Toroidal Combustion Chamber Research Articles

Emission analysis of combustion of cashew nutshell biodiesel in a toroidal combustion chamber: an experimental study

Emission analysis of combustion of cashew nutshell biodiesel in a toroidal combustion chamber: an experimental study

Synergistic approaches to NOx reduction: Fuel innovations and engine modifications in biomass waste-fueled CI engines

Achieving low nitric oxide emissions in biomass fuel combustion remains a challenge. This study aims at enhancement of NOx reduction by employing a sequence of strategies to arrive at the optimal combination of techniques. This work explores the role of nano particle emulsion, change in profile of combustion chamber geometry, exhaust gas recirculation rates and contribution of selective catalytic reduction (SCR) in the combustion and emission phenomena of CI engine. Cerium oxide and zinc oxide nanoparticles are added in emulsion form at 50 ppm and 100 ppm dosage to grapeseed oil biodiesel. Furthermore, combustion chamber geometry is modified to shallow depth and toroidal shape and tested with ZnO 100 nano blend of grapeseed oil biodiesel (GSBD). EGR at 5 %, 10 %, 15 % and 20 % rates are included in the toroidal shape after concluding that profile as the best performing geometry. A customized model of SCR is implemented to the above combination of ZnO fuel blend, toroidal combustion chamber geometry and 5 % EGR to further reduce NOx emission. SCR device is fabricated with suitable flow and injection parameters with dual type mixers to enhance its NOx conversion efficiency. Overall, this research work gives useful insights for development of NOx reduction strategies in biomass fuel combustion in CI engines. A comprehensive reduction of NOx from 9.3 g/kWh to 2.05 g/kWh is noticed at the end of cumulative set of experiments.

Influence of hydrogen-assisted combustion in compression ignition engines fueled with fuel blends of pine oil and waste cooking oil biodiesel using toroidal combustion chamber

In this research study, fuel blends of pine oil and waste cooking oil biodiesel (P/WCO) were examined for combustion analysis, engine performance, and emission characteristics tests. Improved combustion and engine performance were achieved using a toroidal re-entrant combustion chamber (TCC) and hydrogen supply as a dual fuel. The combustion behavior of fuel blends and hydrogen fuel was examined by varying the engine load at a constant speed. The results revealed that significant reduction in the specific fuel consumption for rich pine oil. Thus, a slightly lesser energy share from the fuel blends and a higher energy share from the hydrogen fuel was required for the engine to maintain the same brake power. Lower viscosity, higher flash point, and presence of oxygen in the pine oil enhance the combustion rate and brake thermal efficiency. Furthermore, hydrogen induction in the engine improves the flame velocity. A lesser crevice volume in the TCC can trap the unburnt fuel which can further increase the combustion efficiency. Thus, rich pine oil with the support of hydrogen induction in TCC causes advanced ignition, improved combustion, and more heat release during the combustion. The investigation results revealed that hydrogen induction increases the heat release rate and peak pressure by 7.4% and 2.67%, respectively. Similarly, the maximum of 24.55% increase in BTE and 18.22% reduction in BSFC was observed due to a constant 10 lpm hydrogen induction. Furthermore, hydrogen fuel significantly reduces the emissions such as CO, HC, CO2, and smoke. However, more NOx was generated due to more heat release rate during combustion. Thus, pine oil and waste cooking oil biodiesel blends with the support of hydrogen induction in TCC improve the engine performance and mitigate the toxic pollutants and can be a suitable alternative to diesel fuel.

Refining Combustion Dynamics: Dissolved Hydrogen in Diesel Fuel within Turbulent-Flow Environments

This article presents the possibility of improving combustion using the effect of releasing hydrogen from a solution with nucleation of gas bubbles. This concept consists in dissolving hydrogen in diesel fuel until the equilibrium state of the solution is reached. At a later stage, the phenomenon is reversed, and this gas is released from the solution during its injection into the combustion chamber with a strong swirl. A characteristic feature of the solution is that when lowering the pressure (opening the atomizers), there is a decrease in the equilibrium thermodynamic potential, which results in the excess, dissolved hydrogen being released spontaneously, and this process is of a volumetric nature. This article is a continuation of the work carried out at Poznan University of Technology on the development of this concept. This article presents the results of tests for the impact of hydrogen dissolved in diesel fuel on the combustion process within a turbulent-flow environment. The tests were conducted in the combustion chamber of an engine equipped with a toroidal combustion chamber and direct injection. During the tests, the following factors were measured: the main indicators of motor operation, emission of hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matters.

Effect of piston bowl geometry and spray angle on engine performance and emissions in HCCI engine using multi‐stage injection strategy

AbstractThe homogeneous charge compression ignition (HCCI) and combustion chamber geometry play significant roles in improving the potential of compression ignition engines and their environmental sustainability. However, a major hindrance to the progress of HCCI technology has been the notable decline in brake thermal efficiency and emit high levels of hydrocarbon (HC) and carbon monoxide (CO) which is mainly due to the low temperatures during combustion and low post oxidation of these components. Combustion chambers like hemispherical combustion chamber (TCC) and toroidal combustion chamber (TCC) are known to provide better combustion characteristics due to their increased surface‐to‐volume ratio. Moreover, injection timing and spray position have shown a significant effect on the controlling onset of combustion and emission in HCCI engine. Therefore, the primary objective of this numerical study is to enhance the engine characteristics in HCCI mode using an HCC and TCC piston bowl geometry coupled with multistage injection and compare the results with flat piston bowl geometry. The results show that the toroidal shape piston geometry provides 3%–5% higher brake thermal efficiency compared to the conventional piston geometry. Additionally, the energy balance analysis revealed that the combination of modified piston geometry and multi stage injection improved the combustion process by reducing the energy losses due to incomplete combustion and heat transfer to the engine walls. These findings suggest that the proposed injection strategy combined with modified piston geometry has the potential to enhance the performance of HCCI engines and reduce their environmental impact.

Performance and Emission Analysis of Four-Stroke Diesel Engine Single Cylinder on Toroidal Piston Modification with B30 Fuel

Improvement of the performance of the diesel engine can be done by expanding the combustion chamber. One of the objectives of this research is to obtain optimal piston performance by modifying the piston crown to be 1mm deeper than the standard piston using B30 fuel. This research is also proof of previous research with a simulation that concluded that the performance of a diesel engine using a modified toroidal combustion chamber (TCC) +1mm piston has better performance than a standard piston. This research will analyze the comparison of the performance of a diesel engine using a standard piston and a modified piston on the diesel engine, using an experimental method with B30 biodiesel fuel with engine speed (RPM) variation of 1900 and 2100, also the dummy loads used are 1000, 2000, 3000, and 4000 Watts (W). From the results of the performance tests, it is concluded that the standard piston produces better performance than the modified piston with a very small difference in value in terms of torque, power, and SFOC. The level of NOx emissions produced by the standard RPM 1900 with 1000 W load is 1,483 g/KWh, at a load of 2000 W is 1,011 g/KWh, at a load of 3000 W is 1.375 g/KWh, at a load of 4000 W is 2,372 g/KWh, for standard piston RPM 2100 NOx emission levels produced at 1000 W load is 1,902 g/KWh, at 2000 W load is 1,450 g/KWh, at 3000 W load is 1.368 g/KWh, at 4000 W load is 1,066 g/KWh. The level of NOx emissions produced using a modified piston at 1900 RPM at 1000 W load is 1.865 g/KWh, at 2000 W load is 1.326 g/KWh, at 3000 W load is 1,250 g/KWh, at 4000 W load is 0.857 g/KWh, for RPM 2100 uses a modified piston at a 1000 W load is 1,970 g/KWh, at a 2000 W load is 1,583 g/KWh, at a 3000 W load is 1,465 g/KWh, at a 4000 W load is 1,226 g/KWh. NOx emission levels using standard pistons at RPM 1900 with B30 fuel tend to be smaller at low loads and larger at high loads compared to modified pistons, while NOx emission levels using standard pistons at RPM 2100 fueled by B30 are smaller than using a modified piston.

Hydrogen and dual fuel mode performing in engine with different combustion chamber shapes: Modelling and analysis using RSM-ANN technique

This study investigates the impacts of hydrogen (H2) induction along with injected liquid honne biodiesel (BHO)/uppage biodiesel (BUO) as secondary pilot fuel in diesel engine. The effects of compression ratio (CR), hydrogen fuel flow rate (HFR) and different combustion chamber shapes in dual fuel (DF) mode were investigated. In the first phase of experiments, the effects of three different CR (15.5, 16.5, and 17.5) on engine efficacy and emission were presented. In the second phase, the effects of three HFR (0.1, 0.17, and 0.24 kg/h) on engine efficacy and emission, as well as the maximum possible HFR were reported. In the last phase, performance with different combustion chambers i.e., Hemispherical Combustion Chamber (HCC), Toroidal Reentrant Combustion Chamber (TRCC), and Toroidal Combustion Chamber (TCC) at maximum possible CR and HFR was highlighted. The study revealed that for knock free operation of the DF engine, the highest probable HFR was 0.24 kg/h at a CR of 17.5, fuel IT of 27obefore top dead center (bTDC) and injector opening pressure (IOP) of 250 bar. The toroidal re-entrant combustion chamber (TRCC) shape yielded 8%–12% better brake thermal efficiency (BTE) with lower emissions but 20–29% higher oxides of nitrogen (NOx) at 80% load in DF mode as contrasted to the single CI mode. Both peak pressure (PP) and heat release rate (HRR) were 12–15% higher. Response surface methodology (RSM) was used to design the experiments and to carry the optimization process. Artificial Neural Network (ANN) was used to forecast the performance and emission behaviors of the test engine. The findings demonstrated that RSM and ANN were excellent modelling techniques with good accuracy. In addition, ANN's prediction performance (R2 = 0.975 for BTE) was somewhat better than RSM's (R2 = 0.974 for BTE). Both the techniques were found to be successful in terms of agreement with experimental findings with ratios varying from 95% to 98% respectively. The prediction of BTE and NOx was also carried using different machine learning algorithms. It can be seen that R2 value for these models were slightly lower than ANN and RSM models indicating good predicting capability of ANN modelling.

Novel Petit grain bitter orange waste peel oil biofuel investigation in diesel engine with modified fuel injection pressure and bowl geometry

The novelty of the present work deals with the experimental investigation of a novel biofuel feedstock as an alternative energy source that has not acquired much consideration among the researchers. The study for a novel biofuel feedstock resulted in Petit grain bitter orange oil as a prime source for biofuel production through steam distillation. The fuel properties of Petit grain bitter orange oil biofuel (PF) were determined by standard testing procedures. Further, FTIR, GC–MS, and TG/DTG analyses were performed to explore the functional groups, chemical composition, and thermal analysis, respectively. PF was experimentally examined in a single cylinder diesel engine at 1500 rpm for its performance, emission, and combustion characteristics. PF showed minimum emission, but performance and combustion characteristics were found higher with diesel. Therefore, the engine operating conditions were modified: bowl geometry profile (hemispherical and toroidal combustion chamber) and fuel injection pressure (190, 210, 230, and 250 bar). Improved engine characteristics were observed with PF in the toroidal combustion chamber at advanced IP (250 bar). Further, Diesel-RK-a specialized simulation software was employed to analyze flow with engine characteristics of both fuels considered. From the investigation, PF may be viewed as a choice of low viscous renewable fuel to produce power in engines with low emissions to create a more sustainable and cleaner environment.

Exploration of engine characteristics in a CRDI diesel engine enriched with hydrogen in dual fuel mode using toroidal combustion chamber

The impact of dual fuel (diesel/hydrogen) on different performance aspects of CRDI diesel engines is investigated in this study. Amongst the fuel alternatives for IC (internal combustion) engines, the research described in this study recommended hydrogen as the least polluting and renewable in the long term. A CNG-LPG injector feeds hydrogen into the intake manifold, while diesel injectors pump pilot diesel to a DI engine adapted to hydrogen and diesel (dual-fuel mode). By maintaining 5.2 KW of consistent IP (Indicated Power) and engine speed at 1500 ± 10 rotations per minute (RPM), the hydrogen energy was varied in the dual fuel at 0% (100% diesel), 6%, 12%, 18% and 24%. With the increase in H2 energy proportion, a decrease (5.2% decrease at 24% HES) in the BSEC (brake specific energy consumption) and the engine's BTE (brake thermal efficiency) is improved (7.85% increase at 24% HES). When emissions are considered, indicated NOx increased (3.42%) while indicated CO2 (3.61%), CO (2.84%), and smoke (4.85%) decreased with an increase in the proportion of hydrogen. Along with this, it was noted that the peak HRR (heat release rate) of 69.8 J/deg and in-cylinder pressure of 80.8 bar which increased significantly with the increase in hydrogen rate.

Effect of novel fuel vaporiser technology on engine characteristics of partially premixed charge compression ignition (PCCI) engine with toroidal combustion chamber

Partially pre-mixed charge compression ignition (PCCI) and combustion chamber geometry are significant factors that improve the potential of compression ignition engines and the sustainable effect on the environment. The considerable decline in brake thermal efficiency in PCCI has always been a point of halt in the progress of this technology. The toroidal combustion chamber (TCC) has proved its effectiveness in enhancing the performance characteristics of a conventional engine. The primary aim of this experiment is to improve the engine characteristics for PCCI mode when it operates with a TCC piston bowl geometry and compare the behavior with the conventional direct injection (DI) technology. A novel fuel vaporiser technology is developed and retrofitted in a single-cylinder DI diesel engine in this work. A comparative study on the effect of combustion chamber geometry (hemispherical and toroidal) on engine characteristics was performed and the engine setup was operated in conventional and PCCI mode. The PCCI mode was tested by using fuel vapour induction in intake manifold via the fuel vaporizer unit. Liquid diesel fuel was heated up to its vaporization temperature and sent to the intake manifold, wherein fresh air was mixed with vaporized fuel, forming an external mixture that enters the combustion chamber. The different vapour induction rates (2 ml/min and 4 ml/min) were used to understand the changes in combustion behavior. Compared to conventional, the PCCI mode proved its worth in limiting NOx emission with 7 g/kW-h reduction at 4 ml/min vapour induction rate with HCC at moderate engine load. Diesel vapour induction rate of 2 ml/min along with TCC piston resulted in improved engine characteristics with a marginal decrement in BTE by 1.2%, significant decrease of NOx by 5 g/kW-h at moderate engine load. Moreover, at full engine load, the PCCI anomaly is observed as the rate of pressure rise (ROPR) surpasses the conventional by 2 bar/deg for 2 ml/min induction rate with HCC, thereby favouring conditions for engine knock. Overall, the brake thermal efficiency limitations in PCCI can be countered by TCC piston bowl geometry; however, the PCCI usage is limited to a specific vapour flow rate and engine load range.

CFD Analysis of piston bowls geometry for CI direct injection engine using finite element analysis

Both NOx and soot emissions are major concerns in compression ignition (CI) engine with diesel fuel and the enhancement of variety of fuel and air can increase the performance of combustion engine. There are several methods to enhance the variety of air-fuel within the cylinder. Altering the geometry of piston bowl is one of the methods to improve the air-fuel mixture. This article proposes the effect of piston bowl geometry on the direct injection diesel engine performance and emissions, where various profiles of piston bowl referred as hemispherical combustion chamber (HCC), toroidal combustion chamber (TCC) and shallow depth combustion chamber (SCC) are designed using computer aided design and drafting (CADD) tool and ANSYS workbench is adopted for analysis. In addition, Karanja oil mixed with base fluid diesel at different volume fractions like0.2%, 0.3% and 0.4% and are calculated for their combination properties. Further, theoretical calculations are considered to determine the properties of Nano fluids which are later used as inputs for the analysis. Finally, CFD analysis is employed on different geometries at different fluid volume fractions and thermal analysis is done for piston bowl geometries with different composite materials like carbon fiber and armide fiber.

Effects of hydrogen flow rate, injection pressure and EGR on performance of common rail direct injection (CRDi) engine in dual fuel mode

PurposeThe different performance tests were conducted on diesel engine compression ignition (CI) mode and CRDi engine.Design/methodology/approachThe 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).FindingsThese 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/valueThe 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.

Investigation of partially pre-mixed charge compression ignition engine characteristics implemented with toroidal combustion chamber and exhaust gas recirculation

ABSTRACT Many pre- and post-treatment strategies have been instigated in compression ignition engines to meet the stringent vehicular emissions norms. The partially pre-mixed charged compression ignition (PCCI) combustion technique has shown a significant reduction in emissions without much affecting the efficiency of the conventional diesel engine by emitting low nitrogen oxides and smoke emissions simultaneously. However, the PCCI engine has also shown some limitations by producing higher hydrocarbon (HC) and carbon monoxide (CO) emissions from the engines. The toroidal combustion chamber has proven its potential to reduce the HC and CO emissions from the conventional engine. Therefore, in the current experimental study, PCCI engine characteristics were investigated with toroidal piston geometry and compared with conventional engine characteristics having hemispherical combustion chamber (HCC). The experiments were performed on single-cylinder, four strokes, direct injection, diesel engine modified to operate on PCCI mode. The homogeneous mixture for PCCI combustion was obtained with an external mixture formation technique with a fuel vaporizer (retrofit device). The tests were conducted with 15% and 30% diesel vapor without and with 10% exhaust gas recirculation and then compared with the conventional engine. The investigation results show that better air–fuel mixing results in low engine emissions. NOx emissions were reduced by 29% and 36%, and smoke opacity was decreased by 33% and 38% with 15% and 30% diesel vapor with EGR with a marginal decrement in thermal efficiency compared to conventional engine.

Retraction Note to: Effect of piston bowl geometry modification and compression ratio on the performance and emission characteristics of DI diesel engine

The present study describes the experimental investigations carried out to study the influence of modified piston bowl geometry at a constant speed of the combustion, performance and emission characteristics of a direct injection compression ignition diesel engine. The modified piston profiles, namely hemispherical combustion chamber (HCC) and toroidal combustion chamber (TCC), are manufactured with a baseline compression ratio of 17:1, and the effects of compression ratio (16:1, 17:1 and 18:1) are analyzed. Experiments are carried out with pure diesel for low load to full load conditions for better understanding. With an increasing compression ratio of the engine, TCC piston geometry has shown better improvement in brake thermal efficiency, carbon monoxide and hydrocarbon emissions than HCC. However, a slight penalty in NOx emission is observed with increasing compression ratio and TCC piston geometry. In-cylinder peak pressure, net heat release rate and rate of pressure rise are increased significantly with increasing compression ratio and the use of TCC geometry.

RETRACTED ARTICLE: Effect of piston bowl geometry modification and compression ratio on the performance and emission characteristics of DI diesel engine

The present study describes the experimental investigations carried out to study the influence of modified piston bowl geometry at a constant speed of the combustion, performance and emission characteristics of a direct injection compression ignition diesel engine. The modified piston profiles, namely hemispherical combustion chamber (HCC) and toroidal combustion chamber (TCC), are manufactured with a baseline compression ratio of 17:1, and the effects of compression ratio (16:1, 17:1 and 18:1) are analyzed. Experiments are carried out with pure diesel for low load to full load conditions for better understanding. With an increasing compression ratio of the engine, TCC piston geometry has shown better improvement in brake thermal efficiency, carbon monoxide and hydrocarbon emissions than HCC. However, a slight penalty in NOx emission is observed with increasing compression ratio and TCC piston geometry. In-cylinder peak pressure, net heat release rate and rate of pressure rise are increased significantly with increasing compression ratio and the use of TCC geometry.

Optimisation of nozzle geometry in the modified common rail direct injection biodiesel-fuelled diesel engine

The study of the experimental work focused on the optimisation nozzle geometry in the modified common rail direct injection (CRDI) diesel engine powered with palm oil methyl ester (POME) fuel. The CRDI diesel engine modified in terms of the toroidal re-entrant combustion chamber (TRCC) shape and nozzle geometry. The experiments are conducted with POME and diesel fuels (DF) at 80% and 100% loads, respectively. The parameters, such as compression ratio (CR) 17.5, speed 1500 RPM, fuel injection timing (IT) 10° BTDC and 900 bar injection opening pressure (IOP), are maintained constant. The selected fuel IT and IOP were optimised in our previous research. The experiments results revealed that the 7-hole nozzle injector improved in break thermal efficiency (BTE) by 1.5% and 1.3% for diesel and POME, respectively, as compared to the 6-hole injector. The average percentages of emissions are reduced up to 7.24% and 7.81% for diesel and POME fuels, respectively, except oxides of nitrogen (NOx). The peak pressure (PP) and heat release rate (HRR) are improved by 2.40% and 3.65%, respectively, for DF. The similar increased trend of PP and HRR is 2.53% and 4.10%, respectively, for POME in the modified CRDI diesel engine.

Performance, Combustion and Emission Characteristics of Direct Injection Diesel Engine Fueled With Castor Oil Methyl Esters and Ethanol Blends Equipped With 6 Hole Nozzle

Depletion of fossil fuel reserves and stringent pollution norms has created a need for search alternate source that can fuel internal combustion engine. The fuels obtained from green matter has got great potential to replace conventional fossil fuels to power internal combustion engine (ICE). But the performance of the ICE are influenced by many parameters such as injector opening pressure, injection timing, and combustion chamber profile. Current work deals with evaluation of engine performance, combustion characteristics of direction injection diesel engine fitted with re-entrant toroidal (RET) combustion chamber equipped with six hole nozzle fueled with castor oil methyl esters (CAOME) and ethanol blends. The peak value of break thermal efficiency (BTE) is found to be 26.34% at 75% load for a blend 80D+5B+15E with minimum emissions and with combustion duration and ignition delay in comparison with diesel.

Characterization study on performance, combustion and emission of nano additive blends of grapeseed oil methyl ester fuelled CI engine with various piston bowl geometries

The present work studies the outcome of various piston bowl geometries like shallow depth combustion chamber (SCC), toroidal shaped combustion chamber (TCC) and hemispherical shaped combustion chamber (HCC) in a compression ignition engine energized with diesel and grapeseed oil methyl ester with nano additives. The non-edible oil selected for the present investigation is grapeseed oil which was derived from winery waste. After single step transesterification with sodium hydroxide and methanol, grapeseed oil methyl ester was produced, and 100% of this biodiesel was further blended with optimized Zinc oxide nano particles of 100 ppm to reduce the NO emissions. Tests were conducted in 5.2 kW at 1500 rpm, single cylinder diesel engine. Performance, combustion and emission characteristics were studied for three sorts of combustion chamber geometry using grapeseed oil biodiesel with zinc oxide nano particles. Brake thermal efficiency turned out to be higher for toroidal combustion chamber in comparison with the other two designs of combustion chamber geometry. Also, other emissions like CO, HC and smoke were lower with toroidal shaped combustion chamber geometry. Considering the engine analysis, the toroidal shaped combustion chamber geometry was found to be better than shallow depth and hemispherical combustion chamber at all operating load conditions. The NO emissions were also found to be 13.2% lesser at full load operation for grapeseed oil methyl ester with zinc oxide nano particle blend.

Experimental investigations on direct injection diesel engines using grape seed oil methyl ester with different bowl geometries

ABSTRACTIn this paper, the performance of direct injection diesel engine was experimentally investigated under the influence of two different pistons’s geometry deep bowl combustion chamber (DBCC) and toroidal combustion chamber (TCC) compared with standard piston combustion chamber (SPCC) geometry. The experiments were carried out standard atmospheric conditions of 1.01325 bar and 30 ± 2 °C. The piston bowl was designed and developed without modifying the compression ratio of the engine. The investigations were carried out with B25 (25% GOME + 75% diesel), B50 (50% GOME + 50% diesel), B75 (75% GOME +25% diesel) and B100 (100% GOME) by volume blends for three different bowl geometries. The thermogravimetric analysis (TGA) was given the importance of higher in-cylinder temperature for the mass change of GOME leads to a more premixed phase of combustion. The results showed that DBCC has better combustion characteristics when compared with SPCC and TCC for all the blends. The B25 and B50 blends showed good combustion characteristics with DBCC and SPCC individually. While TCC showed average engine characteristics for all the blends categorically, the brake thermal efficiency for B25 blend confirmed a 4.7% higher than SPCC-diesel with DBCC piston, and the smoke, CO (Carbon monoxide), and HC (Hydrocarbon) are reduced by 9.2%, 30.7%, and 4.6%, respectively. Thus, the B25 blend in a DBCC piston engine was observed to be the distinction than other configurations. The results confirmed that the DBCC is a good option for B25 blend.

Effect of combustion chamber bowl geometry modification on engine performance, combustion and emission characteristics of biodiesel fuelled diesel engine with its energy and exergy analysis

With deteriorating energy reserves, rising environmental apprehensions and progressively more firm energy regulations have made renewable energy resources as an extremely attractive alternative source for near future. Biodiesel was considered as one of the promising energy resource for diesel engines. In the present work, non-edible oils namely pumpkin seed oil and Moringa oleifera oil were converted into methyl ester of Pumpkin seed oil (B1) and Moringa oleifera oil (B2) using transesterification process. The engine modification technique was said to be one of the current development in the field of the engine research motivating to achieve complete combustion. Two novel bowl geometries namely Toroidal Combustion Chamber (TCC) and Trapezoidal Combustion Chamber (TRCC) were developed and compared with standard Hemispherical Combustion Chamber (HCC). Further, the work was progressed to exergy and energy analysis. Amongst the bowl geometries, TCC showed better engine characteristics than TRCC and HCC. High swirl and squish behaviour of TCC engine helps in better air-fuel mixing and leads to complete combustion. Biodiesel samples contain oxygen molecules in its structure, reduced engine exhaust emissions except NOx were observed. On the whole, B1 may be considered as the promising alternative fuel as it exhibited 66.51% of exergy efficiency in TCC engine.