Variable Compression Ratio Engine Research Articles

An insight into the combustion analysis of low carbon alcohol infused ternary fuel blends operated by varying the compression ratios

To address the growing scarcity and rising costs of fossil fuels, researchers are exploring alternative energy sources that can mimic the conventional fuels. This study focused on ternary fuel blends made from waste fried oil (WFO) biodiesel, methanol, and diesel. To enhance their stability, 10, 20, and 30 ml of n-butanol per litre of ternary blends are added. The blends were tested in a variable compression ratio (VCR) engine under peak load conditions. The experiments are carried out by varying the compression ratio (CR) of the engine from 16:1 to 18:1. The results showed that increasing the CR improved combustion for all fuel blends. Among the ternary blends, B30M20D50 outperformed pure diesel in terms of combustion characteristics. When compared to diesel, B30M20D50 yielded 5.08 %, 5.31 %, and 4.59 % higher Pmax at CR 16:1, 17:1, and 18:1, respectively. Under the same conditions, NHRR outperformed diesel by 1.46 %, 3.12 %, and 2.44 %, respectively. While ternary blends with up to 20 % methanol exhibited stable combustion, higher methanol concentrations led to erratic rise in the coefficient of variation. The interdependency analysis revealed a strong correlation between the combustion parameters for the B20M30D50 blend across different compression ratios.

Investigation on NOx control of a CI engine through the collective effect of hydrogen and biodiesel blend at modified compression ratio

The main challenges with using biodiesel in CI engines are higher NOx emissions and reduced brake thermal efficiency. These biodiesel-related issues can be handled by concurrently introducing gaseous fuels along with primary fuel into CI engines. This study examines the effects of hydrogen in a dual fuel mode operation with diesel and Calophyllum inophyllum biodiesel blend (B20) at different compression ratios on the engine's performance, combustion, and emission characteristics. A single-cylinder, 4-stroke, variable compression ratio engine operating at 1500 rpm was used for the research. A standard compression ratio (SCR) of 17.5 and a modified compression ratio (MCR) of 15.5 at a constant hydrogen flow rate of 6 L per minute (lpm) were used with diesel and B 20. The addition of hydrogen with diesel and B20 resulted in higher cylinder pressure and heat release rate when compared to pure diesel and B20 operation. This resulted in a shorter delay period (by an average of 9.4 % and 7.1 %) with lower peak pressure than pure diesel and B20 operation. During the dual fuel mode of H2 with B 20 at a modified compression ratio, the maximum heat release rate was decreased and its occurrence was retarded. NOx, UBHC, and CO emissions of the engine were decreased significantly by an average of 20.8% 43.7, %, and 22 % respectively with 37.7 % increase in smoke opacity. The increase in NOx emission with the use of H2 with diesel was reduced by operating H2 with B20 and at a reduced compression ratio. This lower emission was achieved with a compromise of a marginal decrease in engine brake thermal efficiency.

Evaluation of Aluminum Oxide Nanoparticle Blended with Alcohol Based Biodiesel at Variable Compression Ratios

This paper highlights the use of aluminum oxide nanoparticles as an additive in diesel-butanol blends to show its effect on fuel consumption, emissions and performance. In the present experiment, different concentrations of aluminium oxide nanoadditives (30, 50, and 70 ppm) are used in alcohol-based biodiesel. Butanol has been used in concentrations of 5 and 10 % in diesel and therefore all blends are termed as B5 and B10 in addition to nanoparticle concentration to avoid complexity. These different blends (B5+30, B5+50, B5+70, B10+30, B10+50, B10+70) are tested for various engine loads at a constant speed of 1500 rpm. The experiment was performed on a Variable compression ratio (VCR) engine at varying compression ratios of 16, 17, and 18. Engine characteristics at different compositions of the blend at different compression ratios were provided by the interfaced computer through the software. The enhanced performance effects can be easily seen from the outcomes in the increment in brake thermal efficiency of the blends as compared to neat diesel. Considerable decrement can be observed in carbon monoxide (CO) and unburnt hydrocarbon (HC) values with an increase in compression ratio. Moderate reduction can be observed in NOx at higher loads in contrast to neat diesel.

Innovative Solutions for Clean Transportation: Variable Compression Ratio Engine Performance using Algae Biodiesel

Innovative Solutions for Clean Transportation: Variable Compression Ratio Engine Performance using Algae Biodiesel

The influence of injection pressure and exhaust gas recirculation on a VCR engine fueled by microalgae biodiesel

AbstractBiodiesel has been chosen as a decent alternative to diesel in the context of establishing environmentally pleasant conditions and saving petroleum‐based resources for future generations. It is well‐established that biodiesel‐powered diesel engines may achieve outcomes equivalent to those of diesel engines. The current investigation was conducted to study the effect of injection pressure (190, 210, and 230 bar) and exhaust gas recirculation (EGR) (5%, 10%, and 15%) on a single‐cylinder variable compression ratio (VCR) diesel engine running using a B20 (20% MB + 80% PD) blend of microalgae biodiesel (MABD). This experiment was conducted in two stages. During the first stage of experimentation, the efficiency and emission characteristics of a diesel engine with a B20 blend of MABD at various fuel injection pressures and fresh air were investigated. During the second phase, fresh air was mixed with 5%, 10%, and 15% exhaust gases, and the experiment was conducted. It was discovered that increasing injection pressure to 230 bar provided considerable improvements. Brake thermal efficiency increased by 2.35%, brake‐specific fuel consumption decreased by 3.57% and pollutants such as carbon monoxide (CO), hydrocarbon, and smoke were reduced by more than 50% compared to conventional diesel. These reductions were similarly significant (over 22%) as compared to the B20 blend at lower injection pressure (210 bar). However, there was a slight trade‐off: nitrogen oxide (NOx) emissions increased partially (3.14%), while exhaust gas temperature (EGT) increased by 1.72% at a higher pressure. The study then investigated the influence of EGR (5%, 10%, and 15%) at various injection pressures. The optimal value seems to be 10% EGR at 230 bar injection pressure. This combination substantially reduced NOx emissions (by over 41% compared to the normal B20 blend) and EGT (by more than 8%), while having no notable effect on other performance or emission variables. Overall, the results show that employing a B20 MABD blend with high injection pressure (230 bar) and moderate EGR (10%) improves engine performance while reducing hazardous emissions.

Machine learning-based modeling of variable compression ratio engine performance and emissions with JME-ZnO nanoemulsion

ABSTRACT Diesel engines fueled with nanoemulsion of biodiesel and diesel have shown promising results in reducing emissions without significant engine problems. However, the evaluation of the impact of biodiesel-nano emulsion on engine performance and exhaust emissions requires time-consuming and costly experimental testing. Modelling simulations have gained attention as a useful approach to overcome these challenges. Artificial intelligence (AI) has an extensive variety of applications in various domains, including energy systems. By training computers using machine learning (ML), they can make better decisions and outperform humans. AI-based models offer promising prospects in energy generation predictions. However, these prediction models can be computationally demanding. In this paper, the authors propose a Boosting-based Multi-Target Regression model using ML techniques to predict the pursuance and exhaust of a diesel engine. The study aims to advance the understanding of enhanced engine performance through the application of ML models. The MTXGB model demonstrates high average accuracy (high R2-score of 0.9989) and low error rates of 0.0123 for all six targets.

Experimental investigation of performance, emission, and combustion characteristics of a variable compression ratio engine using waste cooking vegetable oils blended with diesel

The availability of crude oil and petroleum products has become scarce and costly over the years leading to a stiff rise in engine fuel. Due to the depletion of conventional fuels; alternative fuels are gaining importance in recent times and Waste Cooking Vegetable Oils (WCVOs) are the viable option for the same. The present study highlights the performance, emission, and combustion characteristics of the Variable Compression Ratio (VCR) engine using three varieties of WCVOs (Ground Nut (GDN), Palm (PM), and Sunflower (SF)). Their inferior fuel features (density, viscosity, calorific value, etc.) are enhanced by blending 30 % of these oils with 70 % Diesel. The experiments are then conducted in the VCR engine using these blended oils under varying loading conditions (0–8 N) and at a constant speed of 1500 (RPM) with a compression ratio (18:1). It is seen that a single blend of Palm oil (PM) increases the engine Brake Thermal Efficiency (BTE) by 5 % in comparison to Diesel and other blended fuels (GDN, SF) owing to its lower calorific value and greater viscosity. The engine Brake Specific Fuel Consumption (BSFC) decreases with the increase in load and the lower loads reduce the BSFC for WCVOs by 9–15 % compared to Diesel. Engine emissions like Carbon Monoxide (CO), Nitrogen Oxide (NOx), and Hydrocarbons (HC) are also reduced significantly (by 12–15 %) using these blended oils compared to Diesel. The surge in both the Peak Cylinder Pressure (PCP) and Heat Release Rate (HRR) is also observed using these blended fuels, especially for Sunflower. Hence, these WCVOs are an appropriate option to advance the VCR engine performance and decrease its emissions.

Performance and emission analysis of Karanja biodiesel using variable compression ratio engine

Performance and emission analysis of Karanja biodiesel using variable compression ratio engine

Alumina and titanium nanoparticles to diesel–Guizotia abyssinica (L.) biodiesel blends on MFVCR engine performance and emissions

Deteriorating air quality and diminishing fossil fuel reserves drive the demand for alternative fuels. Biodiesel from animal and plant sources appears promising, but it has drawbacks like lower thermal efficiency and higher fuel consumption. One solution is exploring Nano additive biodiesel for internal combustion engines to address these limitations. The present research focuses on Guizotia abyssinica (L.) (GA) crops and the synthesis of biofuels from the bioresource and the aluminium oxide (Al2O3) and titanium dioxide (TiO2) nanoparticles. During nanoparticle characterization in X-ray diffraction (XRD), the interplanar spacing for the most intense peaks of (222) and (101) in Al2O3 and TiO2 was observed to be 2.63 and 3.48, respectively. Scanning Electron Microscopy (SEM) confirmed the formation of Al2O3 and TiO2. In the experimental evaluation, a multi-fuel variable compression ratio (MFVCR) engine was used to evaluate the performance and TESTO350 for the emission analysis. Nano additive biodiesel achieved a peak cylinder pressure of 55.19 bar and reduced CO emissions by 9.78 % compared to other biodiesel blends. The inclusion of nano additives in biodiesel resulted in a maximum brake thermal efficiency of 32.99 % and a minimum brake-specific fuel consumption of 0.362 kg/kWh compared to other fuels in the study.

The effect of 1-octanol blending on the multi-stage autoignition of conventional diesel and HVO fuels

Alternative fuels can reduce the carbon intensity of diesel engine use, and a detailed understanding of the combustion process for these fuels can minimize resulting fuel consumption and emissions. 1-Octanol has been considered as an alternative diesel fuel, but little work evaluating its combustion process in detail exists. In this work, ignition of 1-octanol, both pure and in blends with conventional and renewable diesel base fuels, is analyzed in a constant volume combustion chamber and a modified Cooperative Fuels Research Octane Rating engine operating in homogeneous charge compression ignition combustion mode. 1-Octanol blending reduced the derived cetane number of either base fuel, but modest increases in chamber temperature at injection could compensate for even dramatic reductions in derived cetane number. It was further found that greater amounts of low-temperature heat release were required to reach main ignition as the 1-octanol blending volume fraction was increased in the constant volume combustion chamber. This finding is attributed to the changing local equivalence ratio, as the reacting spray diffuses further into the chamber and approaches the (lean) global equivalence ratio as the ignition delay grows. Finally, it was found that, despite lowering the derived cetane number, 1-octanol blending enhanced the reactivity of the conventional diesel fuel observed in the variable compression ratio engine. This finding is attributed to the higher rates of hydrogen abstraction from the weaker average C–H bonds in 1-octanol, as hydrogen abstraction governs intermediate temperature heat release. These findings clarify the effect of 1-octanol on physical processes and the various chemical regimes of heat release in compression ignition. The dependence of the effects of 1-octanol blending on the base fuel are emphasized, as these can inform the deployment of 1-octanol as a diesel blendstock. Application of these results can support the optimization of conventional combustion strategies for use with 1-octanol, as well as the development of 1-octanol-fueled low-temperature combustion strategies with the associated promise of very low criteria pollutant emissions.

Energy and exergy analysis of VCR engine fueled with rubber-seed oil methyl ester using response surface methodology

This study presents a comprehensive analysis of the thermodynamic performance of a variable compression ratio engine fueled with rubber-seed oil methyl ester blended with diesel. The objective is to evaluate the energy and exergy characteristics according to the first and second laws of thermodynamics for various compression ratios and supercharging pressures. A 3.5 kW engine with compression ratios values ranging from 18:1 to 22:1 and SC pressures of 0, 0.25, and 0.5 bar (g) at 80% load was considered. The inlet manifold pressure was controlled using a centrifugal-type blower (1.5 m3/min, 350 W, 240 V AC) with an adjustable valve. Key fuel energy parameters including shaft energy, cylinder pressure, brake specific energy consumption, thermal efficiency, heat release rate, absorbed energy by cooling water, exhaust gas temperature, exergy efficiency, exergy destruction, exhaust energy, and emissions were analyzed. Results showed significant improvements in shaft energy (35.51%), thermal efficiency (35.37%), and heat release rate (25.17 J/°CA) for compression ratios 20 and supercharging pressure of 0.25 bar, with a reduction in brake specific energy consumption of 2.912 kJ/s kW. The second law efficiency and irreversibility were observed to be 60.31% and 0.0118 kW/K, respectively. Experimental findings demonstrated a reduction in carbon monoxide (25.12%) and hydrocarbon (40%) under the aforementioned conditions. Response surface methodology was employed to predict optimal operating conditions, and the equations were validated using analysis of variance and p-test. The D-optimality test facilitated the determination of optimal operating parameters for different responses through multi-objective optimization techniques. Individual desirability values were combined to obtain a composite desirability of 0.9054. The study identified compression ratios 18 with a supercharging pressure of 1.78 bar as the optimum operating condition for 20% fuel blends in a low-speed agricultural diesel engine, resulting in a remarkable improvement of 41.24% in energy efficiency and 68.45% in exergy efficiency, with minimal emissions.

Impact of Diethyl Ether on Performance and Emission Characteristics of a VCR Diesel Engine Fueled by Dual Biodiesel

Biodiesel is widely known as the alternative fuel for the diesel engine, but it comes with its fair share of challenges. To minimize the pertinent drawbacks, fuel additives become an essential tool and help improve renewable fuel’s properties. In this current research, biodiesel is obtained from rice bran oil and cotton seed oil, with diethyl ether as an additive. Diethyl ether is known for good oxygen content, high cetane number, and low viscosity. Experiments were performed on a variable compression ratio engine at a compression ratio of 18:1, and the injection pressure (170 bar, 180 bar, 190 bar and 200 bar) and the injection timing (20, 21, 22 and 23°bTDC) with four different dual biodiesel blends (5%, 10%, 15% and 20% by volume). Different ratios of 1%, 2.5% and 5% of diethyl ether with biodiesel combination were examined in a single-cylinder, four-stroke diesel engine. The engine emission and performance features were discussed at different loads and constant engine speeds. It was observed that using 5% of diethyl ether with biodiesel blends improved brake thermal efficiency, brake-specific fuel consumption and decreased carbon dioxide and oxides of nitrogen emissions. The reduction of oxides of nitrogen emission contributes to biodiesel’s acceptability for the environment’s benefit. This investigation found that diethyl ether, along with dual biodiesel blends, has a better viability in diesel engines.

Performance and emission characteristics of Waste cooking oil biodiesel blended with nano additives on single cylinder diesel engine

In this paper, used cooking oil was investigated as a possible source of biofuel and blending with nano particles which increases the efficiency of biofuel, reduces the emissions, and ensures that the fuel burns completely. The (CeO2) cerium oxide and (MgO) magnesium oxide nano particles are blended with WCO using magnetic stirrer and ultrasonicator. The test being conducted using the sequence of fuel blends: 80% of diesel and 20% of WCO biofuel and 30 ppm Cerium oxide, 90% of diesel and 10% of WCO biofuel and 45 ppm of Cerium oxide, 80% of diesel and 20% of WCO biofuel and 30 ppm magnesium oxide, 90% of Diesel and 10% of WCO biofuel and 45 ppm magnesium oxide and testing its properties which include density, Kinematic Viscosity, Flash and fire point, Calorific value and using a variable compression ratio (VCR) engine, we test its BP, BTHE, SFC, and emissions characteristics such as NOx, CO, HC, CO2, and O2. Evaluating different blends and determining which one is a renewable alternative fuel by comparing their characteristics. Overall analysis shows that the B10CeO2 blend and B20CeO2 blend produces lower density, lowest kinematic viscosity, the highest flash and fire point and highest calorific value and B20CeO2 blend is more efficient than other biofuel blends. It gives higher BTHE and lower SFC. It also produces less HC, NOx, CO2 emission and high O2. That concludes B20CeO2 45 PPM blend indicating that the use of blended WCOB has the potential to be a more environmentally friendly alternative fuel.

Comparative Assessment of Low-Concentration Ethanol and Waste Fish Oil Biodiesel Blends on Emission Reduction and Performance Improvement in Variable Compression Ratio Engine

Comparative Assessment of Low-Concentration Ethanol and Waste Fish Oil Biodiesel Blends on Emission Reduction and Performance Improvement in Variable Compression Ratio Engine

Performance, Emission and Heat Transfer Optimisation of Variable Compression Ratio Engine Fuelled with Ricinus communis Biodiesel by Taguchi-Gray Rational Approach

Performance, Emission and Heat Transfer Optimisation of Variable Compression Ratio Engine Fuelled with Ricinus communis Biodiesel by Taguchi-Gray Rational Approach

Study on Performance and Emission Characteristics of CI Diesel Engine by adding liquid additives with Dual Fuel

For an extensive stretch of time, diesel motors have turned into the world’s “Central player” of transportation. However, fuel consumption, late natural concerns, and accordingly consistently expanding fuel costs have made the quest for another fuel basic. Scientists have shown an enormous interest in testing different plant and vegetable oils as an enhancement for diesel. This foundation Nox discharge is conveyed during the ignition of energizes at high temperatures. Inordinate NOx discharge has a scope of consequences for human wellbeing and the environment. In this article, we will talk about elective energy sources in contrast with petroleum derivatives utilizing the ASTM standard. Thus, in this specific occasion, we’re subbing waste cooking oil and Juliflora oil for nano-added substances like magnesium oxide (MgO) and ferrofluid (Fe3O4). The two oils are mixed in the accompanying rates: 10%, 20%, 30%, and 40%. The SBU Variable Compression Ratio Engine was utilized to execution examination, burning, and outflow attributes. Therefore, we can see a diminishing in HC, a break in warm execution, and an increment in NOx.

Performance analysis of vibration characteristics on VCR engine using hybrid honeycomb structure

There are a number of techniques available to reduce the engine vibration, and vibration isolation is one among those techniques. Such vibrations can be isolated using hybrid engine mounts that absorb the forces caused by vibration. Consequently, the present work proposes a hybrid aluminium mount filled with silica gel to isolate the engine vibration. Experiments were carried out on the variable compression ratio engine mounted on the hybrid honeycomb structure, and the free, forced vibrations, and frequency domains were analysed. The test results portrayed that the performance of the engine with a hybrid mount is found to be better than the conventional rubber mount. The hybrid sandwich panel with a honeycomb structure crowded with silica gel as fibrous material was utilized to isolate the engine vibrations. Compared with conventional mount (1.502 m/s2), high amount of vibration was reduced by honeycomb structured mount (0.814 m/s2) using different load conditions and fuel input pressure of 150 bar. Vibration in conventional mount for blower closing condition was 1.546 m/s2 and that in honeycomb structured mount was 1.4 m/s2.

Performance, Emission and Combustion Characteristics of a VCR Engine Fueled with Sea Mango Biodiesel/Diesel Blends

The constant emission of greenhouse gases into the atmosphere, due to the continuous burning of fossil fuels, has been driving researchers to develop an environmentally friendly alternative fuel solution. An experimental investigation was conducted on a laboratory scale, to evaluate the physicochemical qualities, performance, emissions, and combustion characteristics of sea mango oil biodiesel blends and pure diesel fuel on a single-cylinder, variable compression ratio (VCR) engine. Tests were conducted at 1500 rpm, 210 bar, and 23° bTDC, under varying loading circumstances of 0, 3, 6, 9, and 12 kgs, and compression ratios 16:1, 17:1, and 18:1, respectively. The findings revealed that higher compression ratios (CRs) improve the performance, emission, and combustion characteristics of an engine. At CR 18:1, BTHE, SFC, and EGT improved by 8.78%, 11.18%, and 2.52% more than the standard compression ratio (17:1). The CO, HC, and smoke emissions also lowered by 14.65%, 18.56%, and 11.56%, respectively, at CR 18:1. The NOx emissions increased by 6.77%. The combustion characteristics also improved, with an increase in the CR. The findings of this investigation show that sea mango biodiesel blends can be used as a diesel alternative at CR 18:1, with no engine modifications.

Influence of Varying Compression Ratio of a Compression Ignition Engine Fueled with B20 Blends of Sea Mango Biodiesel

The ever-worsening environmental situation brought on by the huge use of fossil fuels has ramped up biodiesel production. Several studies have shown that a 20% biodiesel-diesel blend (B20) could be the best for utility in a compression ignition (CI) engine. The present study focuses on the characteristics of a variable compression ratio (VCR) engine running with a B20 blend of sea mango biodiesel at compression ratios of 16:1, 17:1 and 18:1. VCR is a technology which permits the engine to modify its compression ratio to improve the fuel economy under varying loads. The experimental results reveal an improvement of 5.27% and 6.25% in the BTE as well as SFC with B20 mix, respectively, at compression ratio (CR) 18:1 against diesel at standard CR, which is 17:1. At CR 18:1, the CO, HC and smoke emissions of B20 fuel at full load were 26.78%, 37.76% and 23.44%, correspondingly lower than those of diesel at standard CR. However, the blend was found to have higher NOx emissions at all the CRs. The least NOx emissions of the blend were noted to be at CR 16:1, although it was 0.77% higher than diesel at standard CR. The combustion characteristics also improved at higher CRs. The findings of this study indicate that the B20 blend of sea mango biodiesel could be utilized at CR 18:1 to replace diesel without any engine modifications.

Erratum to “A novel investigation in the performance, combustion and emission characteristic of variable compression ratio engine using bio-diesel blends”

Erratum to “A novel investigation in the performance, combustion and emission characteristic of variable compression ratio engine using bio-diesel blends”