Heterogeneous combustion in a diesel engine is noisier, uncontrolled and more polluting. This can be achieved with a strategic approach of a reactivity-controlled compression ignition (RCCI) mode engine that operates with low and high reactive fuel combinations. In the present work, a diesel engine is operated in RCCI mode with gaseous fuels viz. CNG as a primary fuel and a blend of diesel and Karanja biodiesel (BD20) as pilot fuel. This research aims to determine the operating limits of CNG fuel for less noisy combustion and clean exhaust. Further, relative air-fuel ratio (λ), cycle to cycle variations, combustion noise and emissions were studied for full load operation. The CRDI engine is optimized for diesel operation with a split injection strategy. The knock limits for CNG as the primary fuel are obtained. The combustion noise increases at a higher energy share by CNG. Also, higher values of HC and CO emissions are observed. This may be due to higher energy share values, flame speed and octane number of CNG fuel. Further, NOx emissions and smoke are decreased. The CNG induction of 10 ms with 90% ES can be noted as a knock limit for 3.5 kW power. The highest BTHE of 24.2% and least BSFC 0.3 kg/kWhr reported by 60%ES of LRF is better than diesel and KBD20 fuel. An optimum 60% energy share of CNG is observed for clean combustion and emissions strategy using the RCCI mode of a modified diesel engine.

Clean combustion and emissions strategy using reactivity controlled compression ignition (RCCI) mode engine powered with CNG-Karanja biodiesel

Collective effect of ternary nano fuel blends on the diesel engine performance and emissions characteristics

In this study, a thermodynamic cycle simulation of a conventional four-stroke SI engine has been carried out to predict the engine performance and emissions. The first law of thermodynamics has been applied to determine in-cylinder temperature and pressure as a function of crank angle. The Newton-Raphson method was used for the numerical solution of the equations. The non-differential form of equations resulted in the simplicity and ease of the solution to predict the engine performance. Two-zone model for the combustion process simulation has been used and the mass burning rate was predicted by simulating spherical propagation of the flame front. Also, temperature dependence of specific heat capacity has been considered. The performance characteristics including power, indicated specific fuel consumption, and emissions concentration of SI engine using gasoline and CNG fuels have been determined by the model. The results of the present work have been evaluated using corresponding available experimental data of an existing SI engine running on both gasoline and CNG. It has been found that the simulated results show reasonable agreement with the experimental data. Finally, parametric studies have been carried out to evaluate the effects of equivalence ratio, compression ratio and spark timing on the engine performance characteristics in order to show the capability of the model to predict of engine operation.

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Thermodynamic model for prediction of performance and emission characteristics of SI engine fuelled by gasoline and natural gas with experimental verification

Various nanofluids (NFs) have been prepared using nanoparticles (NPs) for dual fuel engine application in this present work. In the initial segment of the work, the NF’s are prepared using aluminum oxide nanoparticles (Al2O3). Further, nanoparticles were blended with diary scum oil methyl ester (DiSOME) in the mass fraction of 10–30 ppm in steps of 10, with the assistance of a mechanically operated conventional homogenizer and an ultrasonicator. In the next segment of the work, Al2O3 NP’s effect on the characteristics of ignition and engine outgas levels of a single cylinder four strokes direct injection diesel engine functioning on dual fuel mode using DiSOME and producer gas (PG) has been investigated. Engine testing showed that experiments with Al2O3 based NF and PG operation resulted in 11.5% amplified brake thermal efficiency, 23.2% reduction in smoke, 18.2–21.4% reduction in hydrocarbon (HC) and carbon monoxide (CO) emissions, while more significant nitric oxide (NOx) levels by 32.6% were achieved than the same fuel combination excluded NP’s at 80% load.

Utilization of biodiesel/Al2O3 nanoparticles for combustion behavior enhancement of a diesel engine operated on dual fuel mode

Performance indicators for the optimal BTE of biodiesels with additives through engine testing by the Taguchi approach

Milk scum is a waste obtained in milk dairies, which can be used as a raw material for producing biodiesel by a transesterification process In this research study, the biodiesel obtained from milk scum was blended with diesel to make binary blends (B20D80, B60D40 and B100) These binary blends were further blended with ethanol in different percentages to make ternary blends (B20E05D75, B20E10D70, B20E15D65) Physical and chemical properties of binary and ternary blends were investigated and compared Degradation of physical properties of the prepared biodiesels with respect to time was studied, which is the salient part of the work Engine performance test was conducted in a single-cylinder diesel engine Performance of the engine for different blends (both binary and ternary) was recorded and compared Addition of 5% ethanol showed a decrease in fuel consumption, whereas higher content (15%) of ethanol showed rapid increase in fuel consumption as compared to that of binary blends Ternary blend containing 5% ethanol showed higher brake thermal efficiency (BTE) compared to D100 (diesel only), while ternary blends containing 10 and 15% ethanol gave lower BTE compared to 5% ethanol and D100 The blend B20E05D75 is considered as better alternative fuel upon comparing mass fuel consumption, air fuel ratio and brake thermal efficiency with all rest of blends tested in this study

Combined Effect of Synthesized Waste Milk Scum Oil Methyl Ester and Ethanol Fuel Blend on the Diesel Engine Characteristics

The fuel heat release rate which virtually controls the combustion process is dependent on the ‘Mass-Fraction-Burnt (MFB)’. In the present research work, a ‘logistic model with conditional variability in MFB’, has been developed for precise simulation of combustion in SI engines as the model has built in routines to take into account such factors as location of spark plug, single/dual spark plugs, intake generated swirl, combustion chamber geometry (associated with Bore/Stroke ratio), etc. A major contribution of this paper is that new and improved models for the ‘overall combustion duration’, and ‘ignition delay/flame development angle’, taking into account primarily the influence of compression ratio on the overall combustion process in SI engine have been developed. Taylor’s original equation for estimating the overall combustion duration has been modified by including a logistic equation for the error term and incorporating it in the original equation. Ignition delay as proposed by Keck et al has been modified by incorporating a polynomial of 3rd order into the original equation. The empirical correlations that have been proposed in this paper may serve to be the starting point for simulation of ‘photodetonation concept’ to simulate HCCI combustion which is presently the hot research work in the area of pre-mixed combustion.

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Progressive combustion in SI-Engines—Experimental investigation on influence of combustion related parameters

Investigation of the Influence of Compression Ratio, Intake Air Temperature and Swirl in Intake passage on Random Cyclic Pressure Variations in Spark-Ignition Engines

Progressive Combustion in SI-Engines-Improved Empirical Models for Simulating and Optimizing Engine Performance

Cyclone separators are normally used for dust collection in rice mills from long time. However their dust collection efficiency is lower and is influenced by factors like geometry, exit pipe dimensions and length, humidity, temperature at dust generation place. The design of cyclone has been slightly altered, and the new design has proven to be successful in collecting the dust particles of size up to 10 microns, the major modification was to change the height of exit pipe of the cyclone chamber to have optimum dust collection. The cyclone is coupled with a tri chambered filter unit with three geo text materials filters of different mesh size to capture the dust less than 10 micron. Keywords-Cyclone,Rice Mill,Geo Text Materials.

R. Harish Kumar

Papers

Combined Effect of Synthesized Waste Milk Scum Oil Methyl Ester and Ethanol Fuel Blend on the Diesel Engine Characteristics

Progressive combustion in SI-Engines—Experimental investigation on influence of combustion related parameters

Investigation of the Influence of Compression Ratio, Intake Air Temperature and Swirl in Intake passage on Random Cyclic Pressure Variations in Spark-Ignition Engines

Progressive Combustion in SI-Engines-Improved Empirical Models for Simulating and Optimizing Engine Performance

Studies on Design of Cyclone Separator with Tri-Chambered Filter Unit for Dust Removal in Rice Mills