Engine Speed Research Articles

A Review on Investigation of Petrol and Ethanol Blend as fuel on Performance of Spark Ignition Engine

Abstract: Finding substitute fuels has been more popular in recent years as a response to escalating pollution levels and fuel shortages. The goal of this research is to find the ideal gasoline to ethanol ratio that will maximize engine performance and reduce emissions in spark ignition engines. In order to analyse the performance of different blending ratios, the research looks at metrics such carbon monoxide (CO) emissions, brake power (BP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE). Blends of gasoline and ethanol with a 15% ethanol content greatly increase engine thermal efficiency at higher engine speeds. E12 mixes of gasoline and ethanol boost engine braking power while lowering CO emissions and breakspecific fuel usage. Blends of gasoline with ten to fifteen percent ethanol present a possible substitute.

Determining occupational exposure to inhalable wood dust in motor manual felling and processing

ABSTRACT The occupational exposure to softwood and hardwood wood dust was determined during forestry work in timber stands. In the determination of inhalable wood dust, three tree species (Fagus sylvatica, Quercus sp. and Pinus brutia) and three chainsaw operating parameters were taken into account (in total six assessment indicators). The first operating parameter was the chainsaw operating under normal conditions (regular chain sharpening). The second and third operating parameters were improper chainsaw maintenance (irregular chain sharpening) and low throttling pressing (operating the chainsaw at low engine speeds), respectively. The determination of inhalable wood dust concentrations from the ambient air was performed using the Inhalable Organic Matter (IOM) sampler, manufactured by SKC Button Sampler (Dorset, United Kingdom). Out of a total of 108 concentration cases of inhalable wood dust, 44 (40.74%) showed concentrations greater than 3.00 mg·m−3, while in 10 (9.26%) cases, the dust concentration exceeded 5 mg·m−3. The eight-hour time-weighted average exposure to wood dust ranged from 0.99 mg·m−3 to 12.52 mg·m−3, with an average of 4.22 mg·m−3. The results indicated that the increase in wood dust concentration was dependent on improper chainsaw maintenance, while low throttling pressing reduces dust concentration levels. Additionally, an increase in wood dust concentration was observed in species with thick bark (Pinus brutia and Quercus petraea).

Suitability Study of Biofuel Blend for Light Commercial Vehicle Application under Real-World Transient Operating Conditions

<div>Driving schedule of every vehicle involves transient operation in the form of changing engine speed and load conditions, which are relatively unchanged during steady-state conditions. As well, the results from transient conditions are more likely to reflect the reality. So, the current research article is focused on analyzing the biofuel-like lemon peel oil (LPO) behavior under real-world transient conditions with fuel injection parameter MAP developed from steady-state experiments. At first, engine parameters and response MAPs are developed by using a response surface methodology (RSM)-based multi-objective optimization technique. Then, the vehicle model has been developed by incorporating real-world transient operating conditions. Finally, the developed injection parameters and response MAPs are embedded in the vehicle model to analyze the biofuel behavior under transient operating conditions. The results obtained for diesel-fueled light commercial vehicle (LCV) have shown better fuel economy than LPO biofuel with their developed fuel injection parameter MAP. The maximum BTE obtained was 29.7% for diesel and 29.5% for LPO at 2100 rpm and 20 Nm torque. The mean HC emissions were identified as 0.02046 g/km for diesel and 0.03488 g/km for LPO fuel over the modified Indian driving cycle (MIDC). Except for NOx emission, LPO biofuel exhibited diesel-like performance and emission characteristics under the MIDC.</div>

Combustion of gasoline with oxygen-containing and nano-additives: An experimental study, modeling, optimization, and analysis survey

BackgroundPollutants emitted from fuel combustion have become a global concern, prompting researchers to explore solutions like fuel formulation modification. MethodsThis study delved into enhancing gasoline fuel performance and octane number by incorporating varying proportions of 2-methyl-1-propanol, bioethanol, MTBE additives, tert‑butanol, and nanoparticles (ZnO, ZrO2, and CNT). These compositions underwent assessment at different engine loads and speeds. Vapor pressure, a fundamental property of gasoline that signifies its volatility, was examined. Despite the utilization of diverse additives and enhancers, their impact on vapor pressure was minimal at relatively low concentrations. Significant findingsAs a result, flash point, octane number, and engine performance were evaluated for the developed fuels. The findings unveiled improved engine performance coupled with reduced emissions. The octane number demonstrated enhancement, approaching gasoline's, while the combustion point remained similar. Notably, pollutant levels exhibited significant reduction.When comparing gasoline fuel at an engine speed of 1500 RPM and a throttle opening of 30 % with gasoline mixed with 2-methyl-1-propanol alcohol, MTBE, and zirconium dioxide under identical conditions, the results showed a reduction of 82.8 % in carbon monoxide emissions, carbon dioxide decreased by 54.05 %, unburnt hydrocarbons decreased approximately by 42.42 %, nitrogen oxides reduced by 22.97 %, engine power increased by 0.5 %, torque increased up to 164 %, and the octane number increased by 7.03 %.

Study on backfire characteristics of port fuel injection single-cylinder hydrogen internal combustion engine

Hydrogen energy is one of the most promising sources of carbon neutrality from well to wheel. Among various applications of hydrogen energy, hydrogen internal combustion engines serve as the critical technical pathway. Nevertheless, several challenges persist, primarily related to abnormal combustion resulting from excessive flame propagation velocity. Of these challenges, backfire emerges as the most recurrent and pressing issue to be resolved in the port fuel-injected hydrogen internal combustion engine (PFI-H2ICE). In order to delve into the characteristics and mechanisms of backfire, this study concentrates on a critical internal parameter, namely the start of injection (SOI), and comprehensively assesses the backfire occurrences under varying lambda and engine speed conditions. Experimental findings reveal that SOI encompasses one of the pivotal factors influencing backfire. Backfire predominantly arises within two ranges of SOI conditions: the region before −430 degCA ATDC (Zone I) and the stretch between −360 degCA ATDC and − 280 degCA ATDC (Zone II). In the process of employing EGR to depress the effects of backfire on subsequent tests, it was incidentally found that the Universal Exhaust Gas Oxygen Sensor (UEGO) installed on the intake manifold for executing EGR rate calculations acted as a hotspot (with temperatures exceeding 100 °C). This not only intensified the backfire strength and the scope in Zone I but also caused the most severe backfire events to occur after −270 degCA ATDC (in Zone III). Despite this, the EGR strategy still demonstrated a significant backfire suppression effect, only exhibiting almost no influence on backfire caused by hotspots within the intake manifold. With an escalation in engine speed, the intensity of backfire diminishes, and the range of backfire occurrence decreases accordingly. By exercising control over SOI within the operating range from -430degCA to -360degCA ATDC (Zone A), the risk of backfire can be dramatically reduced, thereby achieving nearly backfire-free operation. Detailed analysis of cylinder pressure indicates that backfire may also give rise to other abnormal combustions, such as misfire, pre-ignition, and knock, in subsequent cycles. Moreover, this effect amplifies in tandem with an increase in mixture concentration. A certain degree of mutual promotion among diverse abnormal combustions is also observed. This study furnishes the most direct and practical foundation for internal and external strategies in the realm of backfire control.

Experimental Investigation of Glycerol Derivatives and C1–C4 Alcohols as Gasoline Oxygenates

Certain oxygenated compounds, when blended with gasoline, have the ability to inhibit the occurrence and decrease the intensity of engine knock, helping improve engine efficiency. Although ethanol has had widespread use as an oxygenate, higher alcohols, such as butanol, exhibit superior properties in some respects. Besides alcohols, glycerol derivatives such as glycerol tert-butyl ether (GTBE), among others, also have the potential to be used as gasoline oxygenates. This work provides a direct comparison, performed on a modified Waukesha CFR engine, of C1–C4 alcohols and the glycerol derivatives GTBE, solketal, and triacetin, all blended with a gasoline surrogate in different concentrations. The tests focused on how these oxygenated compounds affected the knocking behavior of the fuel blends, since it directly impacts engine efficiency. The test matrices comprised spark-timing sweeps at two different compression ratios, at stoichiometric conditions and constant engine speed. The results showed that, in general, the C1–C4 alcohols and the glycerol derivatives were effective in decreasing knock intensity. n-Butanol and solketal were the noteworthy exceptions, due to their demonstrated inferior knock-inhibiting abilities. On the other hand, isopropanol, isobutanol, and GTBE performed particularly well, indicating their potential to be used as gasoline oxygenates for future engines, as alternatives to ethanol.

Knockout of Hsp70 Genes Modulates Age-Related Transcriptomic Changes in Leg Muscles and Reduces the Locomotion Speed and Lifespan of Drosophila melanogaster

Knockout of Hsp70 Genes Modulates Age-Related Transcriptomic Changes in Leg Muscles and Reduces the Locomotion Speed and Lifespan of Drosophila melanogaster

Investigate the effect of EGR stratergies on the HCCI engine's performance with N-heptane fuel injection

In this study, the effect of EGR strategies on the HCCI engine's performance is studied. A program was established to control the injection fuel and amount of exhaust gas recirculation on the HCCI engine. The results of the research show that when the EGR rate is greater than 30%, the engine operates stably according to the HCCI combustion characteristic at speeds lower than 2400 rpm. But when engine speeds are higher than 2400 rpm, the HCCI combustion characteristic is unstable; the torque and the indicator efficiency decrease rapidly. When the HCCI engine increases the EGR rate, the start of combustion is gradually later, the coefficient gradually decreases to close to the black smoke characteristic curve, the CO, HC, and CO2 emissions increase. The NOx emissions tend to increase when the EGR ratio increases from 0–25%, but the NOx decreases when the EGR rate is greater than 25%.

A Method for Evaluating the Spatial Layout of Fire Stations in Chemical Industrial Parks

The development of chemical industrial parks has resulted in the accumulation of a significant amount of hazardous substances, thereby increasing the demand for enhanced firefighting security, which directly relates to fire stations. This article presents a method for the layout evaluation of fire stations within chemical industrial parks. A practical technique for conducting fire risk assessments of each point to be rescued (PTBR) is proposed. The PTBRs are categorized according to their levels of fire risk. The required rescue time for each PTBR is determined based on the fire risk assessment. The estimated rescue times from each PTBR to each fire station are evaluated based on the actual road network and the speed of the fire engines. The adequacy of the fire stations is assessed through comparing the required and estimated rescue times. The working process of this method is illustrated using an engineering instance. The evaluation results of this engineering instance indicate its feasibility. This method takes into account the impact of irregular road paths and the influence of PTBR fire risks on the layouts of fire stations, which results in a more objective evaluation.

Study on Torsional Vibration Response Characteristics of Marine Propulsion Shafting

_ The paper establishes the lumped parameter vibration mathematical model of shafting and uses the system matrix method to calculate and analyze steady-state frequency domain vibration characteristics of the shaft system in the range of diesel engine speed. Then in order to further study the transient torsional vibration of the shaft system under the resonance speed point, the state space method and finite element analysis method were used to compare and analyze the transient time domain response characteristic curve of the shaft system; finally, the test data of the real ship was compared with the theoretical calculation results, which verified the correctness of the mathematical model and the theoretical calculation method. This study has certain theoretical significance for carrying out the design of low-noise and vibration of shaft systems and improving the safety of ship navigation. Keywords shafting torsional vibration; transient time domain; finite element method; vibration test

Biomechanical analysis of real‐time vibration exposure during mini combine harvester operation: A hybrid ANN–GA approach

AbstractThis research focuses on designing and evaluating ergonomic self‐propelled machinery seats to reduce whole‐body vibration (WBV) exposure among male and female agricultural workers. Subjects without musculoskeletal disorders were selected, and their anthropometric parameters were analyzed. An ergonomically refined seat, considering anthropometric dimensions and vibration reduction, was developed and tested. Vibration isolators using piezoelectric material enhanced operator comfort. In a laboratory experiment, real‐time one‐third octave band WBV data were collected using various seat types and engine speeds. At 1200 rpm, female operators experienced WBV levels between 3.42 and 13.40 m/s², while males ranged from 3.13 to 12.20 m/s². At 1600 rpm, females (T‐1) had WBV levels of 20.20–42.39 m/s², and males recorded 18.90–40.12 m/s². At 2000 rpm (T‐1), female operators WBV ranged from 246.71 to 303.45 m/s², and males from 248.10 to 300.13 m/s². At 2400 rpm (T‐1), female operators experienced WBV from 385.29 to 457.87 m/s², and males from 381.57 to 445.50 m/s². An integrated approach with artificial neural networks and genetic algorithms optimized machine operating parameters, resulting in minimum WBV levels. The highly accurate Multilayer Feed‐Forward Artificial Neural Network model (2‐10‐1) had a correlation (R) of 0.996 and a low mean‐squared error of 0.198. This research underscores the effectiveness of seat isolators in reducing vibrations and highlights the importance of considering both seat design and engine speed, especially concerning gender‐specific differences in vibration tolerance. It provides valuable insights for improving the comfort and safety of self‐propelled machinery operators in agriculture.

Experimental Investigation of Gaseous Emissions and Hydrocarbon Speciation for MF and MTHF Gasoline Blends in DISI Engine

Article Experimental Investigation of Gaseous Emissions and Hydrocarbon Speciation for MF and MTHF Gasoline Blends in DISI Engine Rafiu K. Olalere 1,2, Gengxin Zhang 1, and Hongming Xu 1,3, * 1 Department of Mechanical Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK 2 Department Mechanical Engineering, Lagos State University of Science and Technology, Ikorodu 02341, Nigeria 3 State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China * Correspondence: h.m.xu@bham.ac.uk     Received: 8 November 2023 Accepted: 25 March 2024 Published: 28 March 2024   Abstract: With the increasing shortage of fossil energy, the development of engines urgently requires alternative fuels. Gaseous emissions of a gasoline direct injection spark ignition engine fueled with blends of 2-methylfuran (MF 20% vol. and gasoline 80% vol.) and 2-methyltetrahydrofuran (MTHF 20% vol. and gasoline 80% vol.) were experimentally investigated using Gasmeth FTIR. Experiments were conducted at air-fuel ratio (λ = 1) and at engine speed of 1500 rpm using the fuels optimised spark timing. Effects of fuel injection sweeps (180–280 °CA BTDC) on the emission characteristics of blends were investigated at the intermediate load of 5.5 bar IMEP. Hydrocarbon emission (HC) for gasoline is about 41% and 16% higher compared to MF20 and MTHF20 respectively. Carbon monoxide emission for the fuels increases as the injection timing is retarded but the Nitrogen oxide (NOx) emissions was observed to reduce with the retarded injection timing. Both MF20 and MTHF20 recorded high NOx emissions compared to gasoline. The results indicated ethylene (25–26%) as the major component of the HC speciation in the fuels investigated. The unburnt furan samples for blend fuels were determined to be less than 3% of HC emissions, which could be considered a safe level for exposure.

Ecotoxicological evaluation of effluent from bovine slaughterhouses disinfected by peracetic acid (PAA) using the bioindicator Girardia tigrina

The evaluation of the ecotoxicological effects of the effluent after treatment with peracetic acid is relevant to help establish reference concentrations for the disinfection process and waste recovery. Therefore, the objective of this work was to evaluate the ecotoxicity of effluent from a bovine slaughterhouse treated with peracetic acid on Girardia tigrina. The toxicity bioassays for planaria were the acute test (LC50) and chronic assays: locomotion, regeneration, reproduction and fertility. The results showed that the effluent treated with peracetic acid showed less toxicity than the effluent without application of peracetic acid. The effluent after peracetic acid application showed a chronic toxic effect in the reduction of locomotor speed in all studied disinfectant concentrations (0.8, 1.6, 3.3 and 6.6 μg L−1 of peracetic acid) and a delay in the formation of G. tigrina photoreceptors at the concentration of 6.6 μg L−1 of peracetic acid. Peracetic acid concentrations of 0.8, 1.6 and 3.3 μg L−1 were not toxic for blastema regeneration, photoreceptor and auricle formation, fecundity and fertility. In addition, this study assists in defining doses of peracetic acid to be recommended in order to ensure the wastewater disinfection process without causing harm to aquatic organisms.

Analysis of In-cylinder Flow in a Small-Bore Spark-Ignition Engine Using Computational Fluid Dynamics Simulations and Zero-Dimensional-Based Modeling

Abstract The evolution of in-cylinder flow involves small and large-scale structures during the intake and compression strokes, significantly influencing the fuel-air mixing and combustion processes. Extensive research has been conducted to investigate the flow evolution in medium to large-sized engines using laser-based diagnostic methods, computational fluid dynamics (CFD) simulations, and zero-dimensional (0-D) based modeling. However, in the present study, we provide a detailed analysis of the evolution of flow fields in a small-bore spark ignition engine with a displacement volume of 110 cm3. This analysis employs a unique methodology where CFD simulation is performed and validated using measured particle image velocimetry (PIV) data. Subsequently, the validated CFD results are utilized to develop and validate a 0-D-based model as it is computationally more efficient. The validated CFD simulation and 0-D-based model are used to evaluate the quantified strength of the flow fields by calculating the tumble ratio and turbulent kinetic energy (TKE). The streamlines and velocity vectors of the flow fields obtained from CFD simulations are utilized to explain the evolution of these parameters during intake and compression strokes. The study is further extended to analyze the effect of engine speed on the evolution of flow fields. With an increase in engine speed, relatively higher values of tumble ratio and TKE at the end of the compression stroke are observed, which is expected to improve the fuel-air mixing and combustion efficiency.

Combustion characteristics optimization and thermal efficiency enhancement by stratified charge of hydrogen direct injection for argon power cycle hydrogen engine

Argon power cycle hydrogen engine is a novel approach to increasing the thermal efficiency of hydrogen engines while achieving zero CO2 emissions. This paper presents a combination of experiments and simulations used to examine the effects of hydrogen direct injection on the combustion characteristics and thermal efficiency of argon power cycle engines. The results of the study indicate that, in comparison to port hydrogen injection, hydrogen direct injection produces a delay of CA50 exceeding 12.36°CA at an engine speed of 1000 r/min. This delay optimizes combustion and diminishes knock intensity to below 0.1 MPa by creating a stratified mixture, which in turn decelerates the combustion rate. Through adjusting hydrogen direct injection timing and incorporating super lean combustion, a maximum gross indicated thermal efficiency of 53.72% is achieved. By optimizing the first injection timing, the second injection timing, and the second injection ratio, dual hydrogen direct injection can significantly suppress knock and increase thermal efficiency compared with original single hydrogen injection conditions.

Dopamine lesions alter the striatal encoding of single-limb gait.

The striatum serves an important role in motor control, and neurons in this area encode the body's initiation, cessation, and speed of locomotion. However, it remains unclear whether the same neurons also encode the step-by-step rhythmic motor patterns of individual limbs that characterize gait. By combining high-speed video tracking, electrophysiology, and optogenetic tagging, we found that a sizable population of both D1 and D2 receptor expressing medium spiny projection neurons (MSNs) were phase-locked to the gait cycle of individual limbs in mice. Healthy animals showed balanced limb phase-locking between D1 and D2 MSNs, while dopamine depletion led to stronger phase-locking in D2 MSNs. These findings indicate that striatal neurons represent gait on a single-limb and step basis, and suggest that elevated limb phase-locking of D2 MSNs may underlie some of the gait impairments associated with dopamine loss.

Dopamine lesions alter the striatal encoding of single-limb gait

The striatum serves an important role in motor control, and neurons in this area encode the body’s initiation, cessation, and speed of locomotion. However, it remains unclear whether the same neurons also encode the step-by-step rhythmic motor patterns of individual limbs that characterize gait. By combining high-speed video tracking, electrophysiology, and optogenetic tagging, we found that a sizable population of both D1 and D2 receptor expressing medium spiny projection neurons (MSNs) were phase-locked to the gait cycle of individual limbs in mice. Healthy animals showed balanced limb phase-locking between D1 and D2 MSNs, while dopamine depletion led to stronger phase-locking in D2 MSNs. These findings indicate that striatal neurons represent gait on a single-limb and step basis, and suggest that elevated limb phase-locking of D2 MSNs may underlie some of the gait impairments associated with dopamine loss.

A Review of Recent Advancements in Knock Detection in Spark Ignition Engines

In gasoline engines, the combustion process involves a flame’s propagation from the spark plug to the cylinder walls, resulting in the localized heating and pressurization of the cylinder content ahead of the flame, which can lead to the autoignition of the gasoline and air. The energy release from the autoignition event causes the engine cylinder to resonate, causing an unpleasant noise and eventual engine damage. This process is termed as knock. Avoiding knock has resulted in limiting the maximum engine pressures, and hence limiting the maximum efficiencies of the engine. Modern engines employ knock sensors to detect resonances, adjusting the spark plug timing to reduce pressures and temperatures, albeit at the expense of engine performance. This paper sets out to review the different signals that can be measured from an engine to detect the start of knock. These signals traditionally consist of the in-cylinder pressure, the vibrations of the engine block, and acoustic noise. This paper reviews each of these techniques, with a focus on recent advances. A number of novel methods are also presented, including identifying perturbations in the engine speed or exhaust temperature; measuring the ion charge across the spark plug leads; and using artificial intelligence to build models based on engine conditions. Each of these approaches is also reviewed and compared to the more traditional approaches. This review finds that in-cylinder pressure measurements remain as the most accurate for detecting knock in modern engines; however, their usage is limited to research settings. Meanwhile, new sensors and processing techniques for vibration measurements will more accurately detect knock in modern vehicles in the short term. Acoustic measurements and other novel approaches are showing promise in the long term.

Experimental optimization of displacer working gap in a gamma-type Stirling engine

In this experimental study, the effects of the working gap between the displacer and its cylinder on the performance of a gamma configuration Stirling engine were investigated. The torque and power variations with engine speed were investigated for four different working gap values as 0.5, 0.7, 0.9, and 1.1 mm. Experiments were carried out with an LPG-fueled heater at a hot surface temperature of 375 °C and a cold surface temperature of 30 °C. Helium was used as the working mass and the tests were performed between 0.5 and 3.5 bar initial pressure with 0.5 bar ranges. According to the experimental results, the gap width has a significant effect on the gap losses and heat transfer and directly affects the performance of the gamma Stirling engine. Therefore, optimizing the gap width is necessary if the Stirling engine's efficiency is to be increased. In this study, the optimum displacer gap value was obtained as 0.9 mm for 90 mm cylinder diameter and 190 mm displacer length of a gamma Stirling engine. Maximum output power and torque were obtained at 3 bar initial pressure and 0.9 mm displacer gap as 45.06 W at 260 rpm and 2.18 Nm at 170 rpm, respectively. This study made an essential contribution to the literature by performing an experimental gap width optimization.

Deep Learning Methods for Tracking the Locomotion of Individual Chickens.

Poultry locomotion is an important indicator of animal health, welfare, and productivity. Traditional methodologies such as manual observation or the use of wearable devices encounter significant challenges, including potential stress induction and behavioral alteration in animals. This research introduced an innovative approach that employs an enhanced track anything model (TAM) to track chickens in various experimental settings for locomotion analysis. Utilizing a dataset comprising both dyed and undyed broilers and layers, the TAM model was adapted and rigorously evaluated for its capability in non-intrusively tracking and analyzing poultry movement by intersection over union (mIoU) and the root mean square error (RMSE). The findings underscore TAM's superior segmentation and tracking capabilities, particularly its exemplary performance against other state-of-the-art models, such as YOLO (you only look once) models of YOLOv5 and YOLOv8, and its high mIoU values (93.12%) across diverse chicken categories. Moreover, the model demonstrated notable accuracy in speed detection, as evidenced by an RMSE value of 0.02 m/s, offering a technologically advanced, consistent, and non-intrusive method for tracking and estimating the locomotion speed of chickens. This research not only substantiates TAM as a potent tool for detailed poultry behavior analysis and monitoring but also illuminates its potential applicability in broader livestock monitoring scenarios, thereby contributing to the enhancement of animal welfare and management in poultry farming through automated, non-intrusive monitoring and analysis.