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1 – 10 of 43Ganesh Rupchand Gawale and Naga Srinivasulu G.
Homogeneous charge compression ignition (HCCI) engine is an advanced combustion method to use alternate fuel with higher fuel economy and, reduce NOX and soot emissions. This…
Abstract
Purpose
Homogeneous charge compression ignition (HCCI) engine is an advanced combustion method to use alternate fuel with higher fuel economy and, reduce NOX and soot emissions. This paper aims to investigate the influence of ethanol fraction (ethanol plus gasoline) on dual fuel HCCI engine performance.
Design/methodology/approach
In this study, the existing CI engine is modified into dual fuel HCCI engine by attaching the carburetor to the inlet manifold for the supply of ethanol blend (E40/E60/E80/E100). The mixture of ethanol blend and the air is ignited by diesel through a fuel injector into the combustion chamber at the end of the compression stroke. The experiments are conducted for high load conditions on the engine i.e. 2.8 kW and 3.5 kW maximum output power for 1,500 constant rpm.
Findings
It is noticed from the experimental results that, with an increase of ethanol in the blends, ignition delay (ID) increases and the start of combustion is retarded. It is noticed that E100 shows the highest ID and low in-cylinder pressure; however, E40 shows the lowest ID compared to higher fractions of ethanol blends. An increase in ethanol proportion reduces NOX and smoke opacity but, HC and CO emissions increase compared to pure diesel mode engine. E100 plus diesel dual-fuel HCCI engine shows the highest brake thermal efficiency compared to remaining ethanol blends and baseline diesel engine.
Originality/value
This experimental study concluded that E100 plus diesel and E80 plus diesel gave optimum dual fuel HCCI engine performance for 2.8 kW and 3.5 kW rated power, respectively.
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More stringent emission standards are being promulgated all over the world for regulating and decreasing the levels of emission more so caused from on-road vehicles and engines…
Abstract
Purpose
More stringent emission standards are being promulgated all over the world for regulating and decreasing the levels of emission more so caused from on-road vehicles and engines and for improving the air quality problems.
Design/methodology/approach
In this study, an attempt has been made to experimentally analyze the performance and emission characteristics of the premixed charge compression ignition (PCCI) mode assisted by a pilot injector.
Findings
The results indicate that brake thermal efficiency marginally decreases, and specific fuel consumption increases in all PCCI modes, and HC, CO emissions are higher in the case PCCI modes and oxides of nitrogen and soot levels are considerably reduced in the case of diesel PCCI-biodiesel and petrol PCCI-biodiesel modes.
Research limitations/implications
As obtaining very lean homogenous mixture is hard, it becomes difficult to sustain PCCI mode over the operating range of varying speeds and loads to effectively control the PCCI combustion over the operating range.
Social implications
Being a responsible human being, we all have the responsibility in keeping this world cleaner, free from all sort of pollution. In this regard, the concept of waste recycling and energy recovery plays a vital role in the development of any economy. This has led to resource conservation and pollution reduction.
Originality/value
The present work Jatropha oil methyl ester (JOME) was chosen as fuels for PCCI mode. Investigations were carried out with blends of JOME with diesel in PCCI combustion mode to evaluate the performance, combustion and emission characteristics of these fuels.
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Vahid Labbaf Khaniki and Nasser Seraj Mehdizadeh
The aim of this paper is to find the optimal values of the reaction rates coefficients for the combustion of a methane/air mixture for a given reduced reaction mechanism which has…
Abstract
Purpose
The aim of this paper is to find the optimal values of the reaction rates coefficients for the combustion of a methane/air mixture for a given reduced reaction mechanism which has a high appropriateness with full reaction mechanism.
Design/methodology/approach
A multi‐objective genetic algorithm (GA) was used to determine new reaction rate parameters (A's, β's, and Ea's in the non‐Arrhenius expressions). The employed multi‐objective structure of the GA allows for the incorporation of perfectly stirred reactor (PSR), laminar premixed flames, opposed flow diffusion flames, and homogeneous charge compression ignition (HCCI) engine data in the inversion process, thus enabling a greater confidence in the predictive capabilities of the reaction mechanisms obtained.
Findings
The results of this study demonstrate that the GA inversion process promises the ability to assess combustion behaviour for methane, where the reaction rate coefficients are not known. Moreover it is shown that GA can consider a confident method to be applied, straightforwardly, to the combustion chambers, in which complex reactions are occurred.
Originality/value
In this paper, GA is used in more complicated combustion models with fewer assumptions. Another consequence of this study is less CPU time in converging to final solutions.
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Rui Liu, Haocheng Ji and Minxiang Wei
The purpose of this paper is to investigate power performance, economy and hydrocarbons (HC)/carbon monoxide (CO) emissions of diesel fuel on a two-stoke direct injection (DI…
Abstract
Purpose
The purpose of this paper is to investigate power performance, economy and hydrocarbons (HC)/carbon monoxide (CO) emissions of diesel fuel on a two-stoke direct injection (DI) spark ignition (SI) engine.
Design/methodology/approach
Experimental study was carried out on a two-stroke SI diesel-fuelled engine with air-assisted direct injection, whose power performance and HC/CO emissions characteristics under low-load conditions were analysed according to the effects of ignition energy, ignition advance angle (IAA), injection timing angle and excess-air-ratio.
Findings
The results indicate that, for the throttle position of 10%, a large IAA with adequate ignition energy effectively increases the power and decrease the HC emission. The optimal injection timing angle for power and fuel consumption is 60° crank angle (CA) before top dead centre (BTDC). Lean mixture improves the power performance with the HC/CO emissions greatly reduced. At the throttle position of 20%, the optimal IAA is 30°CA BTDC. The adequate ignition energy slightly improves the power output and greatly decreases HC/CO emissions. Advancing the injection timing improves the power and fuel consumption but should not exceed the exhaust port closing timing in case of scavenging losses. Burning stoichiometric mixture achieves maximum power, whereas burning lean mixture obviously reduces the fuel consumption and the HC/CO emissions.
Practical implications
Gasoline has a low flash point, a high-saturated vapour pressure and relatively high volatility, and it is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. The authors adopt a low volatility diesel fuel for all vehicles and equipment to minimise the number of different devices using various fuels and improve the potential military application safety.
Originality/value
Under low-load conditions, the two stroke port-injected SI engine performance of burning heavy fuels including diesel or kerosene was shown to be worse than those of gasoline. The authors have tried to use the DI method to improve the performance of the diesel-fuelled engine in starting and low-load conditions.
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Rui Liu, Xiaoping Su, Xiaodong Miao, Guang Yang, Xuefei Dong, Yongsheng Liang and Taiqi Huang
The purpose of this paper is to compare the combustion characteristics, including the combustion pressure, heat release rate (HRR), coefficient of variation (COV) of indicated…
Abstract
Purpose
The purpose of this paper is to compare the combustion characteristics, including the combustion pressure, heat release rate (HRR), coefficient of variation (COV) of indicated mean effective pressure (IMEP), flame development period and combustion duration, of aviation kerosene fuel, namely, rocket propellant 3 (RP-3), and gasoline on a two-stoke spark ignition engine.
Design/methodology/approach
This paper is an experimental investigation using a bench test to reflect the combustion performance of two-stroke spark ignition unmanned aerial vehicle (UAV) engine on gasoline and RP-3 fuel.
Findings
Under low load conditions, the combustion performance and HRR of burning RP-3 fuel were shown to be worse than those of gasoline. Under high load conditions, the average IMEP and the COV of IMEP of burning RP-3 fuel were close to those of gasoline. The difference in the flame development period between gasoline and RP-3 fuel was similar.
Practical implications
Gasoline fuel has a low flash point, high-saturated vapour pressure and relatively high volatility and is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. Adopting a low volatility single RP-3 fuel of covering all vehicles and equipment to minimize the number of different devices with the use of a various fuels and improve the application safeties.
Originality/value
Most two-stroke spark ignition UAV engines continue to combust gasoline. A kerosene-based fuel operation can be applied to achieve a single-fuel policy.
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Kannan Chidambaram and Vijayakumar Thulasi
The development of a theoretical model for predicting the combustion, performance and emission characteristics of a cylinder head porous medium engine becomes necessary due to…
Abstract
Purpose
The development of a theoretical model for predicting the combustion, performance and emission characteristics of a cylinder head porous medium engine becomes necessary due to imposed requirements from the viewpoint of power, efficiency and toxic gases in the exhaust. The cylinder head porous medium engine was found to have superior combustion, performance and emission characteristics when compared to a conventional diesel engine. The paper aims to discuss these issues.
Design/methodology/approach
Due to heterogeneous and transient operation of diesel engine under conventional and porous medium mode, the combustion process becomes complex, and achieving a pure analytical solution to the problem was difficult. Although, closer accuracy of correlation between the computer models and the experimental results is improbable, the computer model will give an opportunity to quantify the combustion and heat transfer processes and thus the performance and emission characteristics of an engine.
Findings
In this research work, a theoretical model was developed to predict the combustion, performance and emission characteristics of a cylinder head porous medium engine through two-zone combustion modeling technique, and the results were validated through experimentation.
Originality/value
The two-zone model developed by using programming language C for the purpose of predicting combustion, performance and emission characteristics of a porous medium engine is the first of its kind.
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J. Beauquel, S. Ibrahim and R. Chen
After validation of the numerical model against published laser doppler anemometry (LDA) experimental data (Pitcher et al., 2003), numerical calculations have been carried out to…
Abstract
After validation of the numerical model against published laser doppler anemometry (LDA) experimental data (Pitcher et al., 2003), numerical calculations have been carried out to investigate the in-cylinder transient flow structure of a controlled auto-ignition (CAI) engine running at speeds of 1,500 rpm and 2,000 rpm. The geometry configuration of the engine is imported into the computational fluid dynamics (CFD) code used in this study. The simulations take into account the movement of the inlet, exhaust valves and the piston. To simulate an engine in controlled auto-ignition (CAI) mode, the same valve timing that allows 36% gas residuals was applied to the model. The evolution of the flow pattern inside the cylinder at the symmetrical cross section is described. Also, the turbulence intensity (TI), the turbulent kinetic energy (TKE) and turbulent dissipation rate (TDR) are described for a better understanding of the effect of engine speed on the turbulences generated. The effects of engine speed on fresh charge velocity are also revealed.
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J. Beauquel, S. Ibrahim and R. Chen
Numerical calculations have been carried out to investigate the in-cylinder transient flow structure of a controlled auto-ignition (CAI) engine running at speeds of 1500 rpm and…
Abstract
Numerical calculations have been carried out to investigate the in-cylinder transient flow structure of a controlled auto-ignition (CAI) engine running at speeds of 1500 rpm and 2000 rpm. The calculated turbulent flow structure and velocities are validated against published laser doppler anemometry (LDA) experimental data (Pitcher et al., 2003). The experimental data was reprocessed to represent the time dependent mean velocities for all measured points. The actual geometry configuration of the engine is imported into the computational fluid dynamics (CFD) code used in this study. The simulations take into account the movement of the inlet, exhaust valves and the piston. The CFD simulations replicate the experimental work where only air was inserted into a driven optical engine. Also, to simulate an engine in controlled auto-ignition (CAI) mode, the same valve timing that allows 36% internal exhaust gas recirculation (IEGR) was applied for the air intake. The calculated results found to agree well with the LDA measurements with an overall agreement of 75.06% at 1500 rpm and 73.42% at 2000 rpm.
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Ganji Prabhakar Rao, Vipin Dhyani, Deepak Kumar, V.R.K. Raju and S. Srinivasa Rao
This paper aims to present the effects of varying different operating parameters such as Start of Injection (9 to 21 deg bTDC), compression ratio (16 to 12.5), fuel injection…
Abstract
Purpose
This paper aims to present the effects of varying different operating parameters such as Start of Injection (9 to 21 deg bTDC), compression ratio (16 to 12.5), fuel injection pressure (400 to 1,400 bar) and exhaust gas recirculation (0 to 25 per cent) on the performance and emissions of the engine for constant engine speed of 1,600 rpm.
Design/methodology/approach
Simulation results were validated with experimental data available in the literature for baseline configuration. The effect of each parameter on the performance characteristics such as pressure and temperature, emission characteristics such as NOx and soot are presented and discussed. Optimization has been carried out based on the regression equations developed from the simulation results to obtain the optimum set of the parameters to achieve the desired performance and emissions. Numerical simulations have been performed for the optimized set and compared with the reference engine.
Findings
Results of optimization showed that there was a simultaneous reduction in NOx and soot while maintaining the same level of performance as that of the baseline case.
Originality/value
Based on the present work, it can be said that lesser emissions are achieved in terms of NOx and soot while maintaining the same performance in terms of peak pressure.
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S.V. Khandal, T.M. Yunus Khan, Sarfaraz Kamangar, Maughal Ahmed Ali Baig and Salman Ahmed N J
The different performance tests were conducted on diesel engine compression ignition (CI) mode and CRDi engine.
Abstract
Purpose
The different performance tests were conducted on diesel engine compression ignition (CI) mode and CRDi engine.
Design/methodology/approach
The CI engine was suitably modified to CRDi engine with Toroidal re-entrant combustion chamber (TRCC) and was run in dual-fuel (DF) mode. Hydrogen (H2) was supplied at different flow rates during the suction stroke, and 0.22 Kg/h of hydrogen fuel flow rate (HFFR) was found to be optimum. Diesel and biodiesel were used as pilot fuels. The CRDi engine with DF mode was run at various injection pressures, and 900 bar was found to be optimum injection pressure (IP) with 10o before top dead center (bTDC) as fuel injection timing (IT).
Findings
These operating engine conditions increased formation of oxides of nitrogen (NOx), which were reduced by exhaust gas recycle (EGR). With EGR of 15%, CRDi engine resulted in 12.6% lower brake thermal efficiency (BTE), 5.5% lower hydrocarbon (HC), 7.7% lower carbon monoxide (CO), 26% lower NOx at 80% load as compared to the unmodified diesel engine (CI mode).
Originality/value
The current research is an effort to study and evaluate the performance of CRDi engine in DF mode with diesel-H2 and BCPO-H2 fuel combinations with TRCC.
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