of the noise generated in such circumstances in terms of the known or assumed geometry and flow characteristics of the valves is presented. Comparisons of the predicted frequency spectra with measured values show good agreement for steady gas flows through stationary valves and for unsteady flow through a simplified exhaust system of a motored single cylinder internal combustion engine.

Computational Analysis of Flow Dynamics in a Four-Stroke Internal Combustion Engine

2014 ◽  
Vol 1030-1032 ◽  
pp. 1163-1166
Author(s):  
Shian Gao ◽  
Peter Blunt ◽  
Robert Simpson
Keyword(s):  
Steady State ◽  
Pressure Wave ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Transient Pressure ◽  
Inlet Valve ◽  
Ic Engine ◽  
Wave Effects ◽  
Detailed Simulation ◽  
Inlet Manifold

This paper presents a predictive investigation using CFD techniques focusing on the tradeoff between steady-state airflow considerations and unsteady transient pressure wave tuning of a single cylinder IC engine. An axisymmetric CFD model has been developed to initially examine the steady-state flow characteristics generated by different inlet entry radii. This has then been further developed to incorporate the unsteady, transient pressure wave effects caused by the motion of inlet valve and piston. Detailed simulation results, which are validated against experimental data provided by Group Lotus plc, are reported here and quantitative conclusions are drawn for maximising airflow in future inlet manifold design.

scholarly journals Physical Simulation on Molten Steel Flow Characteristics of RH Vacuum Chamber with Arched Snorkels

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhi-Feng Ren ◽  
Zhi-Guo Luo ◽  
Fan-Xia Meng ◽  
Zong-Shu Zou ◽  
Yi-Hong Li ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Vacuum Chamber ◽  
Physical Simulation ◽  
Mixing Time ◽  
Flow Characteristics ◽  
Circulation Flow ◽  
Cross Sectional ◽  
Refining Efficiency ◽  
Circulation Flow Rate

The RH vacuum refining technology is a vitally powerful method of producing clean steel. The inner diameter of traditional circular snorkel is very difficult to be increased owing to the metallurgical refractory thickness around the snorkels and the limitation of the area under the vacuum chamber, limiting the increase in refining efficiency. In order to improve the refining efficiency of the RH reactor, a new designed RH degasser with an optimized arched snorkel is established. This design replaces the traditional two circular snorkels structure with the two arched snorkels and greatly enhances the cross-sectional area of snorkel. In this study, the flow characteristics of this new type RH were studied and analyzed by establishing a 1 : 5.5 physical model of RH with arched snorkels. Results show that the circulation flow rate of RH with arched snorkels can increase by 100% ∼ 180% and the mixing time approximately decreases by 35% compared with RH with circular snorkels under actual production conditions. The circulation flow rate of RH with arched snorkels continues to increase obviously when gas flow rate exceeds the saturated value of RH with circular snorkels. The RH with arched snorkels can increase the refining efficiency significantly and has important application prospect.

scholarly journals One-Dimensional Numerical Analysis of Cross-Sectional Area Variation Effects on Flow through the Gas Turbine Diffuser

2019 ◽  
Author(s):  
Nima Zamani Meymian ◽  
Reza Khodadadi
Keyword(s):  
Mach Number ◽  
Boundary Conditions ◽  
Gas Turbine ◽  
Cross Section ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Time Step ◽  
Cross Sectional ◽  
One Dimensional ◽  
Length Changes

In the paper, a one-dimensional compressible flow of gas inside the gas turbine’s diffuser has been simulated. The modeling has been performed to the aim of obtaining boundary conditions of outlet gas from diffuser and inlet gas to the combustion chamber. Depending on working flow regimes of fluid including subsonic, transonic, and supersonic flows, changes of diffuser cross-section have different effects on gas flow characteristics. For these effects to be correctly imposed, Mach number of the gas flow in each time-step affected by changes of cross-section would be determined, depending on the local Mach number in the same time-step. Obtaining distribution of Mach number along diffuser length, changes in other main characteristics of flow such as pressure, temperature, speed, and density for all of the points along diffuser length would be obtained. In order to verify the validity of the numerical algorithm used, the gas flow would be solved in a divergent nozzle and compared to other numerical methods. In the end, using gas turbine diffuser’s geometrical information, compressible gas flow inside it would be studied using the actual boundary conditions for a 25 MW gas turbine.

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