Dynamic Modeling and Full-Process Simulation of the Core Engine Test Rig Main Test System

As a virtual digital model that can reflect physical entities or systems, digital twins are revolutionizing industry. The first prerequisite for the construction of digital twins is the establishment of high-precision and complex entities or system models. A 47-components numerical system is established for the core engine test rig main test system by using the finite volume modularization modeling method. A comprehensive solution to the system-level valve-spool/orifice throttling modeling, the key issue of the fluid pipeline system modeling, is presented, and the algorithms of throttling and mixing are deepened and expanded. The full-process simulation study on two tests of normal-temperature 1400 s and low-temperature 1240 s shows that the combined regulation of five regulator valves and the change of cold source directly decide dynamic change of the system in each stage; the simulation reveals the phenomena such as the gas cylinder cooling with deflation, the air cooling when expanding from main pipeline to two branch pipelines, shunting flow by branch pipeline, and the cold and hot gases mixing; the overall variation trends of the simulation curves are consistent with those of all the experimental curves of the test rig normal-temperature/low-temperature air supply lines, exhaust bypass, and engine main line in two operating conditions, and the maximum error between simulation curves and test curves of pressure, total pressure, and total temperature is less than 12%. The numerical system can be used for the construction of virtual models of digital twins, and the modeling method provides a feasible solution to the key technology of digital twins.

Investigating the Performance of a Laboratory Dynamometer for a Three-wheeler Engine Test Rig

The dynamometer is to mimics driving condition in an indoor controlled condition measuring engine output parameters like speed, torque, power, combustion conditions and exhaust compositions. However, the complexity and dynamics involved in the making of this instrument makes it unaffordable for student research except it is funded. This work reports an innovative method adopted to measure a three-wheeler engine output parameters. An automobile vehicle dynamo was adopted which requires low speed and outputs high torque. Driving conditions were incorporated as brakes for the dynamo which mimics the driving terrains experienced by the engine. A data acquisition unit capable of converting the electrical signals into readable values on a screen and a user interface on a PC completed the dynamometer development. The dynamometer was then calibrated against known output values of speed and torque. A three-wheeler engine was mounted on a test rig and the dynamometer was used to measure output speed, torque and energy dissipated. A Bajaj engine was mounted and the engine output tested for two types of transmission of manual and continuously variable transmission. The measured output from the engine showed that the developed dynamometer performed effectively and therefore be adopted for use for student research in this area. Keywords— dynamometer, load, speed, terrain, torque.

Effect of Nitromethane and Jatropha Biodiesel on the Combustion, Performance and Emission Characteristics of Diesel Engine

The experimental work reported has been carried out in two parts; Jatropha biodiesel production and engine test. The engine test has been carried out on a direct injection, single-cylinder, water-cooled stationary diesel engine. Several diesel fuel blends which contain 10% and 20% by volume of JBD and 1% and 3% nitromethane were prepared. The effects of these blends on the combustion, performance, and emission characteristics of diesel engine were studied. The tests were performed under constant speed and varying load conditions without altering injection timing. A maximum increase of 11.73%, 3.2 % and 7.68 % in the brake thermal efficiency, the brake specific fuel consumption and exhaust gas temperature were achieved respectively for 20% Jatropha biodiesel and 3% nitromethane at full engine load. Compared to the pure diesel operation, the peak in-cylinder pressure of blended fuels was lower at the full load conditions. Also, the maximum net heat release rate of blended fuels was lower than that of diesel at all loading conditions. In regards to the engine emissions, the results showed that the blended fuels reduced carbon monoxide at 18.6–28.9% and unburned hydrocarbon of 7.5-24.2%, while increased the emission of nitrogen oxides at 6.9–14.3% and carbon dioxide at 4.3-10.5%.

Design and evaluation of an engine-in-the-loop environment for developing plug-in hybrid electric vehicle operating strategies at conventional test benches

Due to a large number of degrees of freedom and connected powertrain functionalities, the development of operating strategies for plug-in hybrid electric vehicles is an especially complex task. Besides optimizations of drivability, noise, vibrations and harshness as well as energy efficiency, the main challenge lies in ensuring emissions conformity. For this purpose, test vehicles are typically applied to achieve a realistic test and validation environment. However, operating strategy calibration using test vehicles has the drawbacks, that (i) it is very time consuming and cost intensive, (ii) it can only be conducted in late development phases and (iii) cannot be applied to reproducing driving loads for a valid comparison. To overcome these issues, this paper presents a consistent engine-in-the-loop approach combining real engine hardware and multiple software elements to represent PHEV behavior at the engine test bench. Thereby, an environment is created, which allows for realistic, flexible, cost efficient and reproducible testing. The effectiveness of the presented framework is evaluated by comparing relevant on-road measurements with their reproduction at the engine test bench. The results show that the vehicle on-road behavior can be replicated using the described testing environment. Particularly engine start/stop behavior and load levels—the core functionalities for operating strategy calibration—are matched. The proven level of realism in powertrain behavior enables further use cases beyond on-road measurement reproduction, i.e. varying individual component properties and observing real-world consequences at the test bench without the need for vehicle tests.

Influence of inlet swirl on pattern factor and pressure loss in an aero engine combustor

The effect of compressor exit swirl angle (θsw) at the intake of an aero engine combustor on the exit temperature non-uniformity (pattern factor) and combustor total pressure loss is investigated. Experiments are conducted in the engine test rig, measuring the gas temperature and pressure at the inlet and exit planes of the combustor. These parameters are measured at distinct locations along the circumferential and radial directions in the engine test facility. Simulations are carried out using RANS based turbulence modeling and reacting flow approach with Ansys CFX commercial code. The predicted results are validated with experimental data at 5° swirl angle. The swirl angle at the combustor intake is further varied from 0° to 15° and 4 cases (0°, 5°, 10° and 15°) has been considered to predict the effect on the combustor pattern factor and pressure loss. The changes in the flow structure inside the combustion chamber for all these 4 cases are reported in detail. The pattern factor varies from 0.34 to 0.49 as swirl angle changes from 0° to 15°. The lowest pattern factor of 0.34 occurs at 10° swirl angle. However a linear increase in combustor total pressure loss from 5.85% to 6.53% is predicted with the change in swirl angle from 0° to 15°.

Manufacturing Engine Test Bed Dle-55cc Single Cylinder Petrol

The engine test bed is a tool used for testing in the development of new aircraft when it is installed into the aircraft to determine the capabilities of each engine. This engine test bed research aims to meet the needs of the learning process in supporting the practicum. By determining the geometry, modeling, material selection, manufacture, and testing of the engine test bed it will be known that the engine performance is good before use. The method used is a practical and analytical method to analyze the data that has been obtained from the test. The object of research used in this study is a dle-55cc engine. based on the results of testing the results of the thrust that compares with the static value of the thrust calculator, the average difference is obtained. From the results of the comparison of errors on the test equipment, the 22×8 propeller (4.5cm chord) obtained an average error of 4.178%. While the propeller 22×8 (chord 5cm) the error generated is 3.719% and from the value of fuel consumption obtained it produces 588,600-20,708 (N/kW.hr) this shows a good level of decline, so the engine used is more efficient in its use. From the test results, it can be said that the engine test bed has accuracy and can produce good engine performance to be used as a testing and other learning tool.