Engine Test Research Articles

Combined application of ANN prediction and RSM optimization of performance and emission parameters of a diesel engine using diesel-biodiesel-propanol fuel blends

In this study, an artificial neural network (ANN) was used to estimated the performance and exhaust emission parameters of a diesel engine running on diesel, biodiesel, and propanol fuel mixtures. In addition, the parameters estimated by ANN were tried determining the optimum operating parameter by using Response Surface Methodology (RSM). In the experimental study, propanol was added in 3 different ratios (5%, 10% and 20%) into 100% diesel, 80% diesel and 20% biodiesel fuel blends. In addition, engine tests, were made at 5 different engine speeds with 400 min-1 intervals between 1000 min-1 and 2600 min-1 revolutions at full load. In addition, HC (Hydrocarbon), CO (Carbon Monoxide), NOX (Nitrogen oxides) and Smoke emissions were measured during in the working. ANN model was developed for estimation of engine output parameters depending on fuel mixture ratios and engine speed. In the ANN results, the regression coefficients (R2) of the proposed model were found to be between 0.924 and 0.99. When the obtained ANN results were compared with the experimental results, it was seen that the maximum mean relative error (MRE) was 6.895%. It has been shown that the applied model can predict with a low error rate. The RSM results showed that the optimum operating parameters were 2034-min-1 engine speed, 74.667% diesel, 11.36% biodiesel and 15% propanol fuel mixture. In addition, in the validation tests of the model where the desirability was 0.7833%, the highest error rate was obtained as 7.37% as a result of NOX. As a result of the study, it was seen that RSM supported ANN is a good method for estimating diesel engine parameters working with diesel/biodiesel/propanol mixtures and determining optimum operating parameters.

Characteristics research of a low thrust rocket engine manufactured using additive SLM technology

The development and improvement of rocket and space technology are largely determined by the application of manufacturing technologies that enable the production of high-reliability products with energy efficiency, while simultaneously reducing material intensity and shortening the production cycle. Among these progressive technologies, additive technologies should be mentioned. The essence of these technologies lies in obtaining parts through layer-by-layer melting of material based on a computer 3D model of the product in a chamber of a specialized 3D printer equipped with a laser device. The application of additive technologies in rocket engine construction requires extensive scientific research and experimental work to confirm compliance with industry standards, rules, and mandatory certification at the state level. In accordance with the program of priority research at SibSU, in collaboration with the industrial partner “Polychrome” LLC a complex of experimental work is being carried out to test and refine the 3D printing modes of a demonstrator model of a low thrust rocket engine (LTRE). The design of the LTRE, operating on environmentally friendly gaseous fuel components, has been developed and adapted for 3D printing on the ASTRA 420 printer. The parameters and characteristics of the printer are considered, and the sequence of experimental work on selecting printing modes for the engine chamber housing and mixing head is outlined. The fundamental possibility of adjusting the modes of laser material melting and forming of the part has been established. The main technological stages of post-printing processing of LTRE chamber parts are presented. A description of the equipment for heat treatment and electrochemical polishing of parts is provided. The sequence of material structure research is outlined, and the results of metallographic and X-ray analysis of the internal state of the metal are presented. The importance of stand tests of rocket engines in the development of innovative design solutions and the implementation of innovative production technologies is demonstrated. A description and composition of the testing stand system at SibSU are presented. The results of stand firing tests indicate the fundamental possibility of manufacturing LTRE using selective laser melting of heat-resistant alloy.

Effects of dual injection strategies on combustion, heat-work conversion process and emissions of a spark ignition engine fuelled with E20 blends

In this paper, the combustion, heat-work conversion process and emission characteristic at high compression ratio for the spark ignition engine fuelled with E20 (20 % ethanol, 80 % gasoline) fuel were investigated under ultra-lean burn conditions. Specifically, the direct injection (DI) mode combined with port fuel injection (PFI) mode strategy was used in the experiments. In addition, the dual injection strategies were comprehensively investigated by using different fuel injection masses and injection timing. The results indicated that using optimal injection timing and reasonable injection masses can improve heat-work conversion efficiency and combustion efficiency, combustion stability in the test engine. Furthermore, under the lean combustion model, using earlier injection timing could not only inhibit the soot production, but also decrease the nitrogen oxides formation. Compared to the equivalence ratio at 0.82 and DI injection timing at 120 °CA bTDC, soot and NOX emissions were respectively reduced by 14.93 %–26.6 % and 39.84 %–73.56 % under the equivalence ratio at 0.685 and DI injection timing at 180 °CA bTDC. This study provides an optimization direction for the application of ethanol-gasoline blends in the internal combustion engine (ICE) engines for high efficiency and clean combustion.

Feasibility of using BeO rods as secondary neutron sources in the long-life fuel cycle high-temperature gas-cooled reactor

External sources of neutron provide stable and sufficient neutron for initial startup of a nuclear reactor. They also provide signals for neutron detectors to monitor the safety of reactor during shutdown. In the high temperature engineering test reactor (HTTR), 252Cf is used as the external neutron source. However, the 252Cf sources must be renewed every approximately 7 years because of its relatively short half-life of 2.6 years. The renewal of 252Cf sources requires a high cost and a very complicated procedure. This study investigated the feasibility of using BeO rods as the secondary neutron sources to avoid renewing the 252Cf neutron sources periodically. The BeO rods could exist in the reactor for a long time so that if the reactor operates long enough, the neutron flux at the wide-range monitoring detectors remains more than 10n.s−1.cm−2 even if the reactor is shutdown for as long as 5 years. The results of this study indicated that using BeO rods as the secondary neutron sources would be an attractive option for the future HTGR design with a long-life fuel cycle.

Feasibility Study of Exhaust Energy Recovery System for Mobile Carbon Capture Operations in Commercial Engines through 1D Simulation

The global proportion of eco-friendly vehicles continues to increase; however, regarding hybrid vehicles, the vehicle powertrains in most countries include internal combustion engines. Therefore, research on reducing the carbon emissions from internal combustion engines must be conducted. Carbon capture technology must be developed for e-fuel, which has recently attracted attention, to achieve carbon neutrality. In this study, a turbo compound system capable of recovering waste exhaust gas energy was selected as the most appropriate energy supply system to operate a mobile carbon capture system. The feasibility was reviewed by analyzing the turbo compound speed, pressure drop, power generation, etc., using a one-dimensional simulation method. The maximum power generation of the configured turbo compound system was approximately 9 kW, and approximately 1–3 kW of energy could be recovered under medium speed and load conditions, which are the optimal operating conditions for a test engine with the displacement of a 4 L.

Determination of the Caving Zone and Fracture Zone Heights by Using the LK-Means Algorithm

The caving zone and fracture zone frequently appear after coal excavation. However, the caving zone and fracture zone can hardly be obtained with an empirical equation. Therefore, identifying a proper method to determine the caving zone and fracture zone is critically important to engineering practice. In this paper, Universal Distinct Element Code numerical simulations were conducted. Furthermore, the LK-means algorithm was used to determine the caving zone and fracture zone heights. To verify the validity of the proposed method, two engineering case studies were used. It could be found that the height calculated by the proposed method agrees well with that determined in engineering tests. Hence, the proposed method can be used in engineering practice.

Investigation on formaldehyde generation characteristics and influencing factors of PODE/methanol dual-fuel combustion mode.

Polyoxymethylene dimethyl ether (PODE) and methanol are important low-carbon substitutable fuels for reducing carbon emissions in internal combustion engines. In the research, the impacts of methanol ratio, injection timing, and intake temperature on HCHO generation and emission were investigated using both engine tests and numerical simulations. Results suggest that an increase in methanol ratio suppresses auto-ignition tendency of PODE, leading to the increase of ignition delay period, pressure peak, and heat release rate peak inside the cylinder. The decrease in in-cylinder combustion temperature contributes to an increase in HCHO emission due to partial oxidation of methanol in the cylinder and exhaust pipe. While the injection timing is gradually postponed from -10 °CA ATDC to 2 °CA ATDC, in-cylinder high-temperature area decreases, the quantity of unburned methanol increases, but part of HCHO is converted to HCO due to H radical influence, resulting in 72% increased HCHO emission. With the increment of intake temperature, the oxidation and decomposition of in-cylinder methanol accelerate, leading to an improvement in combustion stability, more uniform temperature distribution, and a decrease in unburned methanol, which results in lower HCHO emission. When the intake temperature is rose from 30 to 60 °C, HCHO emission decreases by 11.2%.

Effects of nanoadditives on the performance and emissions of rapeseed biodiesel in an insulated piston diesel engine.

Energy consumption and management have emerged as crucial production functions because of the high cost of energy. Since the total consumption of fossil fuels like diesel has increased proportionally to the expansion in demand for power generation, industry, and transportation services, researchers have long been interested in constructing a more energy-efficient engine. With its improved efficiency, reduced fuel consumption, and fewer emissions, the application of nano-coating technology to engine components has become more popular in recent years. This study involved the application of a thermal barrier coating (TBC) using zirconia on the test engine piston. The aim of this research is to examine the impact of aluminium oxide nano-additives in rapeseed biodiesel blends on the performance of a diesel engine with a thermal barrier-coated piston. The four test fuels were prepared using 20% and 40% blends of rapeseed biodiesel with and without the addition of aluminium oxide at 25 ppm and 50 ppm. The full factorial design methodology was employed to examine the influential factors, specifically the rapeseed blend ratio and aluminium oxide concentration, in order to enhance performance and reduce emissions. The blends of RSB20AO25 and RSB20AO50 showed significant results on energy consumption and emissions. The RSB20AO50 blend performed with a 5.4% increase in brake thermal efficiency and a 6.5% reduction in fuel consumption compared with standard diesel. Similarly, blends of RSB20AO25 and RSB20AO50 show 6% and 11% reductions in carbon monoxide and 5.2% and 9.5% reductions in hydrocarbon emissions.

Numerical study of the flow and heat transfer characteristics in a scale model of the vessel cooling system for the HTTR

The reactor cavity cooling system (RCCS) is a passive reactor safety system commonly present in the designs of High-Temperature Gas-cooled Reactors (HTGR) that removes heat from the reactor pressure vessel by means of natural convection and radiation. It is one of the factors responsible for ensuring that the reactor does not melt down under any plausible accident scenario. For the simulation of accident scenarios, which are transient phenomena unfolding over a span of up to several days, intermediate fidelity methods and system codes must be employed to limit the models’ execution time. These models can quantify radiation heat transfer well, but heat transfer caused by natural convection must be quantified with the use of correlations for the heat transfer coefficient. It is difficult to obtain reliable correlations for HTGR RCCS heat transfer coefficients experimentally due to such a system’s size. They could, however, be obtained from high-fidelity steady-state simulations of RCCSs. The Rayleigh number in RCCSs is too high for using a Direct Numerical Simulation (DNS) technique; thus, a Reynolds-Averaged Navier–Stokes (RANS) approach must be employed. There are many RANS models, each performing best under different geometry and fluid flow conditions. To find the most suitable one for simulating an RCCS, the RANS models need to be validated. This work benchmarks various RANS models against three experiments performed on the HTTR RCCS Mockup by the Japanese Atomic Energy Agency (JAEA) in 1993. This facility is a 1/6 scale model of a vessel cooling system (VCS) for the High Temperature Engineering Test Reactor (HTTR), which is operated by JAEA. Multiple RANS models were evaluated on a simplified 2d-axisymmetric geometry. They were found to reproduce the experimental temperature profiles with errors of up to 22% for the lowest temperature benchmark and 15% for the higher temperature benchmarks. The results highlight that the pragmatic turbulence models need to be validated for high Rayleigh natural convection-driven flows and improved accordingly, more publicly available experimental data of RCCS resembling experiments is needed and indicate that a 2d-axisymmetric geometry approximation is likely insufficient to capture all the relevant phenomena in RCCS simulations.

Load study and structural analysis for CFETR divertor OVT

China Fusion Engineering Test Reactor (CFETR) is an important device for studying fusion reactor engineering in China. The Outer Vertical Target (OVT) are high heat load components of the divertors and work in a strong electromagnetic field, so they need sufficient heat removal capability and structural strength. In addition, due to activation of neutrons on materials, the OVT also needs to meet the requirements of Remote Handling (RH) maintenance. CFETR puts forward the concept of hybrid divertor-blanket, which cancels the cassette and adopts a separate structure. The lower part of the divertor is occupied by the breeding blanket, and the divertor target is fixed on the breeding blanket, to improve the RH maintenance efficiency and Tritium Breeding Ratio (TBR). In previous work, the structural design and thermal-hydraulic analysis of the OVT were completed. In this paper, load study and structural analysis was carried out to verify the structural strength of the OVT under experimental test conditions (including liquid pressure, nitrogen baking), normal operation conditions (including the impact of thermal stress under thermal load, gravity, working pressure, etc.) and extreme event conditions (Vertical Displacement Event (VDE) or Major Disruption (MD) event, including the impact of thermal stress under thermal load, gravity, working pressure, electromagnetic load, etc.). The results show that the OVT meets the requirements of heat removal and strength, and effectively promote the processing and manufacturing of the prototype of the OVT.

Some developments in the field of non‐destructive testing ‐ new devices and techniques, industrial training and academic education

AbstractNon‐destructive testing in civil engineering is a fast‐emerging field. This includes not only new devices, sensors, and techniques for the inspection of materials, components, and structures contributing to building information modeling (BIM) but also efficient concepts for structural health monitoring in the frame of digital twins. The paper highlights some of these new developments and examples for applications covering the design of new construction materials, quality control during construction, contributions to predictive maintenance, and finally the rehabilitation and repair of structures.The new demands and techniques require new training concepts for the qualification of experts for the construction industry but also well‐structured courses for the academic education of students. Some new standards for training and education will be introduced. This paves the way for modern, efficient, and reliable applications of non‐destructive testing and structural health methods.

AP assembled on ultrafine aluminum particle and its application to NEPE propellant

Coating modification is an important way to enhance the reactivity of aluminum powder. In this paper, ammonium perchlorate and aluminum powder were assembled into energetic microunits by liquid deposition method. Spherical particles with AP as shell and ultrafine aluminum powder as the core (Al@AP) were gained. The micromorphology results show that the coated particles are about 5 μm, and the coating layer is evenly distributed on the outer surface of aluminum powder, indicating a complete coating. The energetic microunits were implanted into the nitrate ester plasticizing adhesive system (NEPE) as solid phase fillers. The effect of filler on the rheological properties, safety, mechanical properties, thermal reaction and energy properties of the system was analyzed by comparing with the raw aluminum filler. The test results show that the rheological properties, mechanical properties and pressure index of NEPE containing system Al@AP meets the requirements of solid propellant charging. Compared with Al based propellant, the mechanical sensitivity and thermal sensitivity are decreased, the safety is better, and the explosion heat of the propellant is increased by 7.8%. The engine test shows that the specific impulse is increased by 1.2 s. Al@AP can improve the energy output and safety of NEPE propellant, and has potential application prospects in high-energy propellants.

Determination of the Reduced Heat Transfer Resistance of Opaque Sections of Facade Translucent Structures

The thermal engineering characteristics of the facade translucent structures (FTS) are considered. The analysis of the results of thermal engineering tests of structures in the climate chamber for various manufacturers has been carried out. As a result of comparing the test results with the calculated data of the reduced resistance to heat transfer, their significant discrepancy was revealed. A method has been developed for determining the coefficient of linear inhomogeneity of the opaque part of the FTS based on laboratory tests with different fillings for different outdoor temperatures. Based on the coefficients of linear inhomogeneity of the opaque part of the CFS determined in laboratory conditions, it is proposed to determine reliable values of their reduced resistance to heat transfer for different design options.

Turbocompound energy recovery option on a turbocharged diesel engine

The transportation sector is living a transition era in which hybrid and electrified vehicles are replacing conventional vehicles, based on internal combustion engines. This is pushed by the recognized need for reducing fuel consumption and tailpipe emissions, considering primary pollutants and carbon dioxide as a greenhouse gas. In the transition path, hybridization and partial electrification of the powertrain play a crucial role. In this regard, the need for on-board electrical energy storage and utilization is increasing significantly and the possibility to recover wasted energy and convert it into electrical form is mandatory. This is especially true for commercial and heavy-duty vehicles, where full electrification is more difficult to be implemented. Waste Heat Recovery (WHR) has therefore become so important for vehicles, not only to directly reduce fuel consumption and related emissions but also to improve the feasibility of a generation of vehicles with a higher degree of hybridization that considers, for example, the electrification of auxiliaries following the so-called auxiliaries-on-demand management. Wasted heat refers mainly to exhaust heat from gases, where about one third of the fuel energy is disposed of. Among the various systems for WHR, engine turbo-compounding is approaching a mature technology. This technological option makes use of an additional turbine on the exhaust line of the engine, downstream of the turbocharging one, which converts the residual gas enthalpy into mechanical form. In this paper, the F1C Iveco 3.0 L turbocharged diesel engine is considered for verifying the performances of a turbo-compounding system. The engine was mounted on a dynamic engine test bench. In particular, the interactions with the original engine produced on the exhaust line were studied. Backpressure effects on the engine introduced by turbo-compounding were evaluated reversed in terms of extra fuel consumption. Moreover, the new equilibrium of the turbocharger was assessed and the related modifications to the engine were measured considering that the turbocharger has a control strategy based on the so-called Variable Geometry Turbine (VGT), via the modification of the Inlet Guide Vanes (IGV). The presence of a secondary turbine for WHR opens to a wider possibility of actuating the IGV and, so, the possibility to optimize the recovery considering the integrated system and all its degrees of freedom.

Optimized Design of C8051F040 SOC Based Automotive Engine Tester

Automotive engine tester is an important instrumentation for performance testing and fault diagnosis of automotive engines. How to make real-time effective and fast engine testing has become a key technology for automotive engine testing. This paper further optimizes the C8051F040 SOC's automotive engine tester based on the use of a cost-effective C8051F040 system-on-chip as the core, supplemented by relevant sensor sets and other functional components, to achieve the design requirements of a low-cost, high-performance instrument. The overall performance of the system is superior and versatile through prototype testing.

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.

A framework to simulate and to auralize the sound emitted by aircraft engines

In civil aviation, the well-established Effective Perceived Noise Level (EPNL) has remained, so far, a simple but reliable psycho-acoustic metric, representing the backbone of noise regulation politics and leading to quieter aircraft turbofan engines. However, the recent changes induced by further acoustic optimization of engines, or the introduction of innovative designs, suggest that a more refined assessment than the sole EPNL metric is needed, which is based on sound auralization. The paper presents a framework of simulation tools that are currently being developed at the DLR Engine Acoustics Department with the goal of assessing novel designs at a very early development stage. This framework allows to simulate acoustically an engine flyover and to produce audible signals as perceived by a virtual observer standing on the ground. The source calculation is performed by the tool PropNoise and relies on analytical physics-based models for the fan noise sources, and Stone's semi-empirical jet noise model. The subsequent tool VIOLIN simulates the propagation of sound through the atmosphere and the ground reflection effects. Finally, the spectrograms of the broadband and tonal noise components are converted to audible sound by the auralization tool CORAL. The procedure is applied to a realistic engine test case and compared with experimentally recorded sound.

Outdoor engine test using acoustic liners combined with Fine-Perforated-Film

Resonant-type liner panels are one the primary countermeasures for the fan noise of aircraft engines, though the noise reduction performances of the liners are known to be tolerated by the flow streaming on the liner surface. Therefore, suppressing the effect of the flow on the liners is greatly important for larger noise reduction. In this study, a liner panel with a special surface structure was manufactured and applied to an outdoor test using a small turbofan engine, DGEN 380. The surface structure consisted of a special thin film, Fine-Perforated-Film (FPF), and a gap. The gap was fixed between the FPF and liner surface. In addition, a typical resonant-type liner and a hard wall were used for comparison, to investigate the effect of the structure. During the test, the samples were installed to the exhaust bypass duct of the DGEN 380 engine. The acoustic pressure was measured with a far field microphone array. Analysis and comparison of the results showed that the new structure suppressed the effect of the grazing flow and caused a larger amount of noise reduction, compared to the typical liner sample.

Engine Performance Testing and Fuel Consumption of Unmanned Aerial Vehicle with Octane Rating Variations

Unmanned aerial vehicles or often known as Drone / UAV are used for various missions, some of which are for aerial photography, monitoring, load testing, spraying fertilizers and so on. The performance of unmanned aircraft is supported by several aspects, one of which is the propulsion or engine of the aircraft. The Aeronautical Technology Research Center, BRIN, Indonesia has several series of unmanned aerial vehicles used for several missions. To support the missions that must be taken by unmanned aircraft, engine performance is one of the important factors for carrying out missions. In this study, engine testing will be carried out to see the performance of the engine by varying the octane rating of the fuel used. This test used an LSU-04 aircraft engine with a 3W-110i B2 engine type with a capacity of 110 cc and a propeller size of 26x8. Engine tests were carried out using 3 types of fuel with octane ratings of 92, 95 and 98. The data taken is engine speed data (rpm), thrust data and fuel consumption data. Tests and measurements were carried out at the highest rpm value of 6000 rpm and the test was carried out for 1 hour. From the test results, the results were obtained that the performance of the engine that has the largest thrust value is the one that uses fuel with an octane rating of 92, namely with a thrust value of 14.13 kgf, while the thrust value for fuel with an octane rating of 95 is 13.35 kgf, and the thrust produced in fuel with an octane rating of 98 is 13.06 kgf. Then from the results of measuring fuel consumption, the most economical value is an engine that uses fuel with an octane rating of 98, which consumes 1007 ml of fuel, while for fuel consumption with an octane value of 95 of 1028 ml and for an octane value of 92 of 1061 ml.Keywords: UAV, 3W-110i B2 Engine, 92 Octane, 95 Octane, 98 Octane, Engine Performance

Influence of water‐methanol injection and turbocharging on the performance of a hydrogen‐fueled spark ignition engine

AbstractThis article presents a study that compares the performance and emission characteristics of a four‐stroke, four‐cylinder spark ignition (SI) engine fueled by gasoline and neat hydrogen. The engine was equipped with turbocharging to optimize ignition timing for power boosting and vaporized water–methanol injection to reduce emissions. Engine tests were conducted at speeds ranging from 2000 to 6000 rpm, with a fixed intake pressure and varying quantities of hydrogen and spark advance timings. The study compared the results of non‐turbocharged and turbocharged engines with water–methanol injection in terms of combustion, performance, and emissions. The findings showed that the turbocharged water–methanol hydrogen operation had a higher brake thermal efficiency (BTE) than its counterpart, while the brake power of the hydrogen engine operation increased with turbocharging but slightly decreased with water–methanol injection. Additionally, volumetric efficiency improved by 7% for turbocharged and 4% for water‐injected hydrogen engine operation compared to the counterpart. The cylinder pressure for turbocharging with water–methanol operation yielded 16.32% higher compared with counterpart gasoline engine operation. Finally, nitrogen oxides (NOx) emissions were reduced with turbocharging and water–methanol injection compared to the counterpart non‐turbocharged hydrogen engine operation.