Engine Conditions Research Articles

Waste bull bone based reusable and biodegradable heterogeneous catalyst for alternate fuel production from WCO, and investigation of its usability as fuel substitute

Fast-growing fuel demand by an increase in diesel vehicles and diesel engine applications for various sectors motivates researchers to develop alternate fuels. Though many approaches have been proposed, this investigation is unique by producing alternate fuels from the waste cooking oil (WCO) using a biodegradable, reusable, easy-to-handle, eco-friendly, and heterogeneous catalyst developed to form the waste bull bone and characterized for alternate fuel production from WCO. The zero-waste approach, eco-friendly fuel blends, and low-cost production factors were considered. The preprocessing of WCO was carried out by the bubble washes method, followed by transesterification processing for producing biofuel. The fuel blends were tested with different ratios like 20% to 80% with diesel and short out B20 grade. Further, the blends were prepared with Diethyl ether (DEE) and Ethanol. Total eight fuels (Diesel, B20, B20 + 5 wt% DEE, B20 + 10 wt% DEE, B20 + 5 wt% Ethanol, B20 + 10 wt% Ethanol, B20 + 5 wt% Methanol, and B20 + 10 wt% Methanol) were tested including pure diesel from No load to full load engine condition at two different compression ratios (15:1 & 18:1). The results reveal that B20 + 5 wt% Methanol at 15:1 compression ratio outperformed in terms of brake power of 2.64 kW, indicated power of 6.35 kW, brake thermal efficiency of 33.21%, Indicated thermal efficiency of 67.18%, mechanical efficiency of 59.14%, low brake specific fuel consumption of 0.27 kg/kWh at full load. In conclusion, the heterogeneous catalyst obtained from the waste bull bone can be used in biodiesel production, which ensures the efficient usability of the waste bull bone in the fuel-processing sector.

Emission Characterization of Petrol, Ethanol and Spent Engine Oil Blends for Two-Stroke Spark Ignition Engine

Exhaust emission has remained a big global concern in atmospheric change, and has thus, lead to stiffer polices on emission. To achieve the set emission targets different fuel mix and combustion process are continuously been investigated. This work is used to practically model the condition of a two-stroke engine that has run over time whose used lubricating oil finds its way from the sump to the combustion chamber and thus resulting to greater rate of incomplete combustion and higher emission. An exhaust analyser with a deep probe was deployed to access the out-going burnt gasses from a two-stroke spark ignition engine that is fed with multi blends of petrol, ethanol and spent engine oil. The characteristics of the emission constituents were investigated and compared to the global limits set by different organizations such as California Air Resources Board, Environmental Protection Agency in USA, International Council on Clean Transportation, Road Transport Bureau- in Japan, and European Emission Standard Agency, among others. The result shows an increase in , and emissions with samples that contain spent oil as against those with new engine oil which is also more effective. It was also found that samples with higher quantity of ethanol show lower emission of , and gases. This is likely due to interstation of ethanol molecules with that of the spent oil, thus making it more potent for further combustion. This was also supported with the fact that emission was higher in blends with higher quantity of ethanol. Thus, the presence of ethanol in fuel blend used in two-stroke spark ignition engine may be considered to be a source of improvement in combustion and hence a means of reducing emission in two-stroke port operated spark ignition engines.

Comparison of ethanol-, isobutanol-, and 2-methyl-3-buten-2-ol–gasoline sprays from a gasoline direct injector

Sprays of alcohol–gasoline fuel blends from a direct-injector were visualized with a high-speed camera utilizing a diffuse back-illuminated imaging technique. Blends of ethanol, isobutanol (2-methyl-1-propanol), and methylbutenol (2-methyl-3-buten-2-ol) with gasoline were injected into an environment representative of engine conditions. Ethanol was blended at 10, 20, and 30% by volume (E10, E20, and E30). Isobutanol and methylbutenol blends were matched to the ethanol blends on an oxygen weight percent basis resulting in blends of 16, 32, and 49% and 18, 37, and 56% by volume for isobutanol and methylbutenol, respectively. Changes in spray behavior were largely driven by changes in vapor pressure. Low-level blends of isobutanol and methylbutenol behaved nearly identically to the neat base gasoline due to their similar vapor pressures. Higher blends of isobutanol and 2-methyl-3-buten-2-ol reduced flash-boiling while ethanol blends increased it. The ambient-to-saturation pressure ratio was found to be sufficient to describe the flash-boiling transitions for all of the fuels. Measurements of spray width were found to become more dependent on ambient density with downstream distance. It was found that blending isobutanol or 2-methyl-3-buten-2-ol into gasoline in lieu of ethanol can result in significant changes to spray behavior depending on the blend level.

Research on Global Optimization Algorithm of Integrated Energy and Thermal Management for Plug-In Hybrid Electric Vehicles.

Power distribution and battery thermal management are important technologies for improving the energy efficiency of plug-in hybrid electric vehicles (PHEVs). In response to the global optimization of integrated energy thermal management strategy (IETMS) for PHEVs, a dynamic programming algorithm based on adaptive grid optimization (AGO-DP) is proposed in this paper to improve optimization performance by reducing the optimization range of SOC and battery temperature, and adaptively adjusting the grid distribution of state variables according to the actual feasible region. The simulation results indicate that through AGO-DP optimization, the reduction ratio of the state feasible region is more than 30% under different driving conditions. Meanwhile, the algorithm can obtain better global optimal driving costs more rapidly and accurately than traditional dynamic programming algorithms (DP). The computation time is reduced by 33.29-84.67%, and the accuracy of the global optimal solution is improved by 0.94-16.85% compared to DP. The optimal control of the engine and air conditioning system is also more efficient and reasonable. Furthermore, AGO-DP is applied to explore IETMS energy-saving potential for PHEVs. It is found that the IETMS energy-saving potential range is 3.68-23.74% under various driving conditions, which increases the energy-saving potential by 0.55-3.26% compared to just doing the energy management.

Experimental measurements of ultra-lean hydrogen ignition delays using a rapid compression machine under internal combustion engine conditions

In order to mitigate greenhouse gas and pollutant emissions from the transportation sector, the use of green e-fuels is planned. Hydrogen spark ignition engines (H2ICEs) are one of the most important technologies for reducing dependence on fossil fuels. However, these combustion engines are prone to some abnormal combustion phenomena, such as knocking, and require further investigation to get a better understanding of hydrogen combustion properties. This study used a rapid compression machine to present experimental ignition delay measurements of ultra-lean hydrogen/air mixtures under internal combustion engine conditions. The fuel–air ratio ranged from 0.2 to 0.5, the compression temperature varied from 900 to 1030 K, and the compression pressure ranged from 20 to 60 bar. A comparison with often-used and up-to-date hydrogen kinetic mechanisms was performed. The experimental results were consistent and showed an overall good agreement with numerical simulations. The impact of 2 HO2 ⇌ 2 OH + O2 addition on recent kinetic mechanisms was also investigated and presented an average decrease of 20% in ignition delay. Finally, new third-body efficiencies of H2O were evaluated and showed no impact on prediction. The aim of this approach was to provide new experimental data for kinetic mechanism validation and optimization.

Monitoring the operational condition of a diesel engine by evaluating the parameters of its thermodynamic operation cycle

Monitoring the operational condition of a diesel engine by evaluating the parameters of its thermodynamic operation cycle

THE CONTACTLESS DIAGNOSTICS TO DETERMINE THE TECHNICAL CONDITION OF INTERNAL COMBUSTION ENGINES OF HIGH-ENERGY AGRICULTURAL MACHINERY

he paper revealed the possibilities of using contactless diagnostics to obtain digital data obtained over the local network of tractor CAN bus controllers. (Research purpose) The research purpose is analyzing of the nomenclature of indicators of the operational and technical characteristics of the internal combustion engine of tractor equipment and creating modern technologies for diagnostics and control of the technical condition of tractor equipment. (Materials and methods) It was noted that the diagnosis of energy-saturated agricultural machinery (tractors, combines), carried out using external and built-in controls, allows you to determine the technical condition of internal combustion engines without disassembly, predict the service life of their parts, actually manage the technical condition of the engine of the machine. It has been shown that the engineering service of the agro-industrial complex pays great attention to technical diagnostics related to the prevention of failures of the most important components and aggregates of energy-saturated agricultural machinery. It was determined that the performance of these operations has a positive effect on the timing of agricultural work, obtaining an additional volume of agricultural products. For each diagnosed machine (tractor), normative indicators of serviceability (operability) during operation, maintenance and repair must be established. (Results and discussion) It was revealed that the use of contactless diagnostics provides timely detection and elimination of significant malfunctions in the power or ignition systems of engines, transmission units or chassis, improves fuel and economic indicators by 5-10 percent, engine power by 2-3 times, improves environmental performance, increases the safety of machine operation. (Conclusions) In the course of the conducted research, the functionality of diagnostic devices with advanced information collection capabilities – a universal USB CAN bus adapter-was determined.

Some Practical Hints on Preservation of Aircraft Engines Using a Rig from Corrosion Problems

Aircrafts need to be grounded for want of routine scheduled maintenance and inspection after certain period of flying hours. During such maintenance practices, the turbo-propeller engines are kept dismantled, un- installed and non-operative conditions for a longer period even up to two years. During this non-operative period, the engines and components are susceptible to extensive chronic corrosion hazards. To prevent this hazard, the engines and components are required to be preserved both internally and externally from corrosion that is the engine components such as turbine, turbine blades, compressor, fuel nozzles, fuel system pipelines, diffuser, combustion cum mixing chamber, expansion nozzle and exhaust manifold. Over the long experience of operating the aircrafts, it has been observed that the appliance provided by the manufacturer is only meant for internal corrosion preservation purposes of the operative and installed engines and cannot be used for external corrosion preservation of non-operative and un installed engines which led to drastic reduction of engine lives and unsafe operating conditions to the aircrafts due to inherent materialistic corrosive effects. The material of the turbine blades could not able to withstand its designed high combustion temperature due to the corrosion problems, which leads to unsafe engine conditions. The problem was attributable to the design factor that the high pressure cock in the fuel supply system could open and allow the preservative oil to enter into the main fuel system only when sufficient oil pressure is built up in associative oil system, which needs rotating the engines at least in idling speeds. Simulating this mandatory condition is not possible for the non-operative uninstalled engines. To overcome the corrosion hazard problem of aircraft engines, a bogie hinge joint flushing device has been designed, fabricated and tested using the local resources after taking into consideration of this important engine external preservation requirements, layout of the turbo-propeller engine power plant and fuel supply systems. This innovative external preservation rig has got multiple options coupled with internal preservation for preserving the engine components such as turbine, turbine blades, compressor, fuel nozzles, fuel system pipelines, diffuser, combustion cum mixing chamber, expansion nozzle and exhaust manifold during the course of long maintenance period. The newly designed and developed external preservation rig has resulted in achieving the complete external preservation requirements of following categories of turbo-propeller engines. a) New/overhauled engines in storage and kept on expiry of preservation life b)Installed engine required to be removed for storage but cannot be cranked or rotated c) Installed engines that are not in running condition/installation-seized engines d) Uninstalled engine for defect investigations/defect rectifications e) Non operative unsafe engines

Numerical study of controlling a lean mixture autoignition in the hybrid HCCI engine using high frequency corona discharges

A relationship has been established between the ignition timing of the region, activated by a high frequency corona discharge, and the autoignition timing of unburned gas in the hybrid HCCI engine in a propane-air mixture. This relationship depends on the equivalence ratio ϕ: the leaner the mixture, the weaker the dependence. For a richer mixture (ϕ = 0.7), autoignition is a sequential propagation of autoignition waves in unburned gas, in a leaner mixture (ϕ = 0.5) spontaneous ignition right away of the entire volume occurs just in front. It has been shown that autoignition event can be controlled by varying the discharge initiation timing, the configuration of discharge region, and the specific energy input into the streamer channel. These parameters are varied in wide range values, but occurrence of autoignition falls into suitable range of ignition angles corresponding to the optimal operating conditions of HCCI engine. It has been revealed that the controlling the onset of autoignition in a very lean mixture is less effective than in a richer one.

Effect of dopants on soot oxidation over doped Ag/ZrO2 catalysts for catalyzed gasoline particulate filter

Soot oxidation was studied using silver-zirconia catalysts doped with Y, La, Ce and Pr under a low concentration of O2, typical for gasoline direct injection engine conditions, in view of practical gasoline particulate filter application. The Ag/La-ZrO2 catalyst revealed the best catalyst performance for soot oxidation exhibiting a Tmax of 405 °C for a fresh sample and 420 °C after aging at 700 °C for 6 h. Additionally, the doped catalysts exhibited improved activity for co-oxidation of CO and C3H6. The Ag/ZrO2 catalyst benefited from doping via the synergy between silver particles and doped zirconia.

Analysis of the Recovered Power in a Thermoelectric Generator Under Different Operating Conditions of Diesel Engine

Analysis of the Recovered Power in a Thermoelectric Generator Under Different Operating Conditions of Diesel Engine

A Deep Learning-Based Fault Warning Model for Exhaust Temperature Prediction and Fault Warning of Marine Diesel Engine

Marine diesel engines are essential for safe navigation. By predicting the operating conditions of diesel engines, the performance of marine diesel engines can be improved, failures can be prevented to reduce maintenance costs, and emissions can be controlled to protect the environment. To this end, this paper proposes a hybrid neural network (HNN) prediction model (CNN-BiLSTM-Attention) based on deep learning (DL) for predicting the exhaust gas temperature (EGT) of marine diesel engines. CNN is used to extract features from time-series data, BiLSTM is used to predict the time series through modeling, and Attention is used to improve the accuracy and robustness of fault prediction. Moreover, through comparison experiments with other neural network prediction models, it has been proven that the CNN-BiLSTM-Attention method is more accurate. This article also presents an approach to fault prediction by integrating the Mahalanobia distance and the mathematical model. Based on the Mahalanobia distance between the prediction result and the actual value, the function mapping method combined with the criterion is used to set the alarm value and threshold of the monitoring indicators, and the failure data set is used for experimental verification. The results indicate that the approach presented in this article can accurately realize the operating condition monitoring and fault early warning of marine diesel engines, which provides a new way of thinking for the research of fault early warning and health management of marine diesel engines.

Mental health in undergraduate engineering students: Identifying facilitators and barriers to seeking help

AbstractBackgroundEngineering students encounter high levels of stress, which may negatively impact their mental health. Nevertheless, engineering students who experience mental health distress are less likely than their peers to seek professional help, even when controlling for gender and race/ethnicity.PurposeWe examined beliefs that undergraduate engineering students have about barriers and facilitators to seeking professional help for their mental health. We also sought to identify cultural and systemic factors within and beyond engineering that might affect help‐seeking. Together, these beliefs influence students' sense of personal agency around seeking mental health care.MethodWe implemented a pragmatic qualitative design that incorporated the integrated behavioral model to investigate engineering students' (N = 33) professional mental health help‐seeking beliefs. We used thematic analysis to analyze help‐seeking beliefs and perceived barriers and facilitators that students described during interviews.ResultsWe identified four themes: Navigating the system impacts personal agency; sacrifices associated with help‐seeking act as a barrier; engineering culture acts as a barrier to help‐seeking; and student confidence in help‐seeking varies significantly. These themes portray the effect of perceived barriers and facilitators on students' personal agency for accessing mental health care. Our findings have implications for engineering departments and university counseling centers that want to minimize barriers to help‐seeking.ConclusionsEngineering stakeholders must improve access to professional help for engineering students. Implementing changes to normalize help‐seeking behaviors, enhance personal agency, and facilitate engagement with mental health resources will create better conditions for engineers. Further research is necessary to understand how other beliefs (e.g., attitudes, perceived norms) inform the relationships between student mental health, professional help seeking, and engineering culture.

A new method for characterizing the heat transfer capacity of the divertor and high heat flux components

The divertor is usually exposed to extreme incident heat flux conditions in nuclear fusion engineering and its ability to remove the heat is extremely crucial for the safe operation of magnetic confinement nuclear fusion device. The evaluation of the heat removal capacity of the divertor has been always based on high heat flux (HHF) tests. Yet such methods are only available for the small size of experimental components, it is more difficult to compare under different loading and cooling conditions. In order to assess the heat removal capacity in real time and accurately, a new method was developed to characterize the heat removal capacity of the divertor and other high heat load components based on the cooling water thermal decay time constant, the time constants model has also been established. The thermal decay time constant was obtained by fitting the characteristic curves of the water temperature differences with time during the cooling phase of different components under HHF tests. This index is used to quantitatively analyze, characterize and evaluate the heat transfer capacity of the system of the divertor.

Development of multi-component surrogate fuel for marine diesel considering fuel physical-chemical properties

Herein, as an alternative to heavy fuel oil (HFO), a multi-component surrogate fuel was developed, consisting n-tetradecane (6.36 %), n-hexadecane (4.25 %), i-hexadecane (20 %), n-eicosane (15 %), decalin (17 %), toluene (4.45 %), naphthalene (13 %), and phenanthrene (19.94 %). The proportions of the components of the surrogate fuel were determined by studying the chemical and physical characteristics of HFO. The surrogate fuel was optimized by matching the cetane number (CN), density at 20 °C, lower heating value (LHV), and hydrogen-carbon (H/C) ratio. The developed skeletal surrogate mechanism constituted 128 species and 375 reactions. It was extensively validated using various fundamental experiments based on its single components and HFO performance under relevant engine conditions. The predicted ignition delay time in shock tubes and the concentrations of primary species in jet stirred reactors and flow reactors were in good agreement with the previously measured values. The predicted laminar flame speed in counterflow configuration was close to the experimental data. The flame spray and combustion characteristics were found to be well produced by the proposed mechanism in a fuel ignition analyzer and a two-stroke marine diesel engine. The proposed skeletal mechanism exhibited reliable overall performance for combustion behavior, indicating that it can be used for modeling HFO in realistic engine applications.

Impact of titanium dioxide (TiO2) nanoparticles addition in Eichhornia Crassipes biodiesel used to fuel compression ignition engine at variable injection pressure

Power production through combustion of fuels plays a vital role in the progress of a nation. In liquid fuels, biodiesel has emerged as a potential replacement of fossil fuel. In this regard, the improvement of fuel properties or adjustment of the operating parameters can improve the efficiency and lower the emission for a biodiesel run diesel engine. In this regard, the current study focuses on the use of novel nano blended biodiesel, prepared by blending titanium dioxide nano particles along Eichhornia Crassipes biodiesel. Three different biodiesel blends are prepared having composition of titanium dioxide by 50 ppm, 100 ppm and 150 ppm which is tested in a four stroke, single cylinder, naturally aspirated water cooled diesel engine of 3.5 kW rated power for different loading conditions for performance, emission, and combustion evaluation. Further, at the same engine conditions, the biodiesel blend having 150 ppm of titanium dioxide is tested at fuel injection pressure of 220 bar. The findings suggests that the brake thermal efficiency improves and emissions lowers with the addition of nano particles at high fuel injection pressure. The maximum improvement of brake thermal efficiency of 1.01% in comparison to diesel mode has been found for nano blended biodiesel composition of 150 ppm of titanium dioxide at fuel injection pressure of 220 bar under full loading condition. For the same fuel injection pressure of 220 bar and same nano blended biodiesel composition, the hydrocarbon and carbon monoxide emission were found to minimum at 60% load.

Mesenchymal stem cell engineering by ARCA analog-capped mRNA

We previously have shown that mRNA-based engineering may enhance mesenchymal stem cell (MSC) trafficking. However, optimal conditions for invitro mRNA engineering of MSCs are unknown. Here, we investigated several independent variables: (1) transfection factor (Lipofectamine 2000 vs. TransIT), (2) mRNA purification method (spin column vs. high-performance liquid chromatography [HPLC] column), and (3) mRNA capping (ARCA vs. β-S-ARCA D1 and β-S-ARCA D2). Dependent variables included protein production based on mRNA template (measured by the bioluminescence of reporter gene luciferase over hours), MSC metabolic activity corresponding with their wellbeing measured by CCK-8 over days, and endogenous expression of genes by RT-qPCR related to innate intracellular immune response and decapping at two time points: days 2 and 5. We have found that Lipofectamine 2000 outperforms TransIT, and used it throughout the study. Then, we showed that mRNA must be purified by HPLC to be relatively neutral to MSCs in terms of metabolic activity and endogenous protein production. Ultimately, we demonstrated that β-S-ARCA D1 enables higher protein production but at the cost of lower MSC metabolic activity, with no impact on RT-qPCR results. Thus Lipofectamine 2000-based invitro transfection of HPLC-purified and ARCA- or β-S-ARCA D1-capped mRNA is optimal for MSC engineering.

Optimization of Pressure Management in Water Distribution Systems Based on Pressure-Reducing Valve Control: Evaluation and Case Study

Leakage in water distribution systems (WDS) is a major problem that results in substantial resource wastage. Pressure management, which is based on optimized control strategies using pressure-reducing valve installation, is considered one of the most effective methods for controlling network leakage and can be broadly classified into varied types, depending on the different control strategies. When facing diverse operational conditions in actual engineering, selecting the most suitable optimization strategy for the specific water supply network can greatly control leakage and efficiently utilize water resources. This article employs a greedy algorithm to iteratively determine the control sequence for pressure-reducing valves (PRVs), with the objective of minimizing surplus pressure. Subsequently, it proposed five evaluation indicators, namely, daily flow, daily leakage, pressure imbalance indicator, median daily pressure at nodes, and water age, which are used to evaluate and compare pressure management strategies in two sample networks. Finally, a suitable control strategy was successfully developed and implemented for an actual WDS of Y city in southern China, resulting in significant achievements. In conclusion, this paper embodies our attempt and contemplation in formulating pressure management strategies under diverse operating conditions in WDS, with the objective of providing guidance for practical engineering applications.

Research on Diesel Engine Fault Status Identification Method Based on Synchro Squeezing S-Transform and Vision Transformer.

The reliability and safety of diesel engines gradually decrease with the increase in running time, leading to frequent failures. To address the problem that it is difficult for the traditional fault status identification methods to identify diesel engine faults accurately, a diesel engine fault status identification method based on synchro squeezing S-transform (SSST) and vision transformer (ViT) is proposed. This method can effectively combine the advantages of the SSST method in processing non-linear and non-smooth signals with the powerful image classification capability of ViT. The vibration signals reflecting the diesel engine status are collected by sensors. To solve the problems of low time-frequency resolution and weak energy aggregation in traditional signal time-frequency analysis methods, the SSST method is used to convert the vibration signals into two-dimensional time-frequency maps; the ViT model is used to extract time-frequency image features for training to achieve diesel engine status assessment. Pre-set fault experiments are carried out using the diesel engine condition monitoring experimental bench, and the proposed method is compared with three traditional methods, namely, ST-ViT, SSST-2DCNN and FFT spectrum-1DCNN. The experimental results show that the overall fault status identification accuracy in the public dataset and the actual laboratory data reaches 98.31% and 95.67%, respectively, providing a new idea for diesel engine fault status identification.

Ducted Fuel Injection Provides Consistently Lower Soot Emissions in Sweep to Full-Load Conditions

<div>Earlier studies have proven how ducted fuel injection (DFI) substantially reduces soot for low- and mid-load conditions in heavy-duty engines, without significant adverse effects on other emissions. Nevertheless, no comprehensive DFI study exists showing soot reductions at high- and full-load conditions. This study investigated DFI in a single-cylinder, 1.7-L, optical engine from low- to full-load conditions with a low-net-carbon fuel consisting of 80% renewable diesel and 20% biodiesel. Over the tested load range, DFI reduced engine-out soot by 38.1–63.1% compared to conventional diesel combustion (CDC). This soot reduction occurred without significant detrimental effects on other emission types. Thus, DFI reduced the severity of the soot–NO<sub>x</sub> tradeoff at all tested conditions. While DFI delivered considerable soot reductions in the present study, previous DFI studies at low- and mid-load conditions delivered larger soot reductions (>90%) compared to CDC operation at the same conditions. Therefore, the DFI configuration used here has been deemed nonoptimal (in terms of parameters such as the injector-spray and piston geometries), and several improvements are recommended for future studies with high-load DFI. These improvements include employing better spray-duct alignment, a deeper piston bowl with a smaller injector umbrella angle, and a fuel injector that opens and closes faster. The study also suggests future research to make DFI ready for commercialization, such as metal-engine tests to ensure desirable DFI performance over an engine’s complete speed/load map. Overall, this study supports the continued development and commercialization of DFI to meet upcoming emissions regulations for heavy-duty vehicles. Specifically, multicylinder engine experiments and CFD simulations should be utilized to optimize the performance and clarify the full potential of DFI.</div>