scholarly journals Моделювання течії в дворядному вентиляторі турбореактивного двоконтурного двигуна

2021 ◽  
pp. 19-24
Author(s):  
Антон Валерьевич Балалаев ◽  
Екатерина Викторовна Балалаева ◽  
Юрий Юрьевич Терещенко
Keyword(s):  
Boundary Layer ◽  
Aircraft Engine ◽  
Aerodynamic Characteristics ◽  
Rate Function ◽  
Rotor Speed ◽  
Dynamic Flow ◽  
Single Row ◽  
Gas Dynamic ◽  
Bypass Ratio ◽  
Range Of Values

Modern trends in the global aircraft industry are prompting aircraft engine engineers to create and develop various methods to improve the aerodynamic characteristics of turbomachines. The urgent need to improve the efficiency of new generation engines leads to a rapid increase in the bypass ratio of engines, which requires the development of fans with large diametrical dimensions and high aerodynamic perfection. Boundary layer control in turbomachines using tandem blade rows is one of the most promising ways to improve the aerodynamic characteristics of aircraft engine fans with a high bypass ratio. The work aims to evaluate the aerodynamic characteristics of a fan with a tandem impeller for a turbofan engine. Two fan impellers were investigated: a single-row and an equivalent tandem-row (the equivalence was ensured by the equality of the structural angles of the flow inlet and outlet and the equality of the chord of the profiles). The blade row consisted of 33 blades, the tip diameter at the inlet to the impeller was 2.37 m, the hub diameter was 0.652 m. The flow was simulated in the range of axial velocity at the inlet from 80 to 200 m/s at a relative rotor speed of 0.65, 0.85, and 0.9. For the investigated tandem fan impeller, the chord of the first row was 60% of the total chord of the profile, the length of the slotted channel was 10% of the total chord. The flow was simulated using a numerical experiment. When closing the system of Navier-Stokes equations, Menter's SST turbulence model was used. The computational grid is unstructured, with an adaptation of the boundary layer. The work shows that the use of a tandem impeller will improve the aerodynamic characteristics of the fan. As a result of the study, it was found that the pressure ratio in a fan with tandem impeller increases from 0.32 to 20% for an operating mode at a relative rotor speed of n=0.65, n=0.85, and n=0.9 in the range of values of the gas-dynamic flow rate function q (λ)=0.4...1. The greatest growth is observed on the left branches of the pressure lines. The obtained data on the efficiency of a fan with a tandem impeller showed that in the range of values of the gas-dynamic flow rate function q(λ)=0.4...0.6 and q(λ)=0.76...0.98 a tandem impeller is higher than the efficiency of a fan with a single-row impeller, for values of the gas-dynamic flow function q(λ)=0.64...0.76 - the efficiency of a fan with a tandem impeller is 4% less than the efficiency of a fan with a single-row impeller.

scholarly journals ВИБІР І ОБҐРУНТУВАННЯ МЕТОДУ ГЕНЕРАЦІЇ СІТКИ ДЛЯ МОДЕЛЮВАННЯ ТЕЧІЇ У ВЕНТИЛЯТОРІ ГАЗОТУРБІННОГО ДВИГУНА

2020 ◽  
pp. 34-40
Author(s):  
Михаил Владимирович Хижняк ◽  
Екатерина Викторовна Дорошенко ◽  
Вячеслав Юрьевич Усенко
Keyword(s):  
Finite Element ◽  
Literature Review ◽  
Numerical Experiment ◽  
Flow Function ◽  
Dynamic Flow ◽  
Axial Fan ◽  
Hybrid Mesh ◽  
Gas Dynamic ◽  
Structured Mesh ◽  
Bypass Ratio

The study of flow in aircraft gas turbine engines is one of the main components for the creation of new compressors and fans with improved aerodynamic, acoustic, strength, overall weight, and other characteristics. In modern scientific research, the methods of the physical experiment are used at the final stages of flow studies in blade machines. a numerical experiment is used in the early stages. An obvious advantage of the numerical experiment is the ability to study many variants of constructions under different input and boundary conditions in a short period. However, a numerical experiment requires a preliminary selection and justification of its parameters and components. One such important component is the type of calculation mesh. The literature review shows that it is impossible to make an unambiguous conclusion about the choice of the type of method for generating the finite element mesh and the turbulence model. This work aims to compare a hybrid and structured mesh for flow modeling in an axial fan of a bypass engine with a high bypass ratio. Two impellers of a bypass engine with a high bypass ratio are selected as the object of study. Flow simulation in fans was studied at a rotor speed of 2202 rpm in the range of values of the gas-dynamic flow function at the inlet q (λ) = 0.4 ... 0.65. Based on the literature review, the system of Navier-Stokes equations was closed by the SST turbulent model. To select and substantiate the method of finite-element grid generation, a structured and hybrid mesh for two fan variants were constructed. According to the results of the calculations, the dependence of the pressure ratio of fan π on the gas-dynamic flow function at the inlet q (λ) was constructed. According to the results of the study, it can be stated that the discrepancy of the calculations for the impellers in the axial fan of a bypass engine with a high bypass ratio with structured and hybrid meshes will be up to 2 %. When choosing the method of mesh generation, the time of calculation is also an important factor. Studies have shown that the calculation with a structured mesh took place in less time by 50 ... 70% than when using a hybrid mesh for one variant of the geometry.

INFLUENCE OF HIGH-BYPASS-RATIO TURBOFAN JETS ON AERODYNAMIC CHARACTERISTICS OF HIGH-LIFT WING

2015 ◽  
Vol 46 (7) ◽  
pp. 619-629
Author(s):  
Albert Vasilievich Petrov ◽  
Vladimir Fedorovich Tretyakov
Keyword(s):  
Aerodynamic Characteristics ◽  
High Lift ◽  
Bypass Ratio

Effect of electric-discharge plasma on gas-dynamic flow modes of a supersonic jet impinging on a barrier

2015 ◽  
Vol 60 (4) ◽  
pp. 160-163
Author(s):  
V. M. Fomin ◽  
K. A. Lomanovich ◽  
B. V. Postnikov
Keyword(s):  
Electric Discharge ◽  
Discharge Plasma ◽  
Supersonic Jet ◽  
Dynamic Flow ◽  
Gas Dynamic

A Simple and Robust Subsonic Boundary Layer Method to Be Used with the Panel Method for Wing Calculations Using a Wing Strip Approach

2015 ◽  
Vol 798 ◽  
pp. 596-601
Author(s):  
R.F. Francisco Reis ◽  
Guilherme A. Santana ◽  
Paulo Iscold ◽  
Carlos A. Cimini
Keyword(s):  
Boundary Layer ◽  
Lift Coefficient ◽  
Aircraft Design ◽  
Aerodynamic Characteristics ◽  
Viscous Drag ◽  
Layer Method ◽  
Boundary Layer Method ◽  
Dimensional Boundary ◽  
Classical Integral ◽  
Empirical Corrections

This paper will present the development of a simple subsonic boundary layer method suitable to be used coupled with panel methods in order to estimate the aerodynamic characteristics, including viscous drag and maximum lift coefficient, of 3D wings. The proposed method does not require viscous-inviscid iterations and is based on classical integral bi-dimensional boundary layer theory using Thwaites and Head ́s models with bi-dimensional empirical corrections applied to each wing strip being therefor robust and efficient to be used in the early conceptual stage of aircraft design. Presented results are compared to the Modified CS Method in an IBL scheme and experimental data and are shown to provide good results.

Future Trends in Aircraft Engine Noise Research

1970 ◽  
Author(s):  
Jervis D. Kester
Keyword(s):  
Power Plant ◽  
Aircraft Engine ◽  
Low Noise ◽  
Future Research ◽  
Noise Generation ◽  
Future Trends ◽  
Noise Abatement ◽  
Engine Component ◽  
Bypass Ratio ◽  
Selection Of

The high bypass ratio engines being introduced into service have generally been acknowledged to provide significant improvement in noise abatement. Substanital improvements in future designs will require research into several areas of engine-component noise generation. Low-noise standards also will be influenced by the aircraft mission requirements that affect selection of the power-plant cycle. Each mission requirement presents special noise problems, which must be solved. This paper explores the relationships among aircraft mission requirements, noise research in process at Pratt & Whitney Aircraft, and trends predicted for future research.

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