bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparative Analysis on Corrosion Behavior on Precipitation Hardened Stainless Steel Weldments for Car Parts
Authors: D Palanisamy , A Gnanarathinam , Pasupuleti Thejasree , Natarajan Manikandan , Kiruthika Jothi , Polanki Vamsinath
Published: November 2023

Precipitation Hardened Stainless Steel (PHSS) is one of the martensitic steels that possess exceptional strength and corrosion resistance. Because of its characteristics, this PHSS is exclusively adopted in numerous engineering uses such as nuclear, chemical and marine industries. Welding is one of the important methods of joining that helps to make weldments with better performance characteristics. Corrosion behaviour is one of the important characteristics that contribute hugely to marine and other corrosion-related environments and also this is the most common problem for most of the manufacturing industries. The goal of this study was to analyze the PHSS weldments’ corrosive behavior and compare it with that of the two commonly used welding processes, namely MIG and TIG. The corrosive properties of the weldments were evaluated using various mediums, such as nitric acid, ferric chloride, and Oxalic acid. The weight loss procedure was utilized to calculate the PHSS weldments’ corrosion rate. The results of the study revealed that the corrosion rate has increased with time. Temperature variations were identified as the primary cause of this phenomenon.
Optimization of Axial Forming Process Parameters through Mathematical Modelling Approach
Authors: Jaiswal Shivam , S L S Hamsi
Published: November 2023

In the present amplifying automobile industry, the usage of modern manufacturing technology for splines has been enhanced extensively in conjunction with the conventional manufacturing process. Axial Forming process is specifically a cold bulk deforming technology for metals that is adequate for manufacturing of the High quality internal/external splines. The Aim of this paper is to study and optimize the process parameters of axial forming process to improve the Overall process performance. Axial Forming process characteristics like forming forces, surface quality, Spline Forming efficiency and Stress-Strain behavior are considered as prima facie to elaborate the process performance. Axial Forming Process is mathematically has to be modelled for Spline with Base Material- 42CrMo4 steel with feed speed in aforesaid encapsulated manufacturing process. The optimum value range of the process parameters helps in achieving the comprehensive optimum effect of small forming force, high product quality, and high forming efficiency and the process parameter selection method can be used reliably in similar studies.
Design and Investigation of Automatic Trash Collecting Machine for Industry
Authors: R Balamurugan , Kumar V Sudhir , Pasupuleti Thejasree , Deepan Kumar Sadhasivam
Published: November 2023

Scrap collection from any location is handled with mortal interference in several places and companies which may be extremely harmful or even dangerous to humanity. The demand for robotization has risen rapidly in recent years, owing to cutting-edge technologies that minimize manpower and threat-taking training directly or indirectly. The main objective of the paper is to study, analyze, investigate the main contribution of waste collecting by workers while cleaning in the Mechanical Industry. In order to ensure the safety of the workers during cleaning we had implemented the Automatic Trash Collecting Machine in the industry. For Fabricating the Trash collecting Machine first we had analyzed the problem in the industry and then we had started the free hand sketch of Trash Collecting Machine. Then the design work of Automatic Trash Collecting Machine is done in the modeling software Catia V5. Then the material selection for our model has been done. We had taken the mild steel for the frame, 4 motors for the conveyor and the movement of the vehicle and a movable trash bin for the disposal of waste and a karcher brush for collecting the waste. Then for the Automatic motion we had used Node mc, IoT and the coding part has done for the model. Then the fabrication work for our model is done and finally the testing part for our model in the industry is demonstrated. After the implementation of the model in the industry the safety of the workers while cleaning has greatly increased.
A Dual-Fuel Model of Flame Initiation and Propagation for Modelling Heavy-Duty Engines with the G-Equation
Authors: Perini Federico , Wright Christopher , Reitz Rolf D. , Hiraoka Kenji , Kamino Takafumi
Published: November 2023

We propose a novel dual-fuel combustion model for simulating heavy-duty engines with the G-Equation. Dual-Fuel combustion strategies in such engines features direct injection of a high-reactivity fuel into a lean, premixed chamber which has a high resistance to autoignition. Distinct combustion modes are present: the DI fuel auto-ignites following chemical ignition delay after spray vaporization and mixing; a reactive front is formed on its surroundings; it develops into a well-structured turbulent flame, which propagates within the premixed charge. Either direct chemistry or the flame-propagation approach (G- Equation), taken alone, do not produce accurate results. The proposed Dual-Fuel model decides what regions of the combustion chamber should be simulated with either approach, according to the local flame state; and acts as a “kernel” model for the G- Equation model. Direct chemistry is run in the regions where a premixed front is not present. The “kernel” front is identified using a fast, sparse Chemical Explosive Mode Analysis (CEMA), and a novel on-the- fly spontaneous flame speed formulation. The G=0 surface is initialized when the front is thick enough to be well-represented on the computational grid; it is then advanced using the G-Equation model with a multi-component flame speed. The model is validated against optical experiments which feature direct- injected Diesel and premixed natural gas. Good accuracy and reliability are seen identifying the flame initiation region, with little user input.
Prediction of the Spontaneous Ignition in a GCI Engine using an Extended Physical Model of the Ignition Delay
Authors: Silvagni Giacomo , Ravaglioli Vittorio , Ponti Fabrizio , Moro Davide , Stola* Federico , Cesare Matteo De
Published: November 2023

With the aim to further reduce and limit pollutant emissions and fuel consumption towards carbon neutrality, researchers and automotive manufacturers have been studying new combustion technologies, such as low temperature combustions, which provide an efficient combustion with low pollutant emissions. Despite innovative combustion techniques, such as Homogeneous charge compression ignition (HCCI) and Gasoline compression ignition (GCI), proved to reduce pollutant emissions and increase efficiency of internal combustion engines, their large-scale deployment has been limited by problems in combustion management and stability. In fact, the challenge related to these innovative combustion techniques consists in the development of new control strategies and new calibration methodologies, which allow to limit their combustion instability.

By relying on the natural phenomenon of autoignition, researchers showed that, to optimize GCI combustion, it is necessary to adopt a multiple injections strategy. The rise in temperature and pressure produced by the premixed combustion of the first injections (long ignition delay) results in a controllable ignition of the main injection, responsible for torque delivery, which burns with an extremely short ignition delay. In the discussed process, the most critical aspect to be managed is the spontaneous ignition of the fuel introduced with the pre-injections, since its long ignition delay is affected by many engine control parameters, because it is very sensitive to the cylinder thermal conditions. As a result, the ignition delay might be strongly affected by a slight variation in the control parameters and, consequently, lead to misfire or knocking. The goal of this work was to develop an extended control-oriented ignition delay model, suitable to improve GCI combustion stability through the proper management of the pilot injections over the whole engine operating range.
A Study on the Mechanism of Piston Ring Rotation of an Engine
Authors: Kanemoto Kaito , Ito Akemi
Published: November 2023

Engine oil consumption must be reduced because it produces particulate matter in exhaust gases and poisons the catalyst in an aftertreatment system. Oil transport upward via piston ring gaps is one of the factors for oil consumption.

It is known that piston rings rotate circumferentially during engine operation, and that oil consumption increases when the ring gaps of multiple piston rings are close to each other. Force acting on a piston ring in the circumferential direction was investigated in a past study [3], and a wave form of the force was measured against the crank angle. Furthermore, the forces were varied according to the measurement position in the circumferential direction. It means that the ring gap tends to stay where the force showed a small value. The force shows a periodic wave form against the crank angle for each cycle, and some parts of the waveform show a correlation with piston slap motion [3].

Piston motion consists of lateral motion, tilting motion and up-and-down motion. In this study, the effect of such motions on the force which rotates the piston ring was investigated respectively using newly developed rig testers. The measured results of the rig tests were compared with the force measured during engine operation, and the mechanism of the ring rotation was analyzed.
Impact of Mixture Inhomogeneity and Ignition Location on Early Flame
Kernel Evolution in a Direct-Injection Hydrogen-Fueled Heavy-Duty Optical
Engine
Authors: Laichter J. , Kaiser S. A. , Rajasegar R. , Srna A
Published: November 2023

An optically accessible hydrogen-fueled, heavy-duty engine was used to
investigate the impact of mixture formation on the early flame kernel
propagation and the resulting combustion cyclic variability. Direct injection
from a centrally mounted medium-pressure outward-opening hollow-cone injector
created a fuel- air mixture with a global equivalence ratio of 0.33. The engine
was operated at 1200 RPM with dry air at an intake pressure and temperature of
1.0 bar and 305 K, respectively. The charge was ignited at three different
locations using focused-laser ignition to allow for undisturbed flame evolution,
and the fuel injection timing and injection pressure were varied to influence
the mixture inhomogeneity. High-speed OH* chemiluminescence imaging through a
piston-crown window allowed for tracking the flame evolution while fluorescence
imaging of anisole seeded into the hydrogen fuel provided two-dimensional
information on the mixture distribution around the ignition location just before
ignition. The results reveal that primarily the in-cylinder bulk-flow motion in
conjunction with injection-induced flow influence the early flame kernel
evolution. Despite the ultra-lean conditions, combustion was fast and fairly
stable under most operating conditions, but the turbulence and inhomogeneity
induced by fuel injection during the compression stroke significantly
accelerated combustion compared to early injection during the intake stroke.
Operating points with highly variable fuel/air mixture distribution near the
ignition location exhibited increased cyclic variability with a few
misfires.
Clarification of Fuel and Oil Flow Behaviour Around the Piston Rings of Internal Combustion Engines: Visualization of Oil and Fuel Behaviour by Photochromism in Gasoline Engine Under Transient Operating Conditions
Authors: Kawamoto Yuki , Inoue Naoki , Ito Yuto , Azetsu Akihiko , Takahashi Shun , Ochiai Masayuki , Stark Michael , Härtl Martin , Jaensch Malte , Preuss Ann-Christin , Pryymak Konstantin , Matz Gerhard
Published: November 2023

Photochromism is a reversible color change phenomenon based on chemical reactions caused by light illumination. In the present study, this technique is applied to visualize the lubricating oil and fuel around the piston rings in the gasoline engine. The oil film was colored with a UV laser and photographed by synchronizing the shutter of a high-speed camera with a flashlight. The color density was evaluated as a value of absorbance, calculated from images taken at two different wavelengths and two different times before and after the coloration. The authors performed photochromism visualization experiments in an engine under motored operation. However, using photochromic dyes that are robust to temperature changes makes it possible to visualize the engine under fired operation. The experiment was conducted mainly by switching to the motored operation for a fixed time between the fired operations. The visualization results showed that during the motored operation, lubricating oil colored on the piston land was transported over the piston ring to the top of the piston. The time variation of the absorbance distribution on the land was quantitatively evaluated. Furthermore, the visualized results by photochromism were compared with the results of oil emission measurement based on mass spectrometry supported by aerosol particle measurement. A time delay was confirmed for the oil in the second land to reach the top of the piston by comparison with experimental results of oil emission measurement. It was also confirmed that photochromism allows visualization of fuel movement in the engine.
Designing high-performance fuels through graph neural networks for predicting cetane number of multicomponent surrogate mixtures
Authors: Kim Yeonjoon , Kumar Sabari , Cho Jaeyoung , Naser Nimal , Ko Wonjong , St. John Peter C. , McCormick Robert L. , Kim Seonah
Published: November 2023

Cetane number (CN) is an important fuel property in designing high-performance fuels in recently diversifying compression ignition engines. We introduce graph neural networks (GNNs) that predict CNs of multicomponent surrogate mixtures when only 2D structures and mole fractions of molecules are given. It considers the influences of mixing multiple components and their chemical structures on CN, reproducing the non-linear blending behavior observed for certain mixtures. We trained the GNNs using the CNs of 1,143 mixtures, and reliable accuracy was achieved with mean absolute errors of 3.4-3.8 from the cross-validation. Lastly, we analyzed the chemical structural effects on non-linear blending behavior.
Comparison of the effect of diesel and hydrogen addition on ammonia combustion characteristics in a marine engine
Authors: Liu Long , Wu Yue , Wang Yang , Wu Jie , Wang Xiqing
Published: November 2023

Ammonia, as a carbon-free fuel, is a promising alternative fuel source for decarbonization of the shipping industry. Nevertheless, the poor flammability and low flame speed restrict its potential application as marine engine fuel. In order to explore the ammonia application feasibility and methods in marine engines, the effects of two combustion promoters, including n-heptane and hydrogen, on improving the ammonia combustion characteristics were compared and discussed theoretically in this study, in terms of flammable intake boundary conditions and laminar flame speed under engine operating conditions. A new detailed reaction mechanism of ammonia/n-heptane dual fuel was developed and validated to characterize the combustion of ammonia and diesel. The results demonstrate that the flammability of ammonia is more sensitive to intake temperature as compared to equivalence ratio and intake pressure. The introduction of n-heptane or hydrogen has been observed to have a noteworthy impact on the combustion characteristics of ammonia, resulting in a decrease in the necessary intake temperature. The promotion effect is more pronounced with an increase in the volume fraction of the combustion promoter. However, n-heptane exhibits a superior ability to support combustion in comparison to hydrogen, which allows significantly lower intake temperature requirement for ammonia combustion, even reaching room temperature levels. The reaction pathway of the ammonia/n-heptane mixture indicated that the OH radicals produced by the low-temperature oxidation of n-heptane play a crucial role in facilitating ammonia combustion. Furthermore, the addition of n-heptane has the potential to significantly enhance the laminar flame speed of ammonia up to 34 cm/s, when a 10% volume fraction of n-heptane is employed. Ultimately, the map of NOx and unburned hydrocarbon emissions was illustrated, followed by the proposal of a stratified charge combustion approach aimed at the simultaneous reduction of unburned hydrocarbon and NOx emissions.
Vehicle Simulations development to predict Electric field level distribution based on GB/T18387 measurement method
Authors: Miwa Keishi , Watari Toshio , Nishimura Hiroyuki , Ogawa Hiroki
Published: November 2023

The development of electric vehicles has been progressed, rapidly, to achieve Carbon neutrality by 2050. There have been increasing concerns about Electromagnetic Compatibility (EMC) performance due to increasing power for power trains of vehicles. Because same power train system expands to some vehicles, we have developed numerical simulations in order to predict the vehicle EMC performances. We modeled a vehicle which has inverter noises by numerical simulation to calculate electric fields based on GB/T18387. We simulated the common mode noise which flows through the shielding braid of the high voltage wire harnesses. As a result, it is confirmed a correlation between the electric fields calculated by numerical simulation and the measured one.
Development of New 2.0L Inline 4-cylinder NA Engine for e:HEV
Authors: Kasajima Yuya , Egawa Takeshi , Ushio Nobuhiro , Kondo Toshifumi , Yamaguchi Ryo
Published: November 2023

In recent years, automobile companies have increased the market ratio of electric powertrain vehicles to reduce CO2 emissions. Honda has been selling hybrid electric vehicles (HEV) with two-motor hybrid system since 2012. This system has three drive modes, EV drive mode, hybrid drive mode and engine drive mode. The new 2.0L Inline 4-cylinder engine has been developed to comply with the latest emission regulations around the world, and to enhance the vehicle performance, NV performance, and expansion of high thermal efficiency area of the engine operation.
Effect of Olefin Content in Gasoline on Knock Characteristics and HCHO Emission in Lean Burn Spark Ignition Engine
Authors: Shinabuth Dittapoom , Ohmori Yuya , Kitajima Katsuki , Ono Tomoya , Sakaida, Satoshi , Sakai Yasuyuki , Konno Mitsuru , Tanaka Kotaro
Published: November 2023

In transportation sector, higher engine thermal efficiency is currently required to solve the energy crisis and environmental problems. In spark ignition (SI) engine, lean-burn strategy is the promising approach to improve thermal efficiency and lower emissions. Olefins are the attractive component for gasoline additives, because they are more reactive and have advantage in lean limit extension. However, owing to lower research octane number (RON), it is expected to exhibit the drawback to reducing the anti-knock performance. The experiments were performed using a single-cylinder engine for 6 fuel types including gasoline blends which have difference in RON varying between 90.4 and 100.2. The results showed that adding olefin content to the premium gasoline provided unfavorable effect on auto-ignition as the auto-ignition happened at unburned gas temperature of 808 K which was 52 K lower at excess air of 2.0. Thus, it reduced anti-knock performance. Additional oxygenated fuels such as ethanol and ETBE helped improve the anti-knock performance by 4.9% and 5.7% respectively. S5H+1-hexene fuel was found to be highest reactivity which would have high possibility of knocking. HCHO emission increased linearly with decreasing RON at lean burn condition which was expected to undergo low-temperature reaction processes.
Infrared High-Speed Thermography of Combustion Chamber Wall Impinged by Diesel Spray Flame
Authors: MAHMUD Rizal , TAKAHASHI Tatsuki , KINOSHITA Hiroyuki , SHIMIZU Fumika , NAGANAWA Areno , MOROOKA Masato , AIZAWA Tetsuya
Published: November 2023

As a new method to examine the extremely unsteady and spatially varying wall heat transfer phenomena on diesel engine combustion chamber wall, high-speed imaging of infrared thermal radiation from the chromium coated window surface impinged by a diesel spray flame has been conducted in a constant volume combustion chamber. The infrared radiation from a back surface of the chromium layer was successfully visualized at 10kHz frame rate and 128 × 128 pixel resolution through the window. The distributions of infrared radiation, temperature and heat flux exhibited coherent and streaky structure with radial stripes extending and waving from a stagnation point likely reflecting the near-wall turbulent structure in a wall impinging diesel flame. The experiments were conducted with various parameters such as fuel injection pressure, ambient gas oxygen concentration, wall impinging distance, wall surface roughness and wall materials. Imaging velocimetry analysis was applied to the movement of the radially striped infrared radiation pattern in order to discuss potential correlation between the distributions of the movement velocity and the heat flux. The coherent and streaky radial stripes have been consistently observed at all tested conditions suggesting a potential of near-wall turbulence control, for example by structured surface such as riblets, to reduce cooling loss under varieties of engine operating conditions and engine specifications.
Effects of fuel properties on under-expansion behaviors of flash-boiling jets
Authors: Xu Lubing , Li Yanfei , Liu Zemin Eitan , Tan Guikun , Shuai Shijin , Xu Haifeng
Published: November 2023

The rapid phase change of flash boiling jets would induce under-expansion and affect the spray characteristics, but there is lack of investigations on fuel properties on under-expansion behaviors of flash boiling jets. In this study, high-speed microscopic Schlieren photography was used to capture the near- field shock wave of methanol, ethanol, n-hexane and iso-octane jets under varied conditions. Results demonstrate that the shock size, in terms of shock length and width, are influenced by gas dynamics and thermodynamics of the fuel. An artificial neural network (ANN) was constructed using the key influential parameters, and the predicted results of the optimal models with coefficient of determination exceeding 0.99 are consistent with the experimental results of methanol, indicating that ANN can predict shock size within flash boiling jets and obtains good prediction capability.
A Study on Combustion and Emission Characteristics of Ammonia, Hydrogen and Diesel Tri-Fuel Engines
Authors: Matsunaga Daichi , Tentora Takafumi , Hiraoka Kenji , Toshinaga Kazuteru
Published: November 2023

Ammonia is a promising alternative to conventional fossil fuels for internal combustion engines, especially in the maritime industry, because it does not emit carbon dioxide. Since redundancy is important in marine engines, a dual fuel system with diesel oil is currently widely applied to use alternative fuels such as liquefied natural gas, and a similar system is expected for ammonia-fueled ships. However, ammonia has low ignitability and low burning speed, hence improvement of combustion efficiency is major challenge. In addition, the emission of N2O which has a high global warming effect is also problematic as well as emission of NOX as air pollutant. To overcome these challenges, a mixing with hydrogen, which has high ignitability and high burning speed, can be effective. Therefore, in this study, combustion and emission characteristics of tri-fuel combustion engines, in which ammonia and hydrogen-air mixture is ignited by μ-pilot injection of diesel oil, were investigated. Numerical analysis showed that the increase in combustion temperature due to mixing with hydrogen and reduction in excess air ratio were effective in reducing unburned NH3 and N2O emissions. Experimental results showed that the higher the hydrogen mixing ratio, the shorter the combustion duration. At the same time, unburned NH3 and N2O emissions decreased simultaneously. These results indicate that hydrogen blending is effective in improving combustion efficiency and reducing GHG emissions derived from N2O, while NOX, which increases with increasing combustion temperature, has a trade-off relationship with N2O.
Improvement of efficiency and quietness with Externally Excited Synchronous Motor
Authors: Fan Xu , Wada Hiroki
Published: November 2023

An EESM (Externally Excited Synchronous Motor) consists of a rotor with wound copper wires. One of its benefits is the ability to control the rotor electromagnetically with the rotor current, which is an advantage over an IPMSM (Internal Permanent Magnet Synchronous Motor). To practically use it and achieve optimal NVH quietness performance, the air- gap shape was redesigned to generate a sinusoidal curved magnetic flux density distribution. This differs from the standard design, in which the air gap has the same circumference as the rotor and stator. There was a significant reduction in the high-order magnetic flux density, which did not affect the torque. In addition, there was a reduction in the excitation force and minimal iron loss.

Unlike an IPMSM, which only uses magnets and produces less heat, the copper wires of the EESM rotor generate heat as current flows through them. To maintain power density, it is important to ensure optimal cooling performance. A new cooling structure was developed to compensate for this increase in generated heat. The new cooling structure includes a direct internal oil projection at the rotor hot points and an indirect one at the stator. Finally, as a side effect of the EESM, the high rotation speed causes a large centrifugal force on the rotor wire. The strength reliability was guaranteed using a slot-wedge shape and precision manufacturing. Synchronous control and high-speed, high-precision, as well as high- density layered winding were done to guarantee the manufacturing speed for multipole wire winding.
Numerical Study of Dual Fuel Methanol/Diesel Combustion under Engine-like Condition
Authors: Cung Khanh , Jha Prabhat , Briggs Thomas , Bitsis Chris , Smith Edward , Abidin Zainal
Published: November 2023

Alternative fuels such as methanol can significantly reduce greenhouse gas (GHG) emissions when used in internal combustion engines (ICEs). This study characterized the combustion of methanol, methanol/diesel, and methanol/renewable diesel numerically. Numerical findings were also compared with engine experiments using a single-cylinder engine (SCE). The engine was operated under a dual-fuel combustion mode: methanol was fumigated at the intake port, and diesel was injected inside the cylinder. The characteristic of ignition delay trend as methanol concentration increased is being described at low temperature (low engine load) and high temperature (high engine load) conditions.
Charge Dilution Strategy to Extend the Stable Combustion Regime of a Homogenous Charge Compression Ignited Engine Operated With Biodiesel
Authors: Bukkarapu Kiran Raj , Krishnasamy Anand
Published: November 2023

The present research explores the application of biodiesel fuel in a stationary agricultural engine operated under the Homogenous charge compression ignition (HCCI) mode. To achieve HCCI combustion, a fuel vaporizer and a high-pressure port fuel injection system are employed to facilitate rapid evaporation of the biodiesel fuel. The low volatility of biodiesel is one of the significant shortcomings, which makes it inevitable to use a fuel vaporizer at 380oC. Consequently, the charge temperature is high enough to promote advanced auto-ignition. Further, the high reactivity of biodiesel favors early auto-ignition of the charge. Besides, biodiesel exhibits a faster burn rate due to its oxygenated nature. The combined effect of advanced auto-ignition and faster burn rate resulted in a steep rise in the in-cylinder pressures, leading to abnormal combustion above 20% load. Diluting the charge reduces reactivity and intake oxygen concentration, facilitating load extension. This study explores two charge diluents: recirculated exhaust gas (EGR) and water vapor induction into the intake manifold. With EGR, the maximum load is 40%, whereas 46% of the rated load could be achieved with water vapor induction. The maximum load could be extended up to 50% with the combined dilution using EGR and water vapor. The charge dilution required with water vapor is less than that of EGR. Additionally, charge dilution with water vapor results in better thermal efficiency, fuel economy, and lower emissions than EGR. Overall, the present study confirms the functionality and feasibility of biodiesel in HCCI engines, demonstrating the applicability of charge dilution to address its significant shortcoming of a narrow stable combustion regime.
Effect of Wet Liner Vibration on Ring-liner Interaction in Heavy-duty Engines
Authors: Bradt Casey S. , Wang Yuesen , Tian Tian , Cao Hengchao , Zhu Guixiang
Published: November 2023

Lubricating oil consumption (LOC) is a direct source of hydrocarbon and particulate emissions from internal combustion engines. LOC also inhibits the lifetime of exhaust aftertreatment system components, preventing their ability to effectively filter out other harmful emissions. Due to its influence on piston ring- bore conformability, bore distortion is arguably the most critical parameter for engine designers to consider in prevention of LOC. Bore distortion also has a significant influence on the contact forces between the piston ring and cylinder wall, which determine the wear rate of the ring and cylinder wall and can cause durability issues. Two drivers of bore distortion: thermal expansion and head bolt stresses, are routinely considered in conformability and contact analyses. Separately, bore distortion/vibration due to piston impact and combustion/cylinder pressures has been previously analyzed in wet liner engines for coolant cavitation and noise considerations. However, the effect of piston impact on bore distortion and ring conformability/contact has not been addressed sufficiently in the literature, even though the magnitude of piston impact driven liner deformation can be as high as the thermal bore distortion. This current research explores the addition of the piston impact effect to existing bore distortion and conformability/contact analysis techniques. A simulation workflow is here presented that incorporates piston secondary motion and oil transport, transient structural finite element analysis of the cylinder, and a curved beam ring-liner conformability/contact model. Sample cases are studied with this new technique, focusing on the contact and conformability at the ring gap location. Significantly higher ring-liner clearance and higher contact are observed. As a result, higher oil leakage, wear, and combustion gas blow-by may become substantial and design adjustments may be warranted. This new simulation workflow can be used in power cylinder unit design to potentially reduce LOC, blow-by, and durability barriers to higher efficiency engines.
Development of model-based control system for a low pressure loop EGR with a negative pressure control valve
Authors: Ando Taichi , Yamada Yukiyo , Suzuki Kenji , Yanaka Tomohiro
Published: November 2023

To improve the fuel economy, we developed a turbo-charged spark ignition engine combined with a low pressure loop EGR system. A negative pressure control valve has been applied to achieve high EGR ratio in wide engine operation condition. In this paper, a new developed model-based control system for low pressure loop EGR with a negative pressure control valve will be described.
Highly efficient development of powertrain systems using 1D Real-Time Engine Model
Authors: Ogata Kenichiro , Matsuda Hiromitsu , Kawai Haruna , Shiota Keiji
Published: November 2023

With the promotion of electrification of powertrains, development using the simulation model is being promoted to achieve highly efficient development of the powertrains. Since the hybrid powertrain includes many subsystems, the complexity of the development process bloats the development scale. To proceed with large-scale development efficiently, it is necessary to utilize simulation. Furthermore, to maximize efficiency, improvement in development speed is required. In this study, we selected the real-time technology for 1D engine model that is suitable for the concurrent development aiming at increasing the development speed. The real-time technology achieved a high prediction accuracy, a lower modeling workload, and reliable real-time computation speed. And as a practical application of this technology, we conducted collaborative development of engine and transmission using the real-time engine model.
Air-path System Transient Control of Dual-Combustion- Mode Diesel Engine Based on Universal Sliding Mode Method
Authors: Leng Ling , Chen Tianyu , Shi* Lei , Deng Kangyao , Qu Shuan
Published: November 2023

To address the Multiple Input Multiple Output (MIMO) control problem of air-path system in the combustion mode switching process of diesel engine, the transient control strategy of air-path system needs to be studied. A universal sliding mode controller suitable for all operating conditions was proposed to control the intake state during the transient combustion mode switching process. Therefore, the structure of the MIMO controller was greatly simplified. At the same time, a control-oriented numerical model was established to test the control system performance. It shows that the novel controller can effectively control the transient intake state, especially during the mode switching process.
Together but Alone: Belonging at Return back to School in the Post-Crisis
Authors: Yağan Sevcan , Aydos Emine Hande , Aydın Ebru , Düzyol Türk Endam
Published: November 2023

Aim of the research is to understand the experiences of children at school in the post-pandemic process and examine the belongings of children attending preschool education through the new normal period in the post-crisis. Phenomenological approach was used as a qualitative method. Aligned to this emphasis of the phenomenological approach, it is conducted to give meaning to the perceptions of young children through the concept of belonging regarding school in the new normal. The participants consisted of 12 girls and 12 boys aged between 65 and 78 months, mainly from middle-class backgrounds. Data was gathered via semi-structured interview form, including the questions about being at school in pre-pandemic, receiving distance learning during quarantine, and being at school during post-pandemic to reveal the experiences of children. As the last question of the interview, each child was asked to draw a picture about his/her school, friends, and the teacher. Findings of the study have identified with the phenomenon of “Play: Together but Alone”. Play is also a tool for children to feel a sense of belonging to school and creates opportunities for children to have social, emotional, and physical experiences with their peers. In the study, children's belonging to school has been explained based on "play" and discussed with the themes of social, emotional, and physical belonging.
Estudo de argamassas estruturais com adição de sílica ativa proveniente de resíduos siderúrgicos dosada por empacotamento de partículas
Authors: Fajardo Abner A. , Souza Sílvia R , Bueno Zharry B , Macedo Jordana G , Ferreira Lanna Vinicius , Almeida Fernando do Couto Rosa , Aguilar Maria Teresa P , Garcia Dayana C S , Barbosa Maria Teresa , Santos White J
Published: November 2023

Avaliou-se a inserção de sílica ativa, proveniente de resíduos de siderurgias, nas propriedades mecânicas, físicas, de durabilidade e de microestrutura de uma argamassa estrutural de alto desempenho. O traço das argamassas foi elaborado por meio do empacotamento de partículas. Foram avaliadas as seguintes propriedades das argamassas: resistências à compressão e tração na flexão, absorção de água por capilaridade e por imersão, porosidade, módulo de elasticidade dinâmico, resistividade elétrica, termogravimetria e microscopia eletrônica de varredura. As propriedades mecânicas, físicas e de durabilidade foram mais influenciadas nas primeiras idades pelo cimento e nas idades maiores pela sílica ativa. A dosagem pelo empacotamento de partículas promoveu uma maior densificação da matriz aumentando as propriedades mecânicas e ampliando a durabilidade, possibilitando a geração de argamassas de alto desempenho. Conclui-se que a sílica ativa influencia na evolução das propriedades analisadas e precisa ser considerada no desenvolvimento dos traços de argamassas de alto desempenho.
Produção de material cerâmico incorporado com resíduo de TiO2: estudo das propriedades físico-mecânicas e fotocatalíticas
Authors: Almeida Stephanie L L C , Lied Eduardo Borges
Published: November 2023

O minério não reagido, resíduo gerado durante a produção de dióxido de titânio, apresenta possíveis rotas de utilização na cadeia de produção de materiais cerâmicos, evitando seu descarte em aterros industriais, aproveitando sua propriedade de fotodegradação. O objetivo deste trabalho é investigar o efeito da adição do MNR sobre as propriedades de blocos cerâmicos. Os blocos cerâmicos produzidos foram avaliados em suas propriedades mecânicas, morfológicas, granulométricas, fotocatalítica, mineralógicas e químicas. Os resultados obtidos indicaram que o MNR não comprometeu negativamente as propriedades mecânicas estudadas. A adição do MNR afetou significativamente as propriedades fotocatalíticas e de resistência, promovendo a melhora dessas características, e não afetou significativamente as propriedades físicas de massa específica aparente e de retração linear. A partir dos resultados obtidos, conclui-se que a adição de MNR não prejudica nenhuma propriedade fundamental dos materiais cerâmicos produzidos e pode ser incorporada ao processo, substituindo matérias-primas tradicionais, promovendo um melhoramento da matriz cerâmica e apresentando a capacidade de promover fotocatalise avançada gerando a degradação de sujidades na superfície.
Potencial do uso dos resíduos industriais originados no estado de Minas Gerais como precursores geopoliméricos
Authors: Carvalho Aldo Ribeiro de , Castro Mendes Júlia , De Oliveira Thaís Mayra , Jorge Brigolini Silva Guilherme
Published: November 2023

Para o desenvolvimento econômico mais sustentável do país, é fundamental a reinserção de subprodutos industriais no ciclo produtivo. Existem várias opções de materiais inovadores nos quais é possível incorporar resíduos, e um exemplo são os geopolímeros, que são ligantes para a construção civil compostos de um material precursor e um agente ativo. Nesse aspecto, o objetivo desse trabalho é estudar alguns dos principais resíduos gerados no estado de Minas Gerais, resíduos de concreto, de mármore, de barragem de minério de ferro e de cerâmica vermelha, como potenciais precursores geopoliméricos. Para isso foi realizada uma revisão bibliográfica, seguida da caracterização física desses materiais. Além de identificar os principais aspectos dos precursores que influenciam nos geopolímeros, este trabalho verificou que é possível adotar esses resíduos como precursores geopoliméricos. Com isso, seu reaproveitamento em larga escala tem o potencial de mitigar os impactos ambientais causados por essas indústrias e o consumo de recursos naturais pela construção civil.
Análise do comportamento de prismas de alvenaria confeccionados com tijolos modulares de solo-cimento-RCD
Authors: Valim Fernanda , Santos White , Gutierrez Nelci , Silva Leonardo Martins e , Zanatta Katia Cristina
Published: November 2023

Nesta pesquisa investigou-se a resistência à compressão e o módulo de elasticidade de prismas confeccionados com tijolos vazados de solo-cimento-RCD (50%-10%-50%, em massa), com idade avançada (530 dias), unidos por uma junta de argamassa de assentamento convencional de 5 mm. Realizou-se a caracterização do solo e da mistura do Solo-Cimento-RCD. Avaliou-se a resistência à compressão, módulo de elasticidade e o modo de falha dos prismas. O fator de eficiência dos prismas foi de 57%, valor esperado e condizente com outros autores. O modo de falha observado foi de tração nos tijolos e posterior propagação de trincas nas juntas, apresentando comportamento similar a materiais de ruptura frágil. As equações propostas pela normalização brasileira para tijolos de concreto foram as que obtiveram maior proximidade com os valores encontrados nessa pesquisa. Ressalta-se, contudo, que o comportamento mecânico desse tipo de alvenaria precisa, ainda, ser melhor estudado.
Caracterização mecânica do concreto reforçado por fibras de limalha de aço
Authors: Carvalho Mello Paulo Henrique , De Miranda Saleme Gidrão Gustavo , Paula Sossai Altoé Silvia
Published: November 2023

A crescente produção de peças metálicas por processos de usinagem ocasiona também o aumento na geração de resíduos, denominados como limalha de aço. A utilização deste no concreto podem ocasionar melhoras significativas nas propriedades mecânicas, tais como resistência a compressão e tração, esta incorporação pode ser realizada como substituição ao agregado do concreto e podendo possuir comportamento fibroso no mesmo. Foram avaliados concretos com substituições de areia por limalha de aço, nas proporções de 5%, 10% e 15% em relação a massa de cimento, obtendo acréscimos em ambas as resistências para todas as substituições realizadas, com o maior acréscimo obtido na faixa de 10%, com valor de 73,70% a mais de resistência tanto a tração como a compressão, com grau de confiabilidade de 95% de acordo com análise estatística de variância (ANOVA) realizada.
Análise comparativa da carbonatação no ciclo de vida e da cura carbônica de argamassas mistas com uso de biocarvão para sequestro de carbono
Authors: Neves Junior Alex , Oliveira Elias Franco , Silva Thaís Xavier
Published: November 2023

A indústria cimenteira é responsável com até 8% das emissões globais de CO2. A substituição por processos mais sustentáveis tem motivado a pesquisa de novos materiais de construção civil, que possam mitigar os efeitos do aquecimento global. O biocarvão (biochar) obtido a partir da pirólise de diferentes biomassas é um desses materiais suplementares alternativos e o uso da carbonatação, para sequestro de carbono, uma tecnologia reconhecida. O objetivo deste trabalho é avaliar comparativamente, a carbonatação no ciclo de vida e na cura carbônica, de argamassas mistas com biocarvão nos teores de 5% e 20% de substituição do cimento. Foram realizados ensaios de resistência à compressão, absorção por capilaridade, indicador químico de pH e avaliação da captura de CO2 no ciclo de vida e através da cura carbônica. As argamassas com biocarvão, carbonatadas naturalmente em ambiente interno e acelerado, apresentaram aumento na captura de carbono e na resistência mecânica.
Estudo sobre a substituição parcial do agregado miúdo natural por reciclado proveniente de resíduos de tijolos cerâmicos na produção de argamassa estrutural
Authors: Parente Luiza Gomes Corrêa , Castro Luciana Dias Martins da Costa , Garcia Dayana Cristina Silva , Santos White J
Published: November 2023

A extração de insumos minerais faz com que a construção civil seja um dos setores que mais provoca impactos ambientais. Os agregados da construção civil (brita e areia) são os insumos mais consumidos atualmente no mundo, portanto, a reciclagem dos resíduos da construção e demolição tem sido uma das alternativas na redução desses impactos. Resíduos cerâmicos possuem propriedades inertes e, por isso, sempre trazem dificuldades para a organização e sociedade, exigindo tratamento especial desses materiais e afetando os custos comerciais. O presente trabalho apresenta resultados de ensaios de resistência à compressão, tração, absorção de água, porosidade e massa específica de argamassa com substituições de agregado natural por agregado reciclado proveniente de resíduos de tijolo cerâmico. Os resultados mostraram que os resíduos cerâmicos provenientes da construção e demolição podem ser utilizados para produção de argamassas estruturais.
Panorama atual dos estudos sobre reaproveitamento de resíduos na construção civil brasileira
Authors: Soranço Laura , Oliveira Sandilla , Ribeiro Renato , Carelli Mayara , Barbosa Maria Teresa
Published: November 2023

O objetivo deste estudo é identificar as pesquisas mais relevantes sobre o reaproveitamento de resíduos no Brasil entre 2018 e 2023, por meio de uma revisão abrangente da literatura. São abordados resíduos como rochas ornamentais, resíduos de construção e demolição (RCD), rejeitos de barragem, materiais como bambu, caroço de açaí, bagaço de cana, casca de arroz, EPS, fibra de coco, gesso, PVC, EVA, borracha de pneu, vidro, louça sanitária, lodo de estações de tratamento de água (ETA) e rejeitos de madeira. A pesquisa revela que a inclusão de resíduos vegetais em compósitos reduz o peso específico com melhorias nas propriedades mecânicas, enquanto a adição de polímeros frequentemente tem efeitos opostos. No contexto dos resíduos da construção, são observados resultados variados, mas em sua maioria contribuem para o aumento da resistência mecânica. Os resíduos estudados demonstram viabilidade significativa para reaproveitamento, resultando em diversos benefícios, otimização de custos e redução de impactos ambientais.
Eficiência da moagem de pós (<0,15 mm) reciclados de resíduos da construção civil (RCC) na presença de aditivo
Authors: Risson Kathleen Dall Bello de Souza , Stopassoli Juliana Abatti , Proença Melissa Pastorini , Oliveira Dayana Ruth Bola , Zara Kátya Regina de Freitas , Possan Edna
Published: November 2023

Esse estudo tem como objetivo avaliar a eficiência da moagem com uso de aditivo sobre o tamanho das partículas e a superfície específica (BET) de pós (<0,15 mm) reciclados de Resíduos da Construção Civil (RCC). Para isso, utilizou-se como referência o pó de concreto (PC) e o pó misto (PM), obtidos através da cominuíção respectivamente de corpos de prova de concreto e de areia reciclada mista (materiais cerâmicos e cimentícios). Os pós de RCC foram submetidos ao processo de moagem em moinho de bolas planetário, em diferentes tempos (30, 60, 120, 180 e 240 minutos), teores (0,05, 0,1, 0,5 e 1%) e tipos de aditivos (propilenoglicol, hexametafosfato de sódio e trietanolamina). Diante dos resultados, verifica-se que o tratamento mais eficiente para o pó de concreto foi o de 60 minutos com o aditivo propilenoglicol no teor de 1%. Para o pó misto, devem ser verificados outros teores de aditivos, caso haja a necessidade de um material mais fino.