Influence Of Compression Ratio Research Articles

Effect of Piston Geometry on Performance Characteristics of VCR Engine with and without EGR when Fueled with Blends of Methyl Ester

The growing population and exhaustion of fossil fuels necessitate our search for new sources of energy. The study for this research encompasses an amalgamation of interest in alternative fuels, advanced engine technology such as variable compression ratio VCR, engine component modification, and a methodical approach to testing for assessing the effects on key performance of the engine. A 3.5 kW compression ignition (CI) engine was fueled with blends of behada, chicken fat, and turmeric oil methyl ester. Engine operating parameters, such as the compression ratio (CR), rate of exhaust gas recirculation (EGR), and piston top geometry, are optimized to maximize engine performance. CI engine was modified by changing the piston head (square and tangential groove top) for methyl ester diesel blend operations. In the study, diesel fuel is designated as B00 and methyl ester as B20. The influence of compression ratio (CR16 and CR18) with exhaust gas re-circulation (EGR 0% and EGR 10%) was evaluated. The key performance indicators: brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), brake-specific fuel consumption (BSFC), air-to-fuel ratio (AFR), and exhaust gas temperature (EGT) are investigated. Results indicate that an increase in BTE accompanies an increase in load, suggesting enhanced thermal efficiency with increased power output. The consequence of VCR is also investigated, and it is determined that a higher CR results in a higher BTE due to an increase in compression pressure and temperature, thereby enhancing combustion. Due to the re-combustion of unburned hydrocarbons with the addition of EGR at a 10% rate, BTE increases further. Utilizing a piston geometry with tangential grooves and methyl ester blends also contributes to increased BTE. BSEC increases with increasing load, with an important rise observed when operating at maximum capacity. However,at CR 18, BSEC decreases as a result of enhanced combustion efficiency. EGR has different effects on BSEC depending on the geometry of the piston and the kind of fuel used. Enhanced air-fuel blending and re-combustion of unburned hydrocarbons reduce the BSEC of the engine. The tangential groove top piston operates with 10% EGR. Similar to BSEC, BSFC decreases with increasing CR and improves with the use of a piston with a tangential groove and 10% EGR operation. AFR decreases as the consumption of fuel increases to meet the power demand, and higher CR values result in a lower AFR. EGT rises with load, and CR18 has a lower EGT than CR16 as a result of a higher compressing temperature and pressure. 10% EGR operation reduces EGT by decreasing the concentration of oxygen in the combustible area.

Influence of Compression Ratio on Pressure in the Cylinder of Internal Combustion Engine

Influence of Compression Ratio on Pressure in the Cylinder of Internal Combustion Engine

Influence of compression ratio on the performance characteristics of a spark ignition engine

In this study, the influence of the compression ratio on the performance characteristics of a gasoline engine was investigated in detail using COMSOL simulations. Four compression ratios — 8, 9, 10 and 11 — were investigated at different engine speeds between 1000 and 1800. The analysis focused on power output, braking performance and fuel consumption in order to decipher the complicated relationships between compression ratios and engine dynamics. The results showed a significant increase in power output with increasing compression ratio, highlighting the delicate balance required for optimal power generation. Braking power increased with higher compression ratios, indicating a potential improvement in braking performance. In addition, the study showed a correlation between increased fuel consumption and higher compression ratios, highlighting the need for strategic fuel-saving measures. These results contribute to the understanding of gasoline engine behavior and provide insights into the trade-offs that need to be made when adjusting the compression ratio. Recommendations include experimental validation, exploration of dynamic compression control, research into integrated braking systems, investigation of sustainable fuel strategies and a focus on multi-metric optimization. The observed increase in power output at higher compression ratios highlights an important aspect of engine optimization. Engineers and researchers need to carefully consider compression ratio adjustments to ensure optimal power generation while maintaining efficiency. This insight can guide the development of engines that strike an ideal balance between power and fuel efficiency.

Retracted: Study on the Influence of Compression Ratio on the Rail Contact Fatigue Resistance Property and Its Mechanism.

[This retracts the article DOI: 10.1155/2021/9057677.].

Experimental analysis on the influence of compression ratio, flow rate, injection pressure, and injection timing on the acetylene - diesel aspirated dual fuel engine.

The predicted scarcity, increasing cost of petroleum fuels, and environmental degradation are encouraging researchers to search for alternative fuels throughout the world. Hence, it is intended to utilize acetylene-based DF in the compression ignition (CI) engine with minor modifications. An engine of 5 Hp, four stroke, single-cylinder, water-cooled operated in dual-fuel (DF) mode (acetylene gas-diesel), aiming to reduce the emissions, was deployed to investigate its characteristics. In DF mode, gaseous fuel is injected through intake air manifold with 2, 4, and 6 lpm constantly. According to the research findings, the gas rate of 6 lpm provides the best results, having a superior BTE of 30.7%. Various compression ratios (16:1, 18:1, and 20:1) were used to determine the optimal compression ratio (CR) under a volume flow rate of 6 lpm with diesel. Fuel injector pressure (200, 220, and 240bar) with injector intervals (19°, 23°, and 27°bTDC) were changed consecutive sequence while adjusting CR, and the best outcomes for improved CI fuel efficiency were determined. From the investigational analysis, the peak in-cylinder pressure and net HRR (heat release rate) are assessed for being better by the increment in CR in DF mode of operation with an acetylene gas of 6 lpm at all operating settings. At a 240bar injection pressure, the BTE is recorded highest (35.1%), and smoke was decreased. An IT of 23obTDC, the CO and HC were found as to be minimum as 28ppm and 0.04ppm.

ANNONA OIL METHYL ESTER FUELLED-TURBOCHARGED DIESEL ENGINE: INFLUENCE OF COMPRESSION RATIO AND INJECTION TIMING UPON OVERALL EMISSION BEHAVIOR

ANNONA OIL METHYL ESTER FUELLED-TURBOCHARGED DIESEL ENGINE: INFLUENCE OF COMPRESSION RATIO AND INJECTION TIMING UPON OVERALL EMISSION BEHAVIOR

BIODIESEL FUELED TURBOCHARGED DIRECT-INJECTION ENGINE: INFLUENCE OF COMPRESSION RATIO ON ENGINE PERFORMANCE AND EMISSION CHARACTERISTICS

BIODIESEL FUELED TURBOCHARGED DIRECT-INJECTION ENGINE: INFLUENCE OF COMPRESSION RATIO ON ENGINE PERFORMANCE AND EMISSION CHARACTERISTICS

Study on the Influence of Compression Ratio on the Rail Contact Fatigue Resistance Property and Its Mechanism.

Contact fatigue resistance properties of four commercial steel rails were systematically studied and compared. The contact fatigue limit cycles, fracture toughness, and fatigue crack growth rate of the corresponding rails with different compression ratios were tested and analyzed, which showed a close relationship between them. Moreover, microstructures of the rails were carefully observed by using the TEM to elucidate the scientific mechanisms. Observations and obtained results indicated that pearlite lamellar spacing further decreased with the rise of compression ratio, which greatly and rightly contributed to the improved fatigue resistance property.

Simulation Research of the Influence of Compression Ratio on the Performance of an Aircraft Piston Diesel Engine

Simulation Research of the Influence of Compression Ratio on the Performance of an Aircraft Piston Diesel Engine

Effect of Shorea robusta methyl ester biodiesel blends on the exergy and sustainability analysis of diesel engine

ABSTRACT In this experimental investigation, the impact of engine load, compression ratio, and percentage blends of biofuel on exergy, energy, and sustainability parameters for the samples of diesel based (10–40% v/v) biodiesel blends were performed on variable compression ratio engine. The brake thermal efficiency, exergy efficiency, engine sustainability, exergy destruction rate, and other exergy parameters were found to escalate with the escalating engine load, compression ratio, and percentage of Shorea robusta methyl ester biodiesel fuel blends. The exergy and energy efficiency of the engine with diesel fuel were 2.05%, 6.98%, and 10.63%, respectively higher than 10%, 30%, and 40% Shorea robusta methyl ester fuel and 2.23%, 8.67%, and 9.22%, respectively at 50% engine load and 1500 rpm engine speed. The influence of compression ratio, engine load, and fuel blends on the exergetic performance parameters revealed a similar trend with energetic parameters, but the magnitude of exergy parameters was found lower than the energetic parameters. The application of Shorea robusta methyl ester biodiesel blends improved the combustion characteristics with a small drop in energy and exergy performance parameters and sustainability of the engine. The exergy destruction rate and entropy generation rate for shorea robusta methyl ester biodiesel blend were found lower than the conventional fuel. Therefore, the fuel blend have a high potential to be an alternate to the conventional fuel without any design modification of diesel engines.

Influence of Compression Ratio on Flywheel Dimension for a Naturally Aspirated Spark Ignition Engine: A Numerical Study

The proper design of the flywheel undeniably determines in tuning the engine to confirm the better output engine performance. The aim of this study is to mathematically investigate the effect of various values of the compression ratio on some essential parameters to determine the appropriate value for the flywheel dimension. A numerical calculation approach was proposed to eventually determine the dimension of the engine flywheel on a five-cylinder four-stroke Spark Ignition (SI) engine. The various compression ratios of 8.5, 9, 9.5, 10, 10.5, and 11 were selected to perform the calculations. The effects of compression ratio on effective pressure, indicated mean effective pressure (IMEP), dynamic irregularity value of the crankshaft, and the diameter of the flywheel was clearly investigated. The study found that 2.5 increment value of the compression ratio significantly increases the effective pressure of about 41.53% on the starting of the expansion stroke. While at the end of the compression stroke, the rise of effective pressure is about 76.67%, and the changes in dynamic irregularity merely increase by about 1.79%. The same trend applies to the flywheel diameter and width, which increases 2.08% for both.

Calculating Study of the Diesel Engine Working Process

A calculating study of the working process of the D-245 diesel engine (4 ChN 11/12,5) produced by the Minsk motor plant is carried out. The influence of compression ratio, fuel injection advance angle and gas distribution phases on the fuel efficiency indicators of the diesel engine under consideration is studied. The optimal values of the diesel engine parameters in various modes of operation are determined. Keywords internal combustion engine, diesel engine, fuel efficiency, compression ratio, fuel injection advance angle, gas distribution phases

Experimental investigations on the influence of compression ratio and piston crown geometry on the performance of biogas fuelled small spark ignition engine

The present research work is an attempt to develop a dedicated biogas fuelled SI engine technology from a 100 cc motor cycle. Such a small engine is coupled with alternator especially suitable in remote rural electrification which is still not connected to grid line or has a limited access. The experimental work presents the performance results of a small 98 cc, single-cylinder, four stroke cycle gasoline engine which is optimized to run on scrubbed biogas (CH4 93.8%) and raw biogas (CH4 56.6%) with successive modifications to the engine and its components. The work is carried out in stages to develop a dedicated biogas engine technology. The various aspects like piston crown geometry and compression ratio (CR), is investigated in this research work to evaluate the performances using biogas as fuel and comparing the same with gasoline is also made with the results obtained during experimental tests. The tests were conducted at 3000 rpm using three pistons having different crown geometries and cleavage on its crown. The selected three pistons enable to study the significance of CR (in the range of 6–9) and piston crown geometry to achieve the optimal configuration. The experimental results have revealed that increase in CR in a close range of 8:1 with larger cleavage on piston crown geometry enhances engine performance for Biogas fuelled small S.I. engine 100 cc category. It has been observed during comparative analysis that the maximum power produced by the biogas fuelled engine has improved by 13.4%, BSEC has increased by 23.30% and there is an 18.18% improvement in BSFC.

Mechanical behavior and sealing performance of metal sealing system in roller cone bits

Metal sealing system is used frequently in the dynamic rotary seal of downhole tools of petroleum, natural gas and mining. Mechanical behavior and sealing performance of the metal sealing system in roller cone bit were analyzed in this paper. Influences of pressure difference, compression ratio, fluid pressure, angle and thermal load on the metal sealing system’s mechanical behavior and seal performance were studied. The results show that the effect of pressure difference should be considered under fluid pressure. The von Mises stress concentrates on the inside of O-rings under the influence of compression ratio. The low-stress area appears on the inside of O-rings under the effect of fluid pressure. The high-stress concentration area of metal sealing surface appears on the surface of metal rings under different angles. Sealing performance, compression ratio, fluid pressure and angle have the same change trend. Thermal load is not a single impact on the stress distribution and deformation, but together with fluid pressure affects the sealing performance. The dynamic O-ring more easily fails than the static O-ring. Those results can provide a new direction for the structural optimization of metal sealing system in roller cone bits.

Experimental Investigation into the Influence of Compression Ratio on Operating Characteristics of Single Cylinder CNG Engine with Port Injection

This paper indicates the early experimental results of a Ricardo model CNG engine R&D activity in Vietnam, the experiments were mainly focused on the effects of compression ratio on operating parameters of the tested single cylinder CNG engine particularly designed and fabricated for varying compression ratio purpose. The compression ratio was set in the range of ε = 10 to 15 with the change step of Δε = 1. For each compression ratio, the engine speed were varried from 1000rpm to 2200rpm with the change step of Δn = 200. The early spark angle was also changed to find out the maximum break torque. The limitation of compression ratio and engine speed at each operating point was determined by vibration signal and abnormal sound. The experimental results indicated the early spark angle must be adjusted premature in case of compression ratio and/or engine speed enhenced. Especially, the portion of indispensable power to perform the compression stroke is smaller in comparison with the portion to execute the both strokes of intake and exhaust. In addition, the shape of combustion chamber affected strongly the operating characteristics also found in this study.

Experimental exploration of the impact of compression ratio on the characteristics of a biogas fueled dual fuel compression ignition engine

The influence of compression ratio on the characteristics of combustion, emission and performance in a dual fuelled CI engine using bio gas as the pilot fuel have been explored. The experiments were executed at four different CRs, viz. 16.5, 17, 17.5 and 18 under four distinct load settings of engine, viz. 25%, 50%, 75% and 100% respectively. The results from the investigation manifested an overall superior characteristics of combustion, emissions and performance at CR = 18 as compared to the other values. In contrast to the diesel only approach, the dual fuel approach resulted in superior improvement in NO x emissions for all the load settings.

Numerical Investigation of Injection Timing Influence on Fuel Slip and Influence of Compression Ratio on Knock Occurrence in Conventional Dual Fuel Engine

Numerical Investigation of Injection Timing Influence on Fuel Slip and Influence of Compression Ratio on Knock Occurrence in Conventional Dual Fuel Engine

Thermodynamic performance of Dual-Miller cycle (DMC) with polytropic processes based on power output, thermal efficiency and ecological function

This study reports a new model of an air standard Dual-Miller cycle (DMC) with two polytropic processes and heat transfer loss. The two reversible adiabatic processes which could not be realized in practice are replaced with two polytropic processes in order to more accurately reflect the practical working performance. The heat transfer loss is taken into account. The expressions of power output, thermal efficiency, entropy generation rate (EGR) and ecological function are addressed using finite-time thermodynamic theory. Through numerical calculations, the influences of compression ratio, cut-off ratio and polytropic exponent on the performance are thermodynamically analyzed. The model can be simplified to other cycle models under specific conditions, which means the results have an certain universality and may be helpful in the design of practical heat engines. It is shown that the entropy generation minimization does not always lead to the best system performance.

The improved model of inter-particle breakage considering the transformation of particle shape for cone crusher

To describe the essence of the inter-particle breakage behavior of the granular materials in the cone crusher accurately, an improved model is established based on the inter-particle breakage theory and population balance theory. In this model, a relative particle size ratio is introduced for describing the breakage characteristics of particles with different size, and the transformation of particle shape is considered in the inter-particle breakage.According to the standards of BS 812 part 105, the cubic and flaky particles are selected as breakage materials of inter-particle breakage experiment. Based on the experimental data, the influence of compression ratio, particle size distribution ratio and relative particle size ratio on the inter-particle breakage is investigated, the particle shape transformation function of polynomial form is built, and then the improved inter-particle breakage model considering the transformation of particle shape is established. Thus, the dynamic process of inter-particles breakage with two kinds of particle shapes in the cone crusher is simulated, and the flakiness index of cone crusher product can be calculated theoretically.A full-scale test with ZS200MF cone crusher was conducted in Tangshan, China. The particle size distribution and particle shape component of the crushing product were investigated by simulation with the improved model. Through the comparison of the measurement and the simulation, the maximum error of cumulated weight distribution is 4.8%, and the maximum error of flakiness index is 4.6%, then the effectiveness and practicability of this model are proved. Thus, the improved model can predict the quality of crushing product by utilizing the granular property of feed, the geometry of crushing chamber and operational parameters of cone crusher, which provides a theoretical foundation for product quality improvement, high-energy crushing chamber design and operational parameters optimization of cone crusher.

Effect of compression ratio and hydrogen addition on part throttle performance of a LPG fuelled lean burn spark ignition engine

A single cylinder CI engine was modified to operate as a LPG fuelled lean burn SI engine. The engine was tested at 1500rpm and 20% throttle opening at compression ratios 9:1, 10:1, 10.5:1 and 11:1 by varying equivalence ratios. The influence of compression ratio and 15% hydrogen substitution on energy basis at the optimal compression ratio of 10.5:1 on performance, emission and combustion behavior were studied and compared. The brake thermal efficiency and brake power output increases with rise in compression ratio, and above a critical value of 10.5:1 the improvement was small when compared to the increase in emissions. The advantage of brake thermal efficiency from higher compression ratio is narrow under low load conditions. The ever increasing load due to the auxiliaries which are likely to grow more require better low load performance and emissions. Wide flammable limits of hydrogen enable ultra-lean combustion and its anti-knock enhancement makes it advantageous compared to increasing the compression ratio at part throttle condition. Hydrogen addition enhanced the combustion rate and heat release rate, reduced cyclic variations, and extended the lean limit of operation. There was perceptible improvement in brake thermal efficiency, brake power and considerable reductions in hydrocarbon, carbon monoxide and carbon dioxide levels. Due to retarded ignition timing the NOx emission increase was not significant.