جستجوی مقالات مرتبط با کلیدواژه "بستر آزمون" در نشریات گروه "مکانیک"

In this article, the effect of using phase change materials to improve heat transfer in power distribution transformers has been investigated experimentally. To enhance the cooling of the transformer, a new method has been proposed, which involves adding paraffin inside aluminium containers that are sealed to the transformer oil. The test setup includes an electric transformer filled with transformer oil, two electrical heaters, a power regulator, a thermal camera, oil insulation measuring device, and temperature sensors placed at various locations. The experimental results demonstrated that the addition of phase change materials to the electronic transformer oil led to a decrease in the temperature of the transformer, particularly in summer weather conditions. Additionally, the mean temperature of the transformer oil was reduced from 46.7 to 42.5 degrees Celsius by adding 8 kg of paraffin. However, it was observed that when the temperature increases suddenly and rapidly within an hour, these materials are ineffective in dissipating the heat and reducing the temperature of the transformers. Additionally, the research examines the impact of continuous and high-temperature increases on the oil electrical insulation. The results revealed that using phase change materials increased the voltage that the oil could withstand as an electrical insulator from 56.8 kV to 61 kV.

Changes in altitude from the sea level have a significant effect on the performance of the internal combustion engine. Turbochargers can be used to maintain engine power by changing the height. In order to test the combination of turbochargers under the conditions of high altitude, the pressure and temperature should be created, which is possible by placing all the test set in the altitude simulator chamber, or at least the conditions of inlet and outlet must be controlled and the pressure and temperature associated with it altitude made. Creating these conditions is difficult to control. The purpose of this paper is to provide a simpler and more cost-effective way to create a r turbocharger test bed on an internal combustion engine in altitude conditions. In this paper, one-dimensional simulation engine is engineered and compared with the motor test results. Using a compression ratio, mass flow rate and corrected distances obtained from simulation, a simple method for testing the required pressure ratio at the desired height is presented. This preliminary design can specify the scope of turbocharger control overhead and reduce the cost and time of operational testing of the bird's device for extracting control overflow.The simulation of the target engine in the research and comparing it with the experimental results at different periods shows a maximum simulation error of 10%. This research is the applicable over a wide range of altitudes. The turbocharged motor is capable of maintaining 90% power up to a height of more than 12.2 km.

The calibration of modern internal combustion engines is complex and requires a lot of time and cost on the test bench. A large number of calibration parameters and a tradeoff between fuel consumption and emissions make calibration a complex multi-objective optimization problem. The purpose of this article is the development of calibration and model-based optimization techniques for internal combustion engines to reduce calibration time and cost and improve optimization accuracy. This paper focuses on empirical modeling of engines and optimization concerning emissions standards and fuel consumption. To identify the combustion models, a modeling toolbox is developed with an intelligent identification method. To optimize the data collection, the design of experiment methods is reviewed and appropriate methods are selected to collect information with the minimum data from all over the design space. Finally, a study is performed on the EF7 engine in the test room of IPCO and it is shown that the number of experimental data is reduced from 5500 data to 1500 data with the help of the design of experiment by Sobol method and modeling by a deep neural network. so, the virtual engine can replace the real engine in the calibration process.