جستجوی مقالات مرتبط با کلیدواژه "موتور توربینی" در نشریات گروه "مکانیک"

Due to the complexity of the processes governing the flow in the gas turbine, it is necessary to perform experimental tests to ensure the performance, but creating the conditions governing the components in the operational conditions is very complex. most of the combustion chamber tests are performed in atmospheric conditions and then the results are generalized to the operational conditions. This work, along with the lack of test stands with real operational conditions, has been developed based on the fact that most of the processes governing the behavior of the chamber have not undergone significant changes with the change of operating pressure, and especially if the shape of the flame does not change, it is possible to study the behavior of the chamber even at low pressure. In the present research, this issue has been numerically investigated for a real combustion chamber and it has been observed that changes are characterized by increasing pressure. Also, NOx pollutant increases at higher pressures. The overall flow structures were not affected by the pressure increase, but the pressure loss rate increased. The current results show that in the desired combustion chamber, the atmospheric test can provide acceptable results and can be generalized to high pressure conditions.

The performance of the propulsion system and the engine, known as the heart of the aircraft, is highly dependent on subsystems, such as the engine control subsystem.Today, most modern military and civil aircraft use turbine engines to generate thrust. The engine control system is one of the most challenging aircraft control systems that has undergone significant changes and improvements over time. The goal of any engine control system is to provide maximum performance in each flight conditions. With the increase in requirements and the development of technology in propulsion systems, digital electronic engine control and full authority digital engine (electronics) control have replaced hydromechanical control. The purpose of this study is to present the development process of turbine engine control system historically and to find new methods of engine control. Depending on the complexity of the aircraft propulsion system engine, the engine control approach will be determined and designed.

Buckling is one of the main causes of breakdown in thin wall structures, so the possibility of buckling should always be considered in design and analysis. In this research, instability of a rotating drum in a turbine engine with several rows of blades attached to its external environment is analyzed. The rotary drum structure is a thin-walled conical structure that is subjected to a variety of mechanical and thermal loads. The rotary drum is modeled as a conical structure and analyzed in the Abaqus finite element software and verified by theoretical relations. The stresses applied to the structure are determined, and the buckling coefficients, or eigenvalues, are extracted, and the stability of the drum structure and its associated factors are discussed. The results of the analysis show that the effect of thermal loading on the buckling of the drum structure is greater than external pressure loadings. In the cone drum the critical stress is 710 MPa and the maximum working stress is 660 MPa.