CFD modelling of the effect of guide vane swirl and tumble device to generate better in-cylinder air flow in a CI engine fuelled by biodiesel

2013 ◽  
Vol 84 ◽  
pp. 262-269 ◽  
Author(s):  
S. Bari ◽  
Idris Saad
Keyword(s):  
Air Flow ◽  
2018 ◽  
Vol 225 ◽  
pp. 02003
Author(s):  
Elaine Why ◽  
Firas Alnaimi ◽  
Hasril Hasini ◽  
Mohammad Nasif

Complete combustion of coal fuel in thermal power plant is often achieved, by ensuring output of fine coal particle (< 75μm) is as high as possible. This is due to the fact that same mass of coal particle in smaller sizes, has higher surface exposed to combustion. Hence, the objective of the study is to determine the effect of air flow rate and coal particle flow rate on coal fineness output. Computational fluid dynamics (CFD) modelling and validation with experimental coal fineness test in real plant are made. The optimum range of air flow rate and coal particle flow rate in pulverizer are selected, by considering relevant air/fuel ratio of 1.5 to 2.0 and turbulence intensity.


Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 439 ◽  
Author(s):  
Mohd Fadzli Hamid ◽  
Mohamad Yusof Idroas ◽  
Shukriwani Sa’ad ◽  
Teoh Yew Heng ◽  
Sharzali Che Mat ◽  
...  

Generally, the compression ignition (CI) engine that runs with emulsified biofuel (EB) or higher viscosity fuel experiences inferior performance and a higher emission compared to petro diesel engines. The modification is necessary to standard engine level in order to realize its application. This paper proposes a guide vane design (GVD), which needs to be installed in the intake manifold, is incorporated with shallow depth re-entrance combustion chamber (SCC) pistons. This will organize and develop proper in-cylinder airflow to promote better diffusion, evaporation and combustion processes. The model of GVD and SCC piston was designed using SolidWorks 2017; while ANSYS Fluent version 15 was utilized to run a 3D analysis of the cold flow IC engine. In this research, seven designs of GVD with the number of vanes varied from two to eight vanes (V2–V8) are used. The four-vane model (V4) has shown an excellent turbulent flow as well as swirl, tumble and cross tumble ratios in the fuel-injected region compared to other designs. This is indispensable to break up heavier fuel molecules of EB to mix with the air that will eventually improve engine performance.


Author(s):  
Arash Farahani ◽  
Peter Childs

Strip seals are commonly used to prevent or limit leakage flows between nozzle guide vanes (NGV) and other gas turbine engine components that are assembled from individual segments. Leakage flow across, for example, a nozzle guide vane platform, leads to increased demands on the gas turbine engine internal flow system and a rise in specific fuel consumption (SFC). Careful attention to the flow characteristics of strip seals is therefore necessary. The very tight tolerances associated with strip seals provides a particular challenge to their characterisation. This paper reports the validation of CFD modelling for the case of a strip seal under very carefully controlled conditions. In addition, experimental comparison of three types of strip seal design, straight, arcuate, and cloth, is presented. These seals are typical of those used by competing manufacturers of gas turbine engines. The results show that the straight seal provides the best flow sealing performance for the controlled configuration tested, although each design has its specific merits for a particular application.


Author(s):  
Idris Saad ◽  
Saiful Bari

The purpose of this study was to investigate the effect guide vane swirl and tumble device (GVSTD) on the in-cylinder airflow particularly to generate turbulent kinetic energy (TKE) and velocity inside the combustion chamber and around fuel injected region. High velocity and TKE would accelerate the evaporation, diffusion and mixing processes of CI engines, particularly when alternative fuels of higher viscosity and density (known as HVF — higher viscous fuel) are used. A verified simulation base model was prepared by the SolidWorks software and analysed using ANSYS software to study the reference data of the resulting in-cylinder airflow characteristics. Then GVSTD models were developed and imposed on the intake runner of the base model. The parametric optimization technique was used to find the optimum number of vanes for the GVSTD model. This was done by preparing 10 GVSTD models with the vane number varied from 3 to 12. The models were then tested on the base model individually. Generally, GVSTD improve in-cylinder TKE and velocity. Additionally, this research found that GVSTD with 3 vanes resulted in an improved TKE and velocity of about 6.3% and 10.4% respectively when compared to the base model. Therefore, it may be said that the use of GVSTD can increase the chances to improve the performance of a CI engine and reduce the emission when run on HVF.


2013 ◽  
Vol 393 ◽  
pp. 293-298 ◽  
Author(s):  
Idris Saad ◽  
Saiful Bari

Environmental issues and the depletion of worldwide crude oil sources have developed the requirement for an alternative fuel to power internal combustion engines. Vegetable oil, waste cooking oil and biodiesel are all renewable, environmentally sustainable and compatible with current Compression Ignition (CI) engines with little to no engine modification necessary. These fuels however have a higher viscosity than conventional petro-diesel and may be referred to as Higher Viscous Fuels (HVF). HVF have reduced in-cylinder combustion efficiency when compared with petro-diesel which reduces the engine performance in terms of output power, torque and fuel efficiency. A possible solution to the reduced efficiency is through the use of a Guide Vane Swirl and Tumble Device (GVSTD). This device when installed in front of the air intake manifold may produce improved air flow characteristics. This improves the efficiency of the evaporation processes and air-fuel mixing and therefore improves overall combustion efficiency. The effect of GVSTDs on in-cylinder air flow was studied using 3D Internal Combustion (IC) engine simulation under motored engine conditions. This was done using ANSYS-CFX. The base model engine was adapted from the Hino W04D model CI engine. The model throughout all simulations was run at a constant speed of 1500 rpm. There are four parameters to consider for GVSTD models; vane length, vane height, vane angle and the number of vanes. For the purpose of this study, the vane height, vane angle and the number of vanes were maintained as constants leaving the vane length as the variable parameter. 11 GVSTD models were simulated each varying from 1.5 to 4.5 times the radius of the intake runner (R) in 0.3R increments. To analyze the air-flow characteristics, the maximum in-cylinder pressure, Turbulence Kinetic Energy (TKE) and velocity were measured. It was found that for the constant values for vane height, vane angle and the number of vanes of 0.2R, 35° twist angle and 4 perpendicularly-arranged respectively, the in-cylinder pressure, TKE and velocity were optimum for the vane lengths of 3.6 to 3.9 times R.


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