scholarly journals CFD Simulation of Knock Onset in a Heavy-Duty Spark Ignition Gas Engine

2019 ◽  
Vol 8 (4) ◽  
pp. 9585-9593
Keyword(s):  
Fluid Dynamics ◽  
Numerical Model ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Heavy Duty ◽  
Gas Engine ◽  
Optimization Study ◽  
Computational Fluid Dynamics Cfd

The paper describes a method for evaluating knocking onset with computational fluid dynamics (CFD) numerical model of the combustion process of spark ignited (SI) gas engine and methods for assessing the probability of knocking combustion based on this model. The probability of knocking combustion, which characterizes the boundary condition between normal combustion and knocking, is determined (8%). An optimization study of the influence of adjustment parameters on the probability of knocking based on a three-dimensional numerical model is carried out. The developed and tested technique allows one to monitor the tendency of the influence of various adjustment parameters on the probability of knocking in a SI gas engine.

scholarly journals Experimental Research and Computer Simulation of Knock Onset in a Heavy-Duty Si Gas Engine

2019 ◽  
Vol 8 (12) ◽  
pp. 730-736
Keyword(s):  
Boundary Condition ◽  
Numerical Model ◽  
Test Bench ◽  
Combustion Process ◽  
Three Dimensional ◽  
Engine Fuel ◽  
Heavy Duty ◽  
Gas Engine ◽  
Optimization Study ◽  
3D Numerical Model

The work describes the properties of natural gas as a engine fuel, as well as a method for evaluating knocking combustion at a test bench, a 3D numerical model of the combustion process of spark ignited (SI) gas engine and methods for assessing the probability of knocking combustion based on this model. The probability of knocking combustion, which characterizes the boundary condition between normal combustion and knocking, is determined (8%). An optimization study of the influence of adjustment parameters on the probability of knocking based on a three-dimensional numerical model is carried out. The developed and tested technique allows one to monitor the tendency of the influence of various adjustment parameters on the probability of knocking in a SI gas engine

Numerical Model of the Start-Up Process of a Honeycomb Regenerator

2012 ◽  
Vol 532-533 ◽  
pp. 436-440
Author(s):  
Chong Zhi Mao ◽  
Qian Jian Guo ◽  
Lei He
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Calculation ◽  
Numerical Model ◽  
Thermal Process ◽  
Three Dimensional ◽  
Outlet Temperature ◽  
Start Up ◽  
Computational Fluid Dynamics Cfd ◽  
Ceramic Honeycomb

Ceramic honeycomb is a key component of high temperature air combustion (HiTAC) system and the three-dimensional numerical model is established which is for investing unsteady thermal process in honeycomb regenerator. The start-up period of honeycomb was simulated by means of computational fluid dynamics (CFD) software; the outlet temperature were obtained. The work in this paper provides a theory basis and guide to the exploitation and appliance of HTAC system and the results of the numerical calculation can be used as the foundation of engineering design.

Study on Temperature Distribution of a Honeycomb Regenerator during Preheating Process

2012 ◽  
Vol 170-173 ◽  
pp. 2699-2702
Author(s):  
Zhen Min Cui
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Temperature ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Three Dimensional ◽  
Combustion Method ◽  
Outlet Temperature ◽  
High Temperature Air Combustion ◽  
Computational Fluid Dynamics Cfd

The HiTAC technology (High Temperature Air Combustion) is a reliable, industry proven combustion method. A three-dimensional numerical model is established which is for unsteady preheating process in honeycomb regenerator. The preheating period of honeycomb was simulated by means of computational fluid dynamics (CFD) software; the outlet temperature, temperature at lengthways of gas, and temperature at lengthways of honeycomb were obtained.

Off Set Strip Fins Thermo Hydraulic Performance Analysis Through CFD Simulation

2013 ◽  
Author(s):  
Guisselle Polo ◽  
Antonio Bula
Keyword(s):  
Fluid Dynamics ◽  
Cfd Simulation ◽  
Computational Simulation ◽  
Three Dimensional ◽  
Hydraulic Performance ◽  
Constant Flow ◽  
Uniform Temperature ◽  
Colburn Factor ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance

A computational simulation of the thermo hydraulic performance of a trapezoidal Off Set Strip Fin (OSF) is performed. The simulations are carried for Reynolds number ranging from 300 to 9000 considering three-dimensional conditions (3D). Calculations were developed assuming a constant flow. Colburn factor j, and the friction factor f, were calculated. Uniform temperature condition is assumed at the solid surface and at the inlet. The results have been compared with studies made by Kays and London, (1984), Manglik and Bergles (1990), and Muzychka and Yovanovich, (2001). According to the obtained results, it can be concluded that Computational Fluid Dynamics (CFD) is able to explore the behavior and performance of this kind of fin, showing that the hydraulic performance is well represented by correlations widely used in literature, while thermal performance seems to be under predicted.

Investigation of Multistage Combustion Inside a Heavy-Duty Natural-Gas Spark-Ignition Engine Using Three-Dimensional Computational Fluid Dynamics Simulations and the Wiebe-Function Combustion Model

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Gas ◽  
Burning Rate ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Heavy Duty ◽  
Piston Speed ◽  
Wiebe Function

Abstract The conversion of existing heavy-duty diesel engines to lean natural-gas (NG) spark ignition can be achieved by replacing the diesel injector with a spark plug and fumigating the NG into the intake manifold. While the original fast-burn diesel chamber will offset the lower NG flame speed, it will result in a two-stage combustion process (a stage inside and another outside the bowl). However, experimental data at more advanced spark timing, equivalence ratio of 0.8, and mean piston speed of 6.5 m/s suggested an additional combustion stage (i.e., three combustion stages). A three-dimensional (3D) computational fluid dynamics (CFD) simulation and a zero-dimensional triple Wiebe-function model were used to better understand the phenomena. While 78% fuel burned inside the bowl, burning rate reduced significantly when the flame approached the squish entrance and the bowl bottom. Moreover, the triple Wiebe-function indicated that the burn inside the squish was also divided into two separate combustion stages, due to the particularities of in-cylinder flow before and after top dead center. The first stage was fast and took place inside the compression stroke. The second took place in the expansion stroke and produced a short-lived increase in the burning rate, probably due to the increasing squish height during the expansion stroke and the increased combustion-induced turbulence, hence the third heat-release peak. Overall, these findings support the need for further investigations of combustion characteristics in such converted engines, to benefit their efficiency and emissions.

scholarly journals Streaming Birefringence - A Step Forward

2008 ◽  
Vol 13-14 ◽  
pp. 23-28 ◽  
Author(s):  
T. Spalton ◽  
Rachel A Tomlinson ◽  
A.E. Garrard ◽  
S.B.M. Beck
Keyword(s):  
Fluid Dynamics ◽  
Aqueous Solution ◽  
Flow Field ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Cfd Simulations ◽  
Full Field ◽  
Phase Stepping ◽  
Computational Fluid Dynamics Cfd

An investigation into three dimensional fluid flow has been conducted which combines the use of Computational Fluid Dynamics (CFD) simulations with the experimental phenomenon of Streaming Birefringence. A versatile flow channel was designed and built for use in conjunction with a circular polariscope. The experimental liquid used was an aqueous solution of a dye, commercially known as Milling Yellow NGS with the addition of Sodium Chloride. To extract the flow fields, six image phase stepping photoelasticity was used over backward and forward steps, and flows around a cylinder, and full-field fringe data were obtained. This method needs laminar flow regimes and the Reynolds number of the flow was around 10. To allow direct comparisons of the CFD solutions with the optical results, a macro (UDF) was written to interpret the flow field results from a (FLUENT6) CFD simulation. This integrated the shear stresses across the flow field and banded the results into fringes. A good correlation between the simulated fringes and the shearstrain rate was obtained from these observations.

Effect Investigation of the Circumferential Grooves on the Static Characteristics of Hydrodynamic Journal Bearing Using CFD Method

2014 ◽  
Vol 643 ◽  
pp. 316-321
Author(s):  
Qing Zheng Meng ◽  
Lin Cai ◽  
Miao He
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Cfd Simulation ◽  
Journal Bearing ◽  
Static Characteristics ◽  
Computational Fluid Dynamics Cfd ◽  
Hydrodynamic Journal Bearing ◽  
Good For ◽  
Cfd Method

The performance of a hydrodynamic journal bearing with different center circumferential grooves (CGs) is investigated using Computational fluid dynamics (CFD) simulation. The influences of the CG extended angel have been investigated based on the numerical model. The results show that the CG of millimeter range depth in load zone is not good for the bearing performance but it is opposite in unload zone.

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