Удосконалення характеристик кільцевого вхідного пристрою авіаційної силової установки з гвинтовентилятором

The article considers the method of improving the characteristics of the ring inlet device, taking into account the influence of the propeller of an aircraft power plant with a turboprop engine. It is shown that increasing the total pressure loss in the inlet device by 5% increases, approximately, the specific fuel consumption by 3% and reduces engine thrust by 6%, and uneven flow at the inlet to the engine is the cause of unstable compressor of the turboprop engine. It is proposed to improve the characteristics of the input device by modifying the shape of its shell and channel. Evaluation of the influence of the shape of the shell and the channel of the annular axial VP on its main aerodynamic characteristics, taking into account the non-uniformity of the flow on the fan in the calculated mode of operation of the SU is carried out by calculating the full pressure recovery factor. The object of the study is an annular axial input device in front of which is a coaxial fan turboprop fan. The process of modeling the influence of the shape of the shell and the channel on the recovery factor of total pressure, circular and radial non-uniformity of the flow through the input device is implemented in the software system of finite element analysis ANSYS CFX. Geometric models of coaxial screw fan, fairing and inlet device are built in ANSYS SpaceClaim and transferred using the built-in import function in ANSYS Workbench. Block-structured grid models of air propellers of the first and second rows of the fan in the amount of 1.9 million, fairing and inlet device, in the amount of 3.9 million, are built in the ANSYS TurboGrid environment. The standard Stern (Shear Stress Transport) Gamma Theta Transition was used to close the Navier-Stokes equation system. Based on the results of mathematical modeling of flow in coaxial fans and subsonic ring inlet device on the maximum cruising mode of the turboprop engine, the full pressure recovery factor is calculated and it is established that the most influential factor that increases its full pressure recovery factor.

Регулятор для двигателя МС-500 – разработка, испытания, сертификация

There are shown the features of the development process of the digital engine regulator RDTs-450M-S-500 for the MS-500V-02S turboprop engine as another modification in the family of regulators for engines of helicopter and aircraft (including unmanned aerial vehicles). These regulators are developed and serially produced by Element JSC since 2014 year, when the Appliance Design Approval of the aviation equipment component was received for RDTs-450M type. The creation of a new regulator is described as a modification of the basic design with the simultaneous refinement of a specially developed aircraft engine universal stand-imitator, which provides adjustment and verification of the parameters of the regulator. Information about the requirements differences for the rotor vibrations control compare the previous regulator modifications is given. It is shown that during the development process the need for a significant engine mathematical model correction was revealed. Element JSC specialists corrected this model originally provided by the engine developer Motor Sich JSC. The results of this correction performed based on experimental data are reflected. The results of using a new engine mathematical model, including the metering pump mathematical model, are presented. It is shown that the integration of a new mathematical model into a universal stand-imitator provided RDTs-450M-S-500 regulator adjustment and subsequent successful tests of RDTs-450M-S-500 as engine part, which confirmed the adequacy of the model. During this test, ensuring of the turbocharger rotor acceleration given level was confirmed too. There is provided here information on the regulator qualification in the Aviation Register of the Interstate Aviation Committee, based on the results of which Supplement to Applliance Design Approval for the component were received and information on the preparation for certification as part of the MC-500V-02S engine at the State Aviation Administration of Ukraine. It is mentioned that the experience of JSC "Element" specialists forces them to note the need to strengthen the methodological support of the aviation equipment components developers from the State Aviation Service.

Environmental assessment of entropy control in flight process

Purpose This study aims to examine exergy efficiency of engines and entropy performances at the flight process. In addition, the improvements that can be achieved in the system with the effective parametric controls of the engine have been evaluated in terms of both efficiency and entropy in the system. Design/methodology/approach According to the flight characteristics of the engine, the altitude-dependent irreversibilities and their environmental effects were discussed with two developed indicators, energy performance indicator (EPI) and sustainability indicator (SI). Findings According to the results of both indicators, the energy efficiency potential of the engine during the flight process was found to be 15.02%, while the fuel-based efficiency potential was 18.84%. Research limitations/implications It is limited by the flight process of a Turboprop engine. Practical implications The management tools and criteria of entropy are very difficult model studies. The study offers an evaluable approach based on two basic criteria developed for engines. Social implications In monitoring and review of entropy management related to fossil fuel technologies, key indicators developed can be used as benchmarks for managing emission sources Originality/value The two basic indicators developed can be used as monitoring measurement tools of sustainable energy and environmental performances for engines and applications.

Propeller Efficiency - Simple Methods

In order to produce thrust, the air needs to be accelerated by the propulsor (the propeller or the jet engine). The more the air gets accelerated from flight speed v = v_1 to exit speed v_4 (i.e. the higher v_4/v_1), the lower the efficiency. However, without accelerating the air, no power or thrust is produced. The efficiency depends on the non-dimensional thrust, called thrust loading, c_S, which is a function of aircraft speed. Disc loading k_P is calculated from power, P air density, rho and propeller disc area, A_S. k_P is independent of speed and as such a good characteristic parameter of a propeller. Together, this makes the propulsive efficiency a function of disc loading, k_P and flight speed, v. Further losses come from angular momentum. The efficiency calculated considering angular momentum in addition dependents on the ratio of forward speed, v and tip speed u (v/u). A constant speed propeller can run at a favorable speed for the piston or turboprop engine at a limited Mach number of the blade tips. At higher speeds, v and also v/u increases and hence required engine torque. This increases the angular momentum and reduces the efficiency. At low speeds, the ratio v_4/v_1 gets unfavorably high and the efficiency is low. At zero speed v_4/v_1 goes to infinity and the efficiency to zero. For an example calculation, optimum efficiencies were obtained at v/u between 3 and 5 depending on disc loading. Not considered is the limited lift-to-drag ratio (L/D) of the propeller blades and losses at blade tip (which could be accounted for by a performance factor between 0.85 and 0.9).