Rotary Engine Research Articles

Design Challenges in Hydrogen-Fueled Rotary Engine—A Review

The rotary engine (RE) is a potential power plant for unmanned aerial vehicles (UAVs) and automobiles because of its structural and design merits. However, it has some serious drawbacks, such as frequent maintenance requirements and excessive fuel consumption. This review paper presents the current status of hydrogen-fueled rotary engine (HRE) technology and identifies the existing research and development gaps in combustion efficiency and performance of this engine that might benefit transportation sector. Focusing primarily on the research from past ten years, the crucial challenges encountered in hydrogen-powered rotary engines have been reviewed in terms of knock, hydrocarbon (HC) emissions, and seal leakages. The paper identifies the recent advances in design concepts and production approaches used in hydrogen-fueled rotary engines such as geometric models of trochoid profiles, port configurations, fuel utilization systems, and currently available computational fluid dynamics (CFD) tools. This review article is an attempt to collect and organize literature on existing design methods up to date and provide recommendations for further improvements in RE technology.

Desempenho do trator agrícola com diferentes distribuições de massa entre eixos

ABSTRACT: An adjustment of the agricultural tractor is necessary to achieve energy efficiency, which can be done through the correct distribution of mass between the axles for each operating surface. This research evaluated different distributions of mass between axles in a 93 kW tractor equipped with auxiliary front-wheel drive, on two soil surfaces. The experiment was carried out in strip design, with a double factorial scheme (2 x 3), with two soil surfaces (mobilized and firm) and three mass distributions between axes (35/65%, 40/60% and 45/55%), with five repetitions, totaling 30 parcels. The slippage parameters of the front and rear wheelset, engine rotation, hourly and specific fuel consumption, force, power and yield on the drawbar, displacement speed, engine thermal efficiency, traction coefficient, rolling resistance, and yield in traction. On firm soil, the energy performance of the tractor was superior in relation to the mobilized one, which allowed greater tractor and drawbar performance with lower specific fuel consumption. The use of a 35/65% between-axle mass distribution provided maximum traction for the mechanized set, resulting from the reduction in energy expenditure generated by skating and; consequently, the maximum use of the energy made available by the mechanized set. However, the maximum conversion of energy contained in the working fuel is obtained with the 45/55% setting.

РЕАЛЬНІ ОПЦІОНИ ЯК ФІНАНСОВІ ІНСТРУМЕНТИ СПРИЯННЯ ВІДБУДОВІ ПІСЛЯВОЄННОЇ ЕКОНОМІКИ УКРАЇНИ

Using the example of the Ukrelektromash plant, the application of various types of real options is considered depending on the development of the project scenario for the production and sale of rotary hybrid engines. The conditions and criteria for the application of option mechanisms are defined, taking into account the impact of risks, which is reflected in the assessment of the probabilities of the development of one or another type of scenario. The effectiveness of using abandonment and switching real options to a related type of activity in the event of a pessimistic development of cash flow and options to expand and replicating experience real option in the event of an optimistic scenario has been proven. At the same time, the degree of effectiveness of the manager's actions is shown, depending on the results of the project's cash flows after the first year of implementation. It has been established that real options are able to generally increase the strategic value of international investment projects, creating conditions for the post-war reconstruction of Ukraine's industry and encouraging the cooperation of foreign investors. In this way, the use of real options enables the manager to take effective measures to manage risks and cash flows, improving the degree of attractiveness of investment projects, and thereby opening new opportunities for cooperation with foreign partners. The implementation of programs with the use of real options becomes necessary when the investor is wary of investing in the development of the country after the end of the war, and at the same time sees great potential for the development of various sectors of the economy. Reducing the degree of riskiness of projects with the help of real options contributes to the gradual restoration of industrial capacities, the acceleration of money circulation, and the improvement of trade and financial operations on international markets.

Output Feedback Speed Control for a Wankel Rotary Engine via Q-Learning

This paper develops a dynamic output feedback controller based on continuous-time Q-learning for the engine speed regulation problem. The proposed controller is able to learn the optimal control solution online in a finite time using only the measurable outputs. We first present the mean value engine model (MVEM) for a Wankel rotary engine. The regulation of engine speed can be formulated as an optimal control problem that minimises a pre-defined value function by actuating the electronic throttle. By parameterising an action-dependent Q-function, we derive a full-state adaptive optimal feedback controller using the idea of continuous-time Q-learning. The adaptive critic approximates the Q-function as a neural network and directly updates the actor, where the convergence is guaranteed by employing novel finite-time adaptation techniques. Then, we incorporate the extended Kalman filter (EKF) as an optimal reduced-order state observer, which enables the online estimation of the unknown fuel puddle dynamics, to achieve a dynamic output feedback engine speed controller. The simulation results of a benchmark 225CS engine demonstrate that the proposed controller can effectively regulate the engine speed to a set point under certain load disturbances.

The effect of hydrogen additives on fuel consumption and hydrocarbon emissions in gasoline fuelled Wankel rotary engine

Experimental data for Wankel rotary engine performance on hydrogen blends with hydrocarbon fuel is presented. Researches are performed on partial loads and idle. Hydrogen mass fraction additions to the fuel mixture didn’t exceed at partial loads 5% and idle mode 9%. The excess air ratio was stoichiometric. It is shown that for partial loads (20% of full load) and engine speed 2000 rotary per minute 5% hydrogen addition yields to 4.2% decrease of brake specific fuel consumption (hydrogen consumption was converted to gasoline consumption computed proportionally to their combustion heats ratio). Amount of unburned hydrocarbons for the conditions mentioned reduces in a factor of 1.8 and emission of carbon monoxide in a factor of 2.3. Hydrogen addition notably increase effective leaning limit, thus for idle mode tests Wankel rotary engine showed steady performance even for excess air ratio 1.16, while in the absence of addition instability displayed itself for excess air ratio exceeding 0.95.

Whole-plant corn silage harvesting modalities: energy efficiency and operational performance.

The need for energy rationalizing in farming operations require research that optimize grain crop conduction. The operations used in the processing and production of silage have limitations in energy optimization due to the lack of studies. This paper evaluated energy efficiency of whole-plant silage operations with the objective of favor the decision making. The adopted design of the experiment was in parcels (with seven replications), consisting of three harvesting modalities: single-line forage harvester, total area forage harvester, and total area forage harvester with support transshipment. The tractors were instrumented with sensors that measured engine rotation, travel speed, and hourly fuel consumption which were used to calculate field capacity, fuel consumption per area and per harvested mass, and production capacity of the harvester-tractor set. The results went to analysis of variance and subsequently to Tukey's test. The single had a faster speed and lower hourly fuel consumption, but smaller field capacity and greater energy expenditure for the mass. The use of support transshipment set with the front harvester allowed an improvement in the operation, with an increase in the worked area, and material processing (18%), and speed (13%), without differing in fuel expenditure. The total-area forage harvester modality showed smaller costs (USD 6.7), followed by the total-area forage harvester with support transshipment set (USD 7.7) and the single-line forage harvester (USD 9.38), respectively. The use of forage harvesters with a wider working width proved to be more efficient in terms of production costs per harvested hectare, validating it's reccomendation.

Identification of Engine Rotation Speed Control System Installed in Research Aircraft “Hisho''

Identification of Engine Rotation Speed Control System Installed in Research Aircraft “Hisho''

The Simulation of Combustion Characteristics from Diesel Fuel and Biodiesel in Different Engine Rotation

The combustion characteristics of fuel are important to understand. Diesel engines can ruin by using fuel from diesel and biodiesel. The characteristics between biodiesel and diesel fuel are different. Diesel fuel has low viscosity, high volatility, low density, and cetane number is around 48. However, biodiesel has high density, low volatile, high viscosity and has higher cetane number than diesel fuel. Using biodiesel can reduce the particulate matter from the engine. This happened because biodiesel has high oxygen content and can reduce emissions. These are some advantages of using biodiesel in diesel engines. In this research, the simulation of the combustion characteristics were investigated by diesel-rk simulation. The fuels are diesel fuel and biodiesel made from soybean methyl ester (SME). In this simulation, pure diesel fuel (DF), SME100, SME20 (20%SME blends to 80%DF) and SME40 (40%SME blends to 60%DF) are investigated. The combustion was set up with 1500, 1800, and 2000 rpm. The results show that in all engine rotations, DF has higher Specific Fuel Consumption (SFC) than SME. Moreover, the NO2 emission from DF is lower than SME. However, the particulate matter in SME40 can reduce up to 16.1% compared to DF. Moreover, the higher the engine rotates, the emissions from NO2 and PM from SME20, SME40, and DF can be reduced. It can be confirmed that the higher rotation in the engine can decrease the emissions in the engine. In addition, biodiesel can be replaced with diesel fuel and it is environmentally friendly.

An Addition of Ethanol and Patchouli Oil on Pertamax: The Case Study of Their Effect on Exhaust Gas Emission for 4-stroke Engine

Industrial sector has been focused on the transportation and automotive service due to their essential for many people in every daily life. Currently, almost everyone has a motorized vehicle which also has an effect on improving the country’s economy. On the other hand, this raises concerns about the occurrence of a global warming phenomenon. The more motorized vehicles were extremely impact on increasing the exhaust gasses that also have a negative impact to the environment, including carbon monoxide (CO) and carbon dioxide (CO2). Hence, this work tried to reduce the exhaust gas emission through the addition of ethanol and synthetic additive, namely patchouli oil. This case study was conducted using pertamax fuel with octane number 92. We analyzed five different optimization sample that consisting of S1, S2, S3, S4, and S5. Then, the several characterizations also carried out to these samples for supporting the results obtained i.e. density, viscosity, and surface tension. Also, the variation of engine rotation speed (in rpm) is utilized to determine the performance or the impact of the samples made to the environment. The results indicate that the pertamax sample mixed with ethanol and patchouli oil showed an optimal performance in S5, there is no detect of CO emission. Then, S3 for the lowest emission of CO2. Also, S3 for the highest efficient in fuel consumption. Hoping this work has an extremely impact for the reducing an exhaust emission in fuels and increasing the energy efficient of internal combustion engines

Design and optimization of orifice plates in the air-assisted kerosene injection system applied in the wankel rotary engine

Pressure stabilizing performance of orifice plates is analyzed by the method of simulation. To guarantee the high efficiency of analysis, an orthogonal table designation L9(34) is established. Range analysis is performed by using the method of orthogonal design. In the meantime, the results show that the number of horizontal plates is the main influence factor of pressure stabilizing performance. By analyzing flow characteristics, internal flow performance of pressure stabilizing cavity is demonstrated. Simultaneously, the mechanism of optimal pressure stabilizing performance is illustrated from both global and local perspectives. Increasing the number of horizontal plates reduces flow area of the cavity and brings extra throttling loss, thus improving the performance of pressure stabilizing. The final design of orifice plates can accurately control the amount of fuel injection which in turn guarantee the reliability of the air-assisted injection system.

Synthesis of the system for controlling the distance between vehicles

Problem. In conditions of high traffic intensity, it often happens that shortly after turning on the car's speed control mode, the driver has to brake in order to maintain a distance from other road users moving at variable speeds. The work analyzed the remote control system, considered the remote control system and car control, considered the sensors of the automatic control system, selected the control law, analyzed the control object, the structural diagram of the distance. A control system was developed and the transfer coefficient of the control law was determined. Goal. As a result of the analysis, the goal of the study was highlighted: to conduct a synthesis of the remote control system. Methodology. The main method of solving this problem is the study of the differential equations of the control system and the selection of optimal controller parameters that ensure the necessary quality of the transition process. Results. The result of the study is: a two-circuit distance control system, containing the circuits for regulating the engine rotation speed and the distance to the car driving ahead which meets the requirements of the task, if the P-regulator is used in the speed control circuit, and a PD-regulator is used in the remote control circuit. Originality. The originality lies in the fact that the introduction of the distance maintenance function into the car's speed control system contributes to a comfortable ride and reduces the likelihood of a stressful situation. Practical value. The use of the proposed results indicate the possibility of developing an automatic distance control system with specified quality parameters.

A Review of Shock Wave Compression Rotary Engine Projects, Investigations and Prospects

Compression by shock waves is a specific way of compressing gases. It has been practically applied for many years in supersonic flying objects. The idea of using this method in rotary engines is extremely appealing because one disk can replace several or a dozen disks of an axial compressor, significantly reducing the weight and production costs of the engine and lowering the fuel consumption due to possible increased compression ratio. This paper presents a review of existing technical solutions and the results of published research devoted to the construction of shock wave compression rotary engines: patents, scientific publications describing various research methods, numerical calculations, and the experimental results of unusual technical solutions. The characteristic solutions and problems that arose during the implementation of these methods are presented and described. Judging from the presented overview, these have wide application possibilities, and an enormous intellectual and financial effort has been put into the construction of such engines. Conversely, there is a rather hermetic group of scientists involved in this activity.

Research on the behavior of CO2 on hydrogen-fueled Wankel rotary engine performance

To prevent global warming, vigorously developing hydrogen energy has become one of research focuses of various countries and regions in recent years. Hydrogen-fueled engines have been proven to be a potential alternative to current fossil-fueled engines. Among various engines, Wankel rotary engine (WRE) is praised for its simple structure and excellent dynamic characteristics, which can greatly compensate for the low specific-volume heat value of hydrogen. However, hydrogen-fueled WRE suffers from low efficiency, high NOx emission and severe knock. For methanol-reforming hydrogen-fueled ICEs, CO2 as the by-product can be used as variant-cooled-EGR to improve ICEs performance and prevent abnormal combustion. Therefore, this work researches the behavior of CO2 on the hydrogen-fueled WRE. The work is conducted at 1500 r/min and wide-open throttle. The results show that CO2 has a significant influence on the heat release process of hydrogen-fueled WRE. Due to this influence, when the volume fraction of CO2 in intake (CO2%) is increased from 0 to 19.28%, the brake thermal efficiency can be improved by 8% with a 7% decline in power output. The NO emission has two orders of magnitude of reduction with increasing CO2% from 0 to 19.28%.. In addition, compared with cooled-EGR, CO2 has a better effect on knock suppression. If methanol-reforming to produce hydrogen becomes the mainstream of on-board hydrogen production in the future, the application of CO2 is of great significance.

Influence of Hydrogen Enrichment Strategy on Performance Characteristics, Combustion and Emissions of a Rotary Engine for Unmanned Aerial Vehicles (UAVs)

In recent years, there has been great interest in Wankel-type rotary engines, which are one of the most suitable power sources for unmanned aerial vehicle (UAV) applications due to their high power-to-size and power-to-weight ratios. The purpose of the present study was to investigate the potential of a hydrogen enrichment strategy for the improvement of the performance and reduction of the emissions of Wankel engines. The main motivation behind this study was to make Wankel engines, which are already very advantageous for UAV applications, even more advantageous by applying the hydrogen enrichment technique. In this study, hydrogen addition was implemented in a spark-ignition rotary engine model operating at a constant engine speed of 6000 rpm. The mass fraction of hydrogen in the intake gradually increased from 0% to 10%. Simulation results revealed that addition of hydrogen to the fuel accelerated the flame propagation and increased the burning speed of the fuel, the combustion temperature and the peak pressure in the working chamber. These phenomena had a very positive effect on the performance and emissions of the Wankel engine. The indicated mean effective pressure (IMEP) increased by 8.18% and 9.68% and the indicated torque increased by 6.15% and 7.99% for the 5% and 10% hydrogen mass fraction cases, respectively, compared to those obtained with neat gasoline. In contrast, CO emissions were reduced by 33.35% and 46.21% and soot emissions by 11.92% and 20.06% for 5% and 10% hydrogen additions, respectively. NOx emissions increased with the application of the hydrogen enrichment strategy for the Wankel engine.

Statistically discussing impacts of knock type on the heat release process in hydrogen-fueled Wankel rotary engine

Hydrogen-fueled internal combustion engine is proposed to resist the threat of global warming. Wankel rotary engine (WRE) has been proven to be an excellent hydrogen-fueled power device, which can overcome the shortcomings of hydrogen, such as poor power, serious backfire and large storage volume, to some extent when it is used as fuel in the internal combustion engine. However, due to its unique structure, WRE suffers from severe knock. Therefore, the goal of this work is to investigate the impacts of knock type on the heat release process in hydrogen-fueled WRE. This present work is conducted at 2000 r/min and wide-open throttle. The main results are as follows: In hydrogen-fueled WRE, the peak knock pressure of knock caused by rapid and unstable combustion of hydrogen is usually earlier than CA50 and that of knock caused by spontaneous combustion of end gas is usually later than CA50. The sequence between the crank angle of peak knock pressure and CA50 combined with knock intensity can be used to determine the knock type in hydrogen-fueled WRE. Besides, a means for knock detection is proposed according to the distribution of crank angle corresponding to peak knock pressure. In addition, the distribution of CA0-10, CA50 and CA10-90 of 1000 consecutive cycles under two kinds of knock in hydrogen-fueled WRE are discussed in detail, and regular conclusions are drawn. In particular, the limitation of CA50 as a metric for evaluating knock level is also demonstrated.

Implementation of a novel dual-layer machine learning structure for predicting the intake characteristics of a side-ported Wankel rotary engine

This paper aims to predict the intake characteristics of a side-ported Wankel rotary engine implemented by a novel dual-layer machine learning (ML) structure. The Sobol sequence coupled with a parametric phase control model is performed to generate samples using a three-dimensional dynamic simulation model. Two ML structures are compared to determine the input features, in which the input features of structure A are the port phases, while structure B also contains the geometric features. Compared with Structure A, the regression and generalization abilities of Structure B with different ML methods are generally favorable. Based on structure B, a novel dual-layer structure prediction model is developed using the Gaussian process regression method in which geometric features are used as intermediate variables. The results show that for the prediction of intake loss and volumetric efficiency, the coefficients of determination are greater than 0.99, and the prediction error is less than 1%. In addition, the port full closing timing determines the intake characteristics compared with other port phases. This paper provides novel solutions for predicting intake characteristics to guide practical optimization.

RANCANG BANGUN FUEL FLOW METER UNTUK MENGUKUR KONSUMSI BAHAN BAKAR MESIN SEPEDA MOTOR EMPAT LANGKAH

In general, in knowing the fuel consumption of a motorcycle, motorcycle owners do this by looking at the fuel indicator on the instrument panel marked "F" meaning full, and "E" emergency. However, in the context of learning, these conditions make it difficult for students to read how much vehicle fuel consumption is viewed at each engine rotation (RPM). Referring to these conditions, the need for a fuel consumption meter is absolute. Therefore, the main objective of this research is to produce a fuel flow meter that can function properly to measure motorcycle fuel consumption so that it can be used as a support for gasoline motorbike technology lectures at the Automotive Technology Vocational Education Study Program) Universitas Bhinneka PGRI. This type of research is experimental research. The research object is the 2005 Honda Supra Fit. The standard for measuring fuel consumption is based on SNI 7554:2010 standards. Data analysis used a quantitative descriptive method. Research equipment and instruments used are a fuel meter, stopwatch, tachometer, and blower. The results of this study indicate that the fuel flow meter functions well in measuring fuel consumption. When calculated, from idle to high speed, there is an average increase in fuel consumption of 0.11 liters/hour or 41% at every RPM. This shows that the fuel flow meter can be used as a support for gasoline engine technology lectures.

Effect of a Taper Intake Port on the Combustion Characteristics of a Small-Scale Rotary Engine

Taper intake ports are effective in improving the charging efficiency of small-scale rotary engines (REs), but it is unclear how their structural parameters affect the in-cylinder flow field and combustion characteristics. For this reason, the effects of the diameter-length ratio (D/L) of an intake port on the in-cylinder flow field and combustion characteristics of a small-scale RE were numerically investigated by utilizing a three-dimensional computational fluid dynamics (CFD) model. The results showed that the in-cylinder pressure of the RE did not follow a simple single-directional trend with the D/L of the intake port, but it was divided into three levels, where the peak in-cylinder pressure was at its maximum at the D/L of 0.6 and at its minimum at the D/L of 0.8. The gas flows in the intake port with different values of the D/L were all unidirectional, and they made a difference in the vortexes formed on the leading side of the combustion chamber of the RE, which was the main factor affecting the in-cylinder combustion performance. The vortexes formed on the leading side of the combustion chamber with D/L = 0.6 were maintained for a long period of time, thus promoting the propagation of flame and advancing the center of gravity of combustion. So, the heat release rate and combustion efficiency in the cylinder were increased at the price of a larger increment in nitrogen oxide formation.

Potential improvement in performance and emissions of air-cooled rotary engine using novel enhanced cooling fins

The Wankel rotary engine (WRE) is widely used in the fields of unmanned aerial vehicles and range extenders due to its superior power-to-weight ratio. However, the rotor piston bears an intense thermal load during operation. This study focuses on the implementation of the coupled 1D-3D model. The influence of ECFs on WRE performance characteristics and emissions and improving WRE performance characteristics and emissions at different operating parameters (speeds and hydrogen enrichment) with ECFs are studied. The simulation results demonstrated that radial-fins have a more significant effect, reducing the fire-face's average temperature by 49.03 K and increasing the in-cylinder mass by 6.4 %. Compared with no-fins, radial-fins can increase pressure by 4.4 % and HRR by 5.6 %. At the same time, the NOx is reduced by 15.60 %, and the CO is slightly increased by 0.93 %. At different speeds, the ECF structure can improve the engine performance. The ECFs are more evident at low speeds, which can increase the indicated power by 3.13 % compared with the original engine. Compared with the gasoline-fueled WREs, using radial-fins can lead to more apparent performance improvement for hydrogen-enriched WREs. This paper will provide insight into the feasibility of ECF configuration to improve the performance of WREs in engineering applications.

Information and measurement system of traction transport vehicles

The synthesis of the information and measurement system for traction transport vehicles was performed in the study. It was established that, depending on the purpose, measuring systems are divided into measurement information systems, measurement control systems, measurement control systems, etc. The majority of tractors produced have analog information and measurement systems. The structure of the information and measurement system was proposed, which includes a microprocessor and the following sensors: inertial measurement device (IMP); tractor speed sensor; engine rotation speed sensor; fuel flow meter. The developed information and measurement system allow to determine the parameters of the tractor's functioning more quickly and the operator may choose effective modes of operation by changing the transmission or speed of movement. Depending on the change of the measuring task, the system is called a flexible measurement system. It is determined that the energy assessment is carried out in order to determine the balance of power and the correctness of the choice of energy means for an agricultural machine or to determine the traction characteristics of a tractor. Experimental models of mounted, semi-mounted and trailed agricultural vehicles and implements in a unit with tractors, as well as self-propelled vehicles that ensure the execution of the work process, or experimental models of vehicles driven by an internal combustion engine or an electric motor are subject to energy evaluation. During the energy evaluation, the power consumption of the machine-tractor unit is determined in the modes of operation, in which technological operations are performed stably. Energy assessment of agricultural vehicles and implements is carried out on a specially equipped tractor corresponding to the traction class of the tested vehicle or implement. The developed measurement system refers to technical means of diagnosis and operational control and can be used in agriculture and machine-building industry. It is intended to determine the kinematic, dynamic, power and energy characteristics of mobile vehicles and their elements during road, field and bench tests. Key words: measurement system, sensor, energy assessment, tractor.