AVL BOOST Software Research Articles

SIMULATION OF TORQUE VARIATIONS IN A DIESEL ENGINE FOR LIGHT HELICOPTERS USING PI CONTROL ALGORITHMS

This article presents the results of simulation research of a diesel engine for a light helicopter. The simulations were performed using the 1D software AVL Boost RT. The engine model includes elements such as cylinders, turbine, compressor, inlet and outlet valves, ambient environment definition, and fuel injection control strategy. The simulations aimed to evaluate the engine's response to step changes in the main rotor load, both increasing and decreasing power demands. Parameters analyzed included power deviation, torque, engine rotational speed, and stabilization time of the main rotor rotational speed. All tests were conducted using a single set of PI controller settings. The results demonstrate that these parameters are dependent on the magnitude of the step change in the main rotor load demand. The study compares the maximum engine rotational speed deviation from the nominal value for both increasing and decreasing main rotor load demands. The findings indicate that using PI regulator to control rotational speed in the diesel engine in a light helicopter significantly depends on the change in the load torque on the rotor.

Parameter optimisation of marine four-stroke engine EGR systems using RSM and NSGA-III

ABSTRACT To reduce NOx emission of marine engines, an engine parameter optimisation method combining response surface method (RSM), Bayesian neural network and non-dominated sequence genetic algorithm (NSGA-III) is proposed. First, a simulation model of a marine four-stroke engine with an external exhaust gas recirculation (EGR) system was established and validated in AVL-BOOST software. Then, the five parameters of EGR valve opening, ignition advance angle, compression ratio (CR), intake valve opening (IVO) and exhaust valve closing (EVC) are selected as the decision parameters, and the three parameters of engine power, brake specific fuel consumption (BSFC) and NOx emission are taken as the target parameters to be optimised. In Design-Expert software, the response surface model is established by using the experimental design approach of central composite design (CCD), and the impact of decision parameters on target parameters are discussed by using response surface analysis. NSGA-III was used for the multi-objective optimisation of parameters, and the accuracy of NSGA-III was improved by the Bayesian neural network. The optimal solution is selected and verified by the technique for order of preference by similarity to the ideal solution (TOPSIS) approach. The results show that when the EGR valve opening is 47.5%, ignition advance angle is −18.99°CA, CR is 14.995, IVO is 15.27°CA and EVC is 7.68°CA, compared with the standard setting, the optimised power is increased by 4.17%, BSFC is reduced by 4.27%, and NOx emissions are reduced by 12.37%. Therefore, the combination of the Bayesian neural network and NSGA-III multi-objective optimisation can improve engine performance while reducing fuel consumption and NOx emissions.

Design of a novel impulse turbine for exhaust energy recovery in a commercial load carrier single cylinder diesel engine

A significant fraction of the fuel energy supplied in a diesel engine is wasted into the atmosphere through the exhaust gases. Although most modern-day diesel engines are turbocharged, a few remain naturally aspirated. Due to technical challenges, single-cylinder engines are not turbocharged and remain naturally aspirated (NA). The intermittent and pulsated exhaust gas flow tends to choke the turbine and increase the back pressure. On the other hand, supercharging a single-cylinder engine leads to superior performance at the expense of fuel efficiency, as a significant fraction of the energy is wasted in the exhaust. The current study employs a novel crank shaft coupled impulse turbine for effective exhaust energy recovery in a supercharged, high-speed, commercial single-cylinder diesel engine. This novel impulse turbo-compounded and supercharged engine layout was simulated using a 1D model developed using AVL BOOST software. Based on the results of the 1D model, the impulse turbine design was carried out. A CFD simulation of the impulse turbine was carried out using commercially available CONVERGE. The major design parameters, including blade profile, blade width, nozzle shape, size and angle, blade angles, blade speed, number of blades, and turbine outlet port opening, were optimized using the CFD software. The simulated results showed that the designed impulse turbine generated 2.67 kW of power, enhancing the power output of the supercharged engine by 21% at the rated operating condition. The turbine efficiency was 68%, considering the available kinetic energy at the exhaust. Simulation results indicate that the impulse turbine compounded supercharged engine could generate 15.4 kW of power, 45% higher than the base NA engine brake power output.

A comparative investigation of the operating performance and emission characteristics of various diesel engines driving the firefighting pump

The investigation of engines with different performances driving the same load-consuming device is necessary for practical applications. In this paper, three diesel engines with varying capacities for driving the same firefighting pump for high-rise residential buildings were studied and compared for their performance, combustion parameters, and emissions by the simulation method. The AVL BOOST software is utilized to establish theoretical combustion models for these engines. The operating balance point of each engine is determined, and the appropriate transmission ratio of the drive train system is proposed to be applied. The results show that the working partial load modes of Model 1 at 91 % engine load and 2970 rpm, Model 2 at 74 % engine load and 2960 rpm, and Model 3 at 57 % engine load and 2490 rpm. The engine works in its higher load mode, producing higher brake specific fuel consumption (BSFC), higher NOx and CO emissions, lower soot formation, and vice versa. The engine operates at its lower load, resulting in decreased BSFC, less NOx and CO emissions, and more soot generation. The results suggest that Model 2 in the present work is the option that can balance the factors of engine power, initial investment cost, fuel consumption economics, and emissions. The findings obtained from this work are the scientific foundations to support the design of the firefighting pump systems when considering comprehensive factors of technical technology, investment cost, and environmental consideration.

Exploring the feasibility of dimethyl ether (DME) and LPG fuel blend for small diesel engine: A simulation perspective

There is a looming global crisis owing to the increase in greenhouse gases and the escalating fossil fuel process. The issue is further compounded by the ongoing conflicts in different places in the world. Hence, there is an urgent need for a bouquet of alternative fuels suitable to power the incumbent internal combustion engine. Among various options available Dimethyl Ether (DME) is a friendly environment fuel, easy to liquefy, and suitable for use in diesel engines, while Liquefied Petroleum Gas (LPG) is another potential alternative fuel suitable for internal combustion engines. The present study is an endeavor to investigate the characteristics of a diesel engine powered with DME-diesel blends as pilot fuel while LPG was used as the main fuel. During engine testing, different blends of diesel-DME were used containing 0%, 25%, 50%, and 75% DME. The AVL Boost software was employed for modeling the engine performance and tailpipe emission. The test fuel combination was successful in running the engine sans any abnormality in sound or performance. The results showed carbon monoxide (CO) and hydrocarbon (HC) emissions were reduced using the test fuel combination while there was a marginal increase in the oxides of nitrogen (NOx) levels. In general, the combination of DME and LPG could be considered as a potential and promising solution to reducing pollutant emissions.

Simulation analysis of a gas engine with various prechamber neck diameters in lean burning condition

The research presented in this paper focused on the simulation analysis of the pre-chamber neck diameter on in-cylinder processes in a large gas engine. The investigation was conducted using AVL Boost software and the implemented PCSI combustion model. The scope of the analysis included different neck diameters from 17 to 26 mm and variations of the ignition timing in the range of 0 to 40 degrees. Using the narrowest ignition chamber neck resulted in the largest inter-chamber throttling effect. This translated into an increase in the maximum pressure in the cylinder, obtaining more heat release and the heat release rate. Further reduction of the constriction below 17 mm led to a rapid pressure increase in the ignition chamber at the start of combustion above the maximum pressure in the cylinder, for which the indicated constriction value was considered limiting.

Studija o projektovanju sistema dizel pumpi za gašenje požara za stambenu zgradu

Currently, on-site diesel firefighting pump systems are significantly necessary for high-rise buildings. This study presents a process for designing diesel fire pump systems for high-rise buildings using AVL BOOST software associated with mechanical calculations. The Kirloskar CPHM 80/32 pump and DESSUN 4DSP-75 diesel engine were selected based on preliminary calculations to match the requirements of Vietnamese standards for a 79-meter building. AVL BOOST software has been used to simulate the full load performance characteristic of the engine; then, a partial load characteristic is determined for the adequate pump that requires input power at a rated speed of about 2975 rpm. The transmission consists of the propeller drive, and flanges were designed to connect the engine and pump. The findings show that utilizing AVL BOOST software is considerably helpful in determining the engine's partial load characteristics, saving time and costs. This study contributes a foundation for practical research to calculate and design the firefighting pump mechanical systems in high-rise buildings.

Numerical investigation on the effects of fueling the Turbulent Jet Ignition gas engine with methane and hydrogen

The modern solution of two-stage combustion, namely the Turbulent Jet Ignition (TJI), enables the combustion of ultra-lean mixtures. Thanks to this solution, it became possible to reduce fuel consumption and, at the same time, to increase the combustion process indicators (including the overall combustion system efficiency). The article presents the results of numerical tests of a heavy-duty engine equipped with the TJI system running on gas fuels. The AVL BOOST software was used to analyze the effects of different fuel injection rates into the pre-chamber and various ignition timing angles, while maintaining a constant global excess air ratio. Increasing the proportion of hydrogen in the pre-chamber resulted in its reduction in the main chamber (the fuel dose was kept constant with different excess air coefficients in each of the chambers). The maximum combustion pressure values in both chambers were investigated. Changes in the amount of heat released and its release rate were determined. As a result of the simulations, different ignition and combustion conditions were presented for the tested fuels. Based on this, maps of fuel dose to prechamber vs. ignition advance angle were drawn up, showing selected thermodynamic indicators of the combustion process.

Performance research and optimization of marine dual-fuel engine based on RSM and NSGA-II

ABSTRACT In order to improve the economic efficiency of the ship when sailing and reduce the engine optimization cost. We propose the Response Surface Methodology (RSM) combined with NSGA-II to optimize the engine parameters. First, a simulation model of a marine four-stroke dual-fuel engine is established in AVL-BOOST software. Then, control parameters such as engine speed, exhaust valve opening (EVO) and compression ratio (CR) are planned by design of experiments. The response surface model was established in Design-Expert software. The significant influence of control parameters on performance parameters was studied by analysis of variance (ANOVA). Finally, with the output power, indicated fuel consumption rate and nitrogen oxide emissions as the optimization objectives. Non-dominated Sequential Genetic Algorithm (NSGA-II) is used to optimize the parameters to improve engine performance and reduce emissions. The results show that the established response surface model has good prediction accuracy. The response surface model visualizes the mathematical relationship between the control parameters and the optimization targets. The ANOVA results show that engine speed, EVO and CR have significant effects on engine performance and emissions. The optimization results show that the engine speed is 793 rpm, the EVO is 145°CA, and the CR is 12.3. Compared to standard settings, the optimized data shows a 3.4% increase in power, a 0.3% reduction in ISFC, and a 6.2% reduction in nitrogen oxide (NOx) emissions. The combination of response surface analysis and NSGA-II algorithm to optimize engine performance and emissions is thereby a feasible method.

1-D ENGINE MODELING OF 4-CYLINDER TURBOCHARGED GASOLINE ENGINE

This project is conducted to explore one-dimensional (1D) simulation for a 4-cylinder gasoline engine. The simulation and computational development of modeling for the study are conducted by using the commercial Computational Fluid Dynamics (CFD) of AVL BOOST software. The engine model was developed corresponding to a Proton 1.6-litre CamPro 4-cylinder turbocharged gasoline engine including the real engine geometry and parameters. The engine model is based on 1D equation of the gas exchange process, progressive engine combustion process, isentropic compression and expansion, and accounting for the heat transfer as well as the frictional losses. The aim of the study is to predict the steady-state performance of the engine model at full and partload conditions from 1000 to 5000 rpm by using engine cycle simulation. In this study, three parameter tuning works have been performed, which are combustion model tuning, intake manifold temperature tuning and turbocharger’s scaling factor tuning. In addition, the comparison and validation were done for the output performance parameters based on the provided experimental data. Overall, the engine performance behavior have been observed to determine how accurate AVL BOOST software can evaluate engine performance compare to experiment conducted on the real engine. The most accurate validation of the engine performance parameters have been achieved by manifold absolute pressure (MAP) with 3.14% error. However, by comparing with experimental data, major discrepancy is noticeable on several engine performance parameters. From this study, the results showed that the engine model is able to simulate engine’s combustion process and produce reasonable prediction.

Effects of Pre-Turbocharger Turbine Water Injection on the Sustainable Performance of Spark Ignition Engine

Water injection strategy is considered a promising technique to improve the performance of boosted engine and reduce the NOx emission via the latent heat of water vaporization. Numerous research on water injection has been conducted on in-cylinder and intake port water injection. However, the water injection focusing on the spark ignition (SI) engine exhaust system is still lacking. This study proposed a pre-turbocharger turbine water injection (PTWI) concept to reduce the turbine inlet temperature. This was done so that the stoichiometric engine operation could be achieved at a medium–high load and engine speed without resorting to a fuel enrichment strategy to reduce the exhaust gas temperature. This study aims to investigate the effect of injecting water into the exhaust gas at the pre-turbine of a turbocharged spark ignition engine. This study experimented on a 1.3-L 4-cylinder turbocharged engine to collect engine data for computational fluid dynamics (CFD) baseline model validation. A one-dimensional engine model was then developed based on the 1.6-L 4-cylinder turbocharged engine experiment using AVL BOOST software. The CFD model was used to investigate the effects of water injection pressure, pipe diameter, and water injector location. The CFD results showed that a 50 mm connecting pipe with 4 bar of injection pressure gives the largest reduction in exhaust temperature. The CFD results were then applied to the one-dimensional engine model. The engine model simulation results showed that the fuel consumption could be reduced up to 13% at 4000 rpm during wide-open throttle and 75% engine load. The PTWI is a new approach, but this study has proved the potential of using water injection at the pre-turbine turbocharger to reduce the fuel consumption of a turbocharged SI engine.

Assessment of the impact of the number and the arrangement of cylinders of the KAMAZ disel engines on their fuel efficiency

Most of the natural aspirated truck diesel engines had an eight-cylinder V-twin (V8) configuration. Modern turbocharged diesel engines have a six-cylinder in-line configuration (L6), although some V8 diesel engines continue to be produced. A comparison was made of the performance of the KAMAZ-740 (V8) diesel engine with two turbochargers and KAMAZ-910 (L6) diesel engines with one turbocharger, having almost the same displacement with the same pattern of torque along the full load characteristic. The AVL BOOST software and experimental compressor and turbine maps were used. The factors influencing fuel efficiency were analyzed: indicated efficiency, friction and gas exchange losses, turbocharger efficiency. The L6 diesel engine had a uniform pressure pulsation in the exhaust manifold and at the turbine inlet. In the V8 diesel engine, the pulsations were uneven and had higher amplitude, which led to higher gas exchange losses and a decrease in turbine efficiency. The L6 diesel engine had a higher indicated efficiency but also higher friction losses. On average, the brake specific fuel consumption of the L6 diesel engine was by 5.5 % lower than that of the V8 diesel engine. Keywords V8 and P6 diesel engines; modeling in AVL BOOST; pressure pulsations in the exhaust system; turbocharger efficiency; friction and gas exchange losses

Fault location in a marine low speed two stroke diesel engine using the characteristic curves method

<abstract><p>When a malfunction occurs in a marine main engine system, the impact of the anomaly will propagate through the system, affecting the performance of all relevant components in the system. The phenomenon of fault propagation in the system caused by induced factors can interfere with fault localization, making the latter a difficult task to solve. This paper aims at showing how the "characteristic curves method" is able to properly locate malfunctions also when more malfunctions appear simultaneously. To this end, starting from the working principle of each component of a real marine diesel engine system, comprehensive and reasonable thermal performance parameters are chosen to describe their characteristic curves and include them in a one-dimensional thermodynamic model. In particular, the model of a low-speed two stroke MAN 6S50 MC-C8.1 diesel engine is built using the AVL Boost software and obtaining errors lower than 5% between simulated values and test bench data. The behavior of the engine is simulated considering eight multi-fault concomitant phenomena. On this basis, the fault diagnosis method proposed in this paper is verified. The results show that this diagnosis method can effectively isolate the fault propagation phenomenon in the system and quantify the additional irreversibility caused by the Induced factors. The fault diagnosis index proposed in this paper can quickly locate the abnormal components.</p></abstract>

Mechanical and Thermal Load Effect on Piston Crown of a Biogas Engine: A Simulation Approach

This paper presents the study results on stress and deformation of the piston crown of a biogas engine converted from a conventional diesel engine using dedicated software. The original diesel engine was modified to reduce the compression ratio to suit biogas fuel. The original engine's combustion chamber and compression ratio were changed by modifying the piston crown to a heron type. The parameters of in-cylinder pressure and temperature were determined by the thermodynamic simulation software AVL Boost. Research results show that the in-cylinder pressure decreased compared to diesel when using biogas fuel, but the temperature increased. The infinite element method-based software was used to simulate the effects of mechanical and thermal load on stress and deformation on the piston crown of the biogas engine. As modeling with maximum pressure and temperature, the maximum stress on the piston crown was 3.425x109 N/m2 and 4.224x109 N/m2 for diesel and biogas. However, the maximum deformation in the biogas case was lesser than diesel, 0.3037 and 0.4186 mm. The minimum safety factor was 0.1012 and 0.0891 for diesel and biogas models, respectively.

Combustion, Ecological, and Energetic Indicators for Mixtures of Hydrotreated Vegetable Oil (HVO) with Duck Fat Applied as Fuel in a Compression Ignition Engine

The aim of the present study was to investigate the effects of the application of hydrotreated vegetable oil (HVO) mixed with pure duck fat (F100) as fuel, replacing the conventional fossil diesel fuel (D100). The tests were performed using a four-stroke direct injection CI engine diesel engine. Six fuel samples were used: D100, HVO100, F100, as well as three HVO–fat mixtures F25, F50, and F75. To further study the main characteristics of fuel combustion, the AVL BOOST software (Burn program) was applied. The results of experimental studies showed that with the addition of pure fat to HVO, the ignition delay phase increased with an increase in the amount of heat released during the premix combustion phase and the pressure and temperature rise in the cylinder increased; however, the mentioned parameters were not higher as compared to diesel fuel. It was found that as the concentration of fat in the HVO–fat mixtures increases, the viscosity and density increases, while LHV was decreased, which thereby increases brake specific fuel consumption and slightly decreases brake thermal efficiency in comparison to diesel fuel. A decrease of CO2, HC, NOx emissions, and smoke was established for all HVO–fat mixtures as compared to diesel fuel at all loads; however; under low loads, CO emissions increased.

Performance Optimization and Knock Investigation of Marine Two-Stroke Pre-Mixed Dual-Fuel Engine Based on RSM and MOPSO

The two-stroke pre-mixed dual-fuel marine engine is prone to knocking at full load in gas mode, which affects the overall dynamic and economic performance of the engine. In this paper, the 7X82DF engine produced by Winterthur Gas & Diesel Ltd. (WinGD) was selected as the research object, aiming to investigate the effect of different parameters on engine power and knocking. Multi-objective optimizations were carried out. First, we used the one-dimensional simulation software AVL-BOOST to build the gas mode model of 7X82DF. Second, the pilot fuel start of combustion timing (SOC), the gas injection pressure, and the mass of diesel were taken as independent variables. The response surface methodology analysis of the independent variables was completed using the Design-Expert software and corresponding prediction model equations were generated. Finally, we took ringing intensity (RI) as the knock intensity evaluation index, combined with multi-objective particle swarm optimization (MOPSO) to optimize multiple-parameters to improve the overall performance and reduce combustion roughness of the engine. The optimization results showed that when the SOC was −8.36 °CA ATDC, the gas injection pressure was 20.00 bar, the mass of diesel was 14.96 g, the corresponding power was 22,668 kW, which increased by 0.68%, the brake-specific fuel consumption was 156.256 g/kWh, which was reduced by 3.58%, the RI was 4.4326 MW/m2, and the knock intensity decreased by 6.49%.

Study on the Cumulative Effects of Using a High-Efficiency Turbocharger and Biodiesel B20 Fuelling on Performance and Emissions of a Large Marine Diesel Engine

The marine sector represents probably the most powerful segment of international transport. Most ships use diesel engines for propulsion. Pollutant emission regulations with their continuous decline of acceptable limits put huge pressure on engine manufacturers. The use of low-quality fuels makes the marine sector a significant contributor to global pollution. The present study shows how turbocharger operating parameters and replacing diesel fuel with biodiesel B20 (20% oil and 80% diesel volumetric fractions) affect the performance, efficiency and pollutant emissions of a four-stroke diesel engine ALCO V16 251F for marine application. A combustion model developed with the AVL BOOST software was used to perform calculations using diesel fuel and biodiesel B20 for different turbocharger characteristics and injection timings. The model was calibrated against experimental data measured on a tested engine at the application site using diesel fuel and operating in a stationary condition of full load at 600, 700 and 800 rpm engine speeds. The results show that the cumulative effects of using an improved turbocharger associated with B20 fuelling under optimized injection timings could provide reductions of 45% for soot and 5% for NOx, while maintaining the same engine performance obtained with diesel fuel operation.

Numerical analysis of diesel injection strategies on emissions and performance in CH4/diesel powered RCCI diesel engine with high ratio EGR

In this study, the effects of intake port injection of methane and direct of injection diesel on emissions and the combustion of a light-duty RCCI engine were numerically researched. In this way, AVL Boost software was used for 1-dimensional simulation of the combustion process and emission estimation. Higher octane number methane gas was mixed with air from the intake port, while lower octane number diesel fuel was injected directly into the combustion chamber during the compression stroke. Methane gas was injected at a rate of 65% and diesel fuel at a rate of 35%. The diesel injected directly into the combustion chamber was sprayed at a rate of 5% between 0 and 35 °CA with 8 different injection timings after the main injection. In the model engine, 50% high EGR rate was applied in all combustion modes. The results showed that these parameters have significant effects on performance and emissions. The results in summary; NOx emission reduced at all engine speeds with delayed diesel post-injection timing. The maximum drop of NOx emission was 57.34% with Post15. Although the addition of methane slightly increased the soot emission, it was significantly reduced by the simultaneous addition of methane and application of post-injection strategies of diesel fuel. The soot emission was reduced by 58.85% with the Post35 injection strategy.

Simulation Study on the Effect of Biodiesel Ratio Derived from Waste Cooking Oil on Performance and Emissions of a Single Cylinder Diesel Engine

This paper presents a study on the effect of the biodiesel ratio on the performance and emissions of diesel engines. The research engine is a cylinder engine AVL-5402 that has been simulated using the software AVL-Boost.Simulated fuels include fossil diesel and biodiesel blended with the replacement rate from 0% to 50%, including B0, B10, B20, B30, B40, and B50, respectively, simulation mode at 1400 rev/min speed for maximum torque value of the engine, at the rate of 25%, 50%, and 75% load. Combustion characteristics, power, fuel consumption, and emissions are to be evaluated based on the proportions of blended biodiesel. The results show that there is a relationship between the proportion of blended biodiesel and the parameters of the engine. Specifically, as the ratio of biodiesel blend increases, peak pressure and rate of heat release decrease while peak temperature increases, the tendency to reduce engine power and increase fuel consumption increases. The emissions of CO and soot are reduced, while NOx is increased.

Simulation analysis and performance optimization of the combustion process of the opposed cam piston engine

Combining the structural features of cam engines and opposed engines, a kind of opposed cam piston engine is designed, in which a kind of variable sine curves family applied to the cam working surface. Based on the structure of this engine, a thermodynamic zero-dimensional model of the working cycle was established, and the accuracy of it was verified by the numerical simulation model utilizing the engine simulation software AVL BOOST. Based on the zero-dimensional model, the changes in the pressure, temperature, and quality of the working fluid in the cylinder under different cam profiles were calculated, and on this basis, the engine’s thermal efficiency, mechanical efficiency, overall machine efficiency, and power per liter were solved. Compared with common civil vehicle engines, OCPE has higher power per liter and has better economic performance and power performance.