Diesel-biodiesel Mixtures Research Articles

Production of oxy-hydrogen with an alkaline electrolyzer, and its impacts on engine behaviors fuelled with diesel/waste fish biodiesel mixtures supported by graphene-added nanofuels

Because of the high viscosity, low calorific value, atomization, and vaporization problems of biodiesel, addition of nano additives with oxyhydrogen is encouraged to improve engine combustion and emissions. Waste fish methyl ester was blended with diesel oil in 20%, and then nano graphene was added to diesel-biodiesel mixtures at doses of 25, 50, and 100 mg/L. An alkaline electrolyzer was employed to generate oxyhydrogen gas at a rate of 0.5 liters per minute through water electrolysis. At 3000 rpm rated speed and engine load range from 25 to 100% with the interval of 25% were investigated. Mixtures of graphene in methyl ester combinations have increased the thermal efficiency of biodiesel blend by 11%, 13%, and 15%, respectively, when supplemented with HHO. The addition of 25, 50, and 100 ppm of graphene to the methyl ester was mixed along with oxyhydrogen, resulting in notable reductions of CO emissions by 18%, 22%, and 25% for WF20. Significant decreases in HC emissions by 29%, 32%, and 38%, accompanied by noticeable declines in smoke concentrations of 25%, 28%, and 33% for WF20G25 + HHO, WF20G50 + HHO, and WF20G100 + HHO were shown. Moreover, NOx emissions experienced reductions of 20%, 24%, and 29% when HHO was added to methyl ester blends containing 25, 50%, and 100 ppm of graphene, respectively. Incorporating biodiesel from waste fish oil, enriched with 100 ppm graphene with HHO shows potential for lowering exhaust emissions, and enhancing engine performance and combustion characteristics, particularly for the commonly used biodiesel with poor fuel properties.

Evaluating the vibrational properties of an engine powered by diesel–biodiesel mixtures containing aluminum oxide nanoparticles

Much research has been done on the performance and emissions of engines using renewable fuels. In some cases, nano additives have been added to these fuels. Although the research results are essential, these fuels should be considered from other aspects. One of these aspects is engine vibrations, which can be related to engine ignition and knocking. In this research, the vibration of an engine and its relationship with knocking and combustion using diesel and alumina nano additives with 30, 60, and 90 ppm dosages in the diesel–biodiesel blend (B5, B10) were evaluated. Experiments were carried out using precise vibration measurement equipment in a single-cylinder, four-stroke engine. The frequency domain transformation, Welch test, Kurtosis, and RMS of acceleration were used to analyze the vibrations. The advantages and disadvantages of each method were investigated on the vibrations of each fuel blend. The results showed that despite being more complicated, the Welch test better shows the difference between fuels and their vibration. By this method, it was found that diesel fuel has the lowest vibrations at frequencies below 10 kH, but it has the highest vibrations at frequencies above 10 kH. Also, with diesel and adding alumina nanoparticles to the fuels of B5, the engine performance becomes more erratic despite increasing engine power.

Vibration analysis using wavelet transformation technique and performance characteristics of a diesel engine fueled with tamarind biodiesel-diesel blends and diverse additives

This study investigates the combustion, performance characteristics, and emission levels of diesel and tamarind biodiesel mixtures (B20, B30, B40, and B100) in a single-cylinder, four-stroke, direct injection (DI) diesel engine. Further, two fuel additives, namely Butylated Hydroxytoluene (BHT) (an antioxidant) and Diethyl ether (DEE) (a cetane improver), were separately added to B20 to enhance the engine characteristics. In addition, Wavelet Transform and Wavelet Packet algorithms were used to investigate the vibration behaviour of the tested fuels. The results demonstrate that the B20 blend improved the performance and generated less emission than the other blends. Moreover, the brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) for B20+BHT were 3.8% higher and 4.1% less than B20, respectively. B20+DEE combustion showed lower CO and smoke pollutants by 51% and 19% compared to B20, respectively. The NOx emissions for the blends containing BHT and DEE were decreased by 16% and 9%, respectively. The engine vibration analysis showed almost the same frequency with fuel blends B20 and B30, which were similar to the diesel fuel values. The results concluded the tamarind biodiesel/diesel mixtures with BHT and DEE improved the performance and emissions behaviors of DI diesel engine and could be considered a potential alternative biofuel for such engines. Wavelet analysis of the engine was accurately employed to extract the prominent features of the vibrations.

Effective utilization of waste pork fat as a potential alternate fuel in CRDI research diesel engine – Waste reduction and consumption technique

This work utilized the conventional transesterification process to convert waste pork fat into pork fat biodiesel. The produced biodiesel was meant to serve as a diesel fuel substitution for common rail direct injection (CRDI) diesel engines. Butylated Hydroxytoluene (BHT) as an antioxidant doping with waste pork fat biodiesel-diesel blend has not been analyzed in CRDI diesel engines. Therefore, to improve the ignition process and reduce the engine exhaust emissions in a research CRDI diesel engine, the BHT was employed to combine with diesel-biodiesel mixtures in this work. BHT antioxidants are partially mixed (BHT 50, 100, and 150 ppm) to improve the physicochemical qualities of test fuel and enhance the combustion process of diesel-biodiesel blends (B20). The antioxidant purity was analyzed by energy dispersive X-ray analysis (EDX), structures were analyzed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyzer spectrograph was utilized to study the biodiesel chemical components. After mixing the BHT, the overall phase of the base fuel remained constant. The experiment outcomes revealed that the biodiesel had higher cylinder pressure than the other test fuels, and the BHT100 ppm blend had a higher heat release rate (HRR). B20BHT100 blend shows 3.98% higher brake thermal efficiency (BTE) at full load operation than pure biodiesel but lowered to diesel fuel. Biodiesel (B100) decreases the smoke opacity by 4.5% compared to diesel fuel. BHT has been incorporated into the biodiesel blend to minimize oxides of nitrogen (NOx) emissions at all loads. The B20BHT150 blend decreased NOx emissions by 5.06% more than diesel fuel at maximum load. Compared to pure biodiesel, the B20 blends reduce carbon monoxide (CO) emissions by 7.1% and hydrocarbon emission (HC) by 12.5%. This research found that adding BHT to biodiesel blends lowers NOx emissions with a slight impact on performance.

UV irradiation testing of biodiesel from the Alhagi oil and diesel-biodiesel mixtures

The chemical stability of fuels is one of the key factors in ensuring the proper operation of combustion engines. Progressive destruction of components of diesel-biodiesel fuels during storage and transportation can adversely affect their physical and chemical parameters. Besides, the destruction of petroleum products under sunlight and the formation of toxic compounds have ecological importance. The purpose of the presented work is to investigate the influence of UV irradiation (λ = 300–450 nm) on the chemical content of petroleum diesel and B5, B10, B20, B50, and B100 fuel blends for the 24 h. As biodiesel, the product of transesterification of non-edible Alhagi oil with methanol was used. Chemical changes after irradiation were controlled by the BRUKER FT NMR spectrometer. The relationship between changes in the chemical composition and important physicochemical parameters (density, viscosity, flash point, and cetane index), before and after photochemical destructions was discussed. Based on the obtained results, it was determined that the B20 fuel mixture has more chemical stability after UV irradiation than conventional diesel and other diesel-biodiesel mixtures.

Design and evaluation of surrogate mixtures for diesel based on the isolated droplet configuration

The development of simplified surrogate mixtures able to replicate combustion-related behaviors of chemically complex fuels is essential for their simulation with computational tools, a key step towards the design of high-efficiency and low-emission combustion applications. This work proposes to use the isolated droplet configuration as a benchmark to formulate and validate surrogates that capture the vaporization and soot production characteristics of a first-fill diesel and a diesel-biodiesel mixture. To that end, droplet vaporization experiments and a multicomponent model were coupled to produce blends matching the evaporation behavior, whereas the soot tendency was incorporated through tests at the ASTM D1322 smoke point lamp and the Oxygen Extended Sooting Index (OESI). The so-obtained surrogate blends were subsequently validated for both characteristics. Their evaporation curves proved to match remarkably well those obtained for the target fuels, with noticeable improvements when increasing the number of compounds in the mixture. As for the sooting behavior, the proposed blends achieved a good emulation in terms of the design parameter (OESI), confirming the validity of the proposed methodology. On the other hand, an additional and independent validation of the sooting propensity through the quantification of the mass of soot produced by isolated droplets under a high-temperature and reducing atmosphere revealed significantly higher soot yields for the surrogates when compared to the target fuels. These results highlight the relevance of the configuration used when designing and validating surrogates, since the same blends can provide substantial differences when evaluated through different sooting indices.

Experimental design to study corrosivity of diesel-biodiesel mixtures on microalloyed steel

Material selection is a crucial part of industrial process and the analysis of the effects of operational variables on the corrosion plays an important role. The present study was undertaken to evaluate the corrosion of a microalloyed steel in contact whit diesel-biodiesel mixtures. A design of experiments, the analysis of variance (ANOVA) and surface response methodology (SRM) were used in order to evaluate the corrosivity of the fuel mixtures in contact with steel. The effect of biodiesel concentration, addition of multifunctional additive and immersion time were the evaluated factors to research the corrosion behavior of microalloyed API X70 steel. The response used in the exploitation of the design was the corrosion rate; it was assessed through gravimetric measurements on samples. The results of the gravimetric tests showed that the immersion time has the most significant effect on corrosion resistance, following of additive and biodiesel concentration. ANOVA and SRM revealed a decrease in the corrosion rate with immersion time, effect that suggests the formation of a protective layer on the metallic surface. It can also be concluded that the use of lignin promoted the reduction of corrosive processes, especially when mixed with biodiesel; this result was corroborated by microscopy analysis.

Optimization of formulation for surrogate fuels for diesel–biodiesel mixtures

Optimization of formulation for surrogate fuels for diesel–biodiesel mixtures

Combustion, Performance, and Emission Behaviors of Biodiesel Fueled Diesel Engine with the Impact of Alumina Nanoparticle as an Additive

The objective of this research work is to evaluate the performance, combustion, and exhaust emissions of a variable compression ratio diesel engine utilizing diesel 25% rubber seed biodiesel mixture (B25) blended with 25 ppm and 50 ppm of alumina nanoparticle running with different operating conditions. An ultrasonicator was used to make uniform dispersion of alumina (Al) nanoparticles in the diesel–biodiesel mixture. Biodiesel mixture blended with nanoparticles has physicochemical characteristics that are comparable to ASTM (American Society for Testing and Materials) D6751 limitations. The results revealed that the B25 exhibited a lower cylinder peak pressure and lower HRR (heat release rate) than diesel at maximum power. BTE (brake thermal efficiency) of B25 is 2.2% lower than diesel, whereas BSFC of B25 is increased by 6% in contrast to diesel. Emissions of HC (hydrocarbon), CO (carbon monoxide), and smoke for B25 were diminished, while emissions of NOx (nitrogen oxide) were higher at maximum power. Further, the combustion and performance of diesel engine were improved with the inclusion of alumina nanoparticles to biodiesel blends. In comparison to B25, BTE of B25 with 50% alumina nanoparticles (B25Al50) mixture was enhanced by 4.8%, and the BSFC was diminished by 8.5%, while HC, CO, and smoke were also diminished by 36%, 20%, and 44%, respectively. At peak load, the maximum cylinder pressure and HRR of B25 were improved by 4.2% and 6.7%, respectively, with the presence of 50% alumina nanoparticles in a biodiesel blend (B25Al50).

Numerical simulation of the performance and emission of a diesel engine with diesel-biodiesel mixtures

Among the alternative fuels, biodiesel is considered as a sustainable option for diesel engine. In this study, the methyl ester of waste cooking oil was produced using the transesterification method. The suggested biodiesel is mixed with different percentages (5% and 10%) on a volume basis together with diesel fuel and tested in on a four cylinder, four stroke, direct injection, diesel engine at different engine speeds (1100 to 1400 rpm at an interval of 100 rpm) under full load in the faculty of mechanical engineering, nowshahr imam Khomeini university of marine sciences. The experimental side is verified with simulation study done by GT-Power software, which shows very good agreement between simulation and experimental result, more specifically variation of only up to 6.3% in torque, 4.8% SFC and 5.6% in NOx and CO was found. The simulation results showed by increasing the engine speed and higher biodiesel to diesel ratios for biodiesel (B10), torque increased by 4.4%, whereas specific fuel consumption (SFC) decrease by 4.45%. Also, compared to the diesel fuel, NOx increased by 1.8%, whereas CO decreased by 37.67%. The simulation and experimentally results revealed that overall B10 provides better performance and significantly reduced engine emissions. Therefore, the simulation work due to lower costs and increased computational speed compare to the experiments can reduce the cost of research.

Experimental Investigation for the usage of Diesel - Jatropha – Rice bran Biodiesel Mixture Blends in Four Stroke Diesel Engine

In last few decades, the demand of fossil fuel increases due to the enormous increases in vehicle population. There is a shortage of crude oil supply due to the excess need of fossil fuel. This urges the researchers to switch to renewable resources, like biofuels. Biodiesels can be produced successfully from plants such as palm, jatropha, rapeseed, rice bran, soyabean, corn etc. The use of biodiesel will considerably reduce the emissions also and thus increases the engine performance. The oil is converted to biodiesel with the help of trans-esterification process. The properties, emission characteristics and performance for the Compression Ignition (CI) of the fuel process are examined for biodiesel which is blended with two oils (rice bran and Jatropha oil blend mixture) by using this experimental study. The results indicate that the calorific value forthe dual blends of biodiesel decreases with an increase in biodiesel concentration in the blends of diesel-biodiesel mixture. It is found that the brake thermal efficiency is lower for biodiesel blends. For higher ratio of blends, biodiesel blends givelower HC and NOx emissions.

Effect of Higher Alcohol (Pentanol-Heptanol)–Biodiesel–Diesel Fuel Blends on the Performance and Emission Characteristics of a Direct-Injection Diesel Engine’s

Alternatives of fossil fuel resources as renewable biodiesel fuel and alcohols represents latest technology to be developed associated with the declining of fossil fuel resources along with higher crude oil price. In this study, four-stroke, single cylinder, and direct injection diesel engine performance and emissions are evaluated. The engine was running at variable speeds (1600-3000 rpm). 15% and 25% of pentanol and heptanol were added to the diesel-biodiesel mixture. The experimental results showed increasing in brake specific fuel consumption with the increasing of higher mass fractions of alcohol blends, which is attributed to the decreasing the lower heating value (LHV) of the blends. Higher brake thermal efficiency compared to diesel fuel was produced. An expressive reduction in carbon monoxide (CO) of (16.1% - 46.6% vol.) with total unburned hydrocarbons (UHC) decrease of (7.4% - 25.3% ppm), and nitric oxides (NOx) of (8.5% - 23.5% ppm). Biodiesel and alcoholic blends are suitable to be used as alternatives to diesel without the need for any modifications in conventional diesel engines.

An Extensive Analysis of Biodiesel Blend Combustion Characteristics under a Wide-Range of Thermal Conditions of a Cooperative Fuel Research Engine

Examining the influence of thermal conditions in the engine cylinder at the start of fuel injection on engine combustion characteristics is critically important. This may help to understand physical and chemical processes occurring in engine cycles and this is relevant to both fossil fuels and alternative fuels like biodiesels. In this study, six different biodiesel–diesel blends (B0, B10, B20, B40, B60 and B100 representing 0, 10, 20, 40, 60 and 100% by volume of biodiesel in the diesel–biodiesel mixtures, respectively) have been successfully tested in a cooperative fuel research (CFR) engine operating under a wide range of thermal conditions at the start of fuel injection. This is a standard cetane testing CFR-F5 engine, a special tool for fuel research. In this study, it was further retrofitted to investigate combustion characteristics along with standard cetane measurements for those biodiesel blends. The novel biodiesel has been produced from residues taken from a palm cooking oil manufacturing process. It is found that the cetane number of B100 is almost 30% higher than that of B0 and this could be attributed to the oxygen content in the biofuel. Under similar thermal conditions at the start of injection, it is observed that the influence of engine load on premixed combustion is minimal. This could be attributable to the well-controlled intake air temperature in this special engine and therefore the evaporation and mixing rate prior to the start of combustion is similar under different loading conditions. Owing to higher cetane number (CN), B100 is more reactive and auto-ignites up to 3 degrees of crank angle (DCA) earlier compared to B0. It is generally observed in this study that B10 shows a higher maximum value of in-cylinder pressure compared to that of B0 and B20. This could be evidence for lubricant enhancement when operating the engine with low-blending ratio mixtures like B10 in this case.

Analysis of 1H NMR spectra of diesel and crambe biodiesel mixtures using chemometrics tools to evaluate the authenticity of a Brazilian standard biodiesel blend

A methodology was developed to monitor the content of crambe biodiesel in mixtures with conventional diesel using hydrogen nuclear magnetic resonance (1H NMR) spectroscopy combined with the orthogonal projections on the latent structure-discrimination analysis (OPLS-DA). The efficiency of the developed OPLS-DA model was analyzed based on the criteria of true response statistics: false positive and false negative rate, sensitivity, specificity, efficiency and Matthew's correlation coefficient, where the sensitivity (true positive rate) and specificity (true negative rate) were both equal to 1 and the false positive and false negative rates were both equal to 0, which means that all samples to be predicted as belonging to the diesel class of interest, B10 (containing 10% biodiesel and 90% pure diesel), were predicted in class 1, and all samples to be considered as belonging to the diesel class, not of interest, BX (biodiesel content less and greater than in B10), were predicted in class 0. These results showed 100% correct classification of the training and test set samples for B10 and BX, demonstrating a high efficiency of the OPLS-DA model in the monitoring of crambe methyl biodiesel content when mixed with diesel in various proportions. The excellent results in the application of this model suggest that this analytical methodology is feasible, efficient and suitable for use by inspection agencies to control the quality of this fuel.

An experimental analysis of performance and exhaust emissions of a CRDI diesel engine operating on mixtures containing mineral and renewable components

The manuscript presents a comparative analysis of the performance and emission characteristics of a compression ignition engine equipped with a Common Rail injection system. The engine is fueled with diesel-biodiesel mixtures containing 25% and 50% share (by volume) of renewable components. Conventional diesel is used as a reference. Turkey lard and rapeseed oil are used as raw materials and subjected to the single-stage transesterification process to obtain methyl esters. The experiments are performed on a medium-duty, turbocharged, inter-cooled, Common Rail Direct Injection (CRDI) diesel engine. This study concentrates on one engine speed of 1500 rpm, typical for gen-set applications, and mid-load range from 100 Nm to 200 Nm. The scope of measurements covers the analysis of exhaust gasses concentration and engine efficiency parameters. In addition, the in-cylinder pressure measurements are performed in order to provide insight into the differences in combustion characteristics between examined fuel mixtures. The study reveals that the addition of the renewable component to fuel mixture positively affects a number of examined performance parameters as well as decreases the concentration of the examined toxic exhaust components, in the majority of cases.

Biodegradability and microbial community investigation for soil contaminated with diesel blending with biodiesel

Due to intensified usage of diesel-biodiesel blending oils, solving potential contamination problems becomes crucially important. The objective is to investigate various percentages of diesel-biodiesel mixtures caused contamination and remediation approaches, including bioaugmentation with seven proved diesel-degrading bacterial species. Degradation of 80%-99% was achieved with the proposed remediation approach. The TPHd degradation efficiency (%) and rates (k) in the control batch (CT) found either similar or superior to the bioaugmentation batch (BA). The batches with 20% and 50% biodiesel achieved 10% improvement of TPHd degradation in CT over BA. The TPHd degradation was enhanced by the increase of biodiesel. For example, degradations of 99% were achieved in the soil polluted with 100% biodiesel. The increase of the biodiesel enlarged the total heterotrophic bacterial counts from 107 to 109 CFU/g dry soil. The molecular data concluded Gordonia alkanovorans and Gordonia desulfuricans were most dominant in the indigenous community. Pseudomonas aeruginosa was a strong survivor last for the entire remediation. The growth patterns of bacteria indicated the introduced species were useful only in the beginning. Using the recommended molecular tools to identify the useful bacteria prior to a remediation project would be helpful in reducing the cost and determine a wise remediation strategy.

Numerical simulation of the performance of a diesel cycle operating with diesel-biodiesel mixtures

This paper conducted a numerical simulation of the thermodynamic cycle of a diesel engine, which runs on diesel/biodiesel mixtures, and takes the processes of compression, combustion and expansion into account. The zero-dimensional mathematical model was adopted in order to build the numerical modeling based on the First Law of Thermodynamics and also of the state equation in order to obtain the pressure and temperature profiles of gases inside the cylinder which vary depending on the angle of the crankshaft. The mathematical modeling included taking account of the transfer of heat through the walls, the energy released during combustion considering the Wiebe function, the thermophysical properties of the reagents and the products and the geometric parameters of the engine. The largest relative error found was the 2% in the pressure which showed a good agreement between the simulated and experimental results from previous studies. A parametric analysis was performed considering the fraction of diesel and biodiesel in the mixture, the start angle of the combustion and the equivalence ratio with a view to assessing their effect on the performance of the engine. The results show that a reduction in temperature and in pressure values was achieved when the biodiesel share in the mixture is increased. This led to altering the values of the performance parameters values. In addition, the peaks of pressure and temperature were increased by raising the equivalence ratio which brings forward the point at which the fuel starts to burn due to the increases in the pressure and maximum temperature. It was verified that Wiebe function parameters have a direct influence not only on the pressure and temperature values but also on the performance data of the engine.

An experimental study on using diethyl ether in a diesel engine operated with diesel-biodiesel fuel blend

Although biodiesel has a promising potential to be used as an alternative fuel for compression-ignition engines, its use may deteriorate engine performance. The objective of the current study was to enhance the performance of a compression-ignition engine operated with a diesel-biodiesel blend using diethyl ether (DEE). Four fuels were examined in a diesel engine to assess its performance and analyze the combustion process. These fuels were diesel, biodiesel-diesel mixture, and two mixtures of biodiesel-diesel-DEE with DEE proportions of 5% and 10% by volume. It was found that using diesel-biodiesel blend increased the minimum brake specific fuel consumption (bsfc) and reduced the maximum thermal efficiency by 8.1% and 6.8%, respectively, compared to diesel fuel. However, employing 5% DEE in the diesel-biodiesel mixture improved engine performance considerably for most engine loads in comparison with all fuels. Altering the fuel type had no significant impact on combustion start instant. However, the heat release rate was lower and combustion duration was longer for diesel compared to other fuels at higher engine loads. Using DEE did not significantly affect engine stability.

Theoretical and experimental study on the performance of a diesel engine fueled with diesel–biodiesel blends

This study reports the effects of engine load and biodiesel percentage on the performance of a diesel engine fueled with diesel–biodiesel blends by experiments and a new theoretical model based on the finite-time thermodynamics (FTT). In recent years, biodiesel utilization in diesel engines has been popular due to depletion of petroleum-based diesel fuel. In this study, performance of a single cylinder, four-stroke, direct injection (DI) diesel engine fueled with diesel–biodiesel mixtures has been experimentally and theoretically investigated. The simulation results agree with the experimental data. After model validation, the effects of engine load and biodiesel percentage on engine performance have been parametrically investigated. The results showed that, effective power increases constantly, effective efficiency increases to a specified value and then starts to decrease with increasing engine load at constant biodiesel percentage and compression ratio. However, effective efficiency increases, effective power decreases to a certain value and then begins to increase with increasing biodiesel percentage at constant equivalence ratio and compression ratio.

The effects of engine design and operating parameters on the performance of a diesel engine fueled with diesel-biodiesel blends

This paper reports the effects of engine design and operating parameters such as stroke length, ratio of bore to stroke length, compression ratio, equivalence ratio, engine load, biodiesel percentage, friction coefficient, engine speed and mean piston speed on engine performance and energy losses by experiments and a theoretical model based on the finite-time thermodynamics. In this study, the performance of a single cylinder, four-stroke, direct injection diesel engine fueled with diesel-biodiesel mixtures has been experimentally and theoretically investigated. The simulation results agree with the experimental data. After model verification, parametrical studies have been conducted for various conditions. The results showed that the biodiesel percentage and the cycle pressure ratio affect positively the engine performance. The friction coefficient has negative influence on the engine performance. The effective efficiency decreases with the increasing of the engine load, stroke length, and engine speed but effective power increases with increasing them. The effective power always increases with the increasing mean piston speed. However, the effective efficiency decreases at the constant stroke length condition, as it increases at the constant engine speed condition. The effective power and the effective efficiency increase with increasing equivalence ratio to a specified value and then begin to decrease for constant bore/stroke length conditions. The effective efficiency increases with decreasing equivalence ratio as effective power has an optimum value for constant compression ratio condition. The effects of bore/stroke length change at different conditions. At the constant compression ratio condition, the engine performance increases with increasing ratio of bore to stroke length. They are the optimum values which provide the maximum effective efficiency and maximum effective power at the other conditions. This study also reports the energy losses as the ratio of fuel energy and they are classified as friction losses, incomplete combustion losses, heat transfer losses, and exhaust losses. They are defined with respect to compression ratio. With the increasing compression ratio, the friction losses are constant for constant cycle temperature ratio and equivalence ratio, whereas the incomplete combustion losses increase at a constant cycle temperature ratio condition and are constant at constant equivalence ratio condition. The heat transfer losses increase and the exhaust losses decrease for both the conditions. The presented model could be used to optimize the performance of diesel engines fueled with biodiesel and it can be developed for all kinds of engines running at different conditions with various fuels.