Numerical method for simulating helicopter rotor wakes

A helicopter rotor, numerical method technology, applied in the numerical field, can solve problems such as the inability to further improve, the uncertainty of the stability effect of convergence, etc.

Inactive Publication Date: 2013-04-24
TIANJIN AEROCODE ENG APPL SOFTWAREDEV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] 2. The spatial discrete precision of the added vorticity is limited and cannot be further improved;
[0010] 3. The stability effect of the source term on the convergence of the numerical solution of the momentum equation is uncertain

Method used

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  • Numerical method for simulating helicopter rotor wakes
  • Numerical method for simulating helicopter rotor wakes
  • Numerical method for simulating helicopter rotor wakes

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Embodiment Construction

[0070] Further illustrate what the present invention proposes with a specific embodiment below, this numerical simulation technology can realize with Fortran90 computer high-level programming language, and simulate the wake of the three-dimensional rotor of NACA0012 shape cross section under the high angle of attack flight state by computer operation Flow field.

[0071] In a specific embodiment, the helicopter employs four rotating wings with a rotor-to-wing ratio of seven. Such as image 3As shown, the section is the 3D airfoil and computational domain of NACA0012. The computational domain takes a quarter-quadrant, which contains a wing, and the Z-axis is the axis of rotation. The calculation grid adopts multi-block structured hexahedral grid. According to the characteristics of the helicopter rotor flow field, the calculation domain is divided into five blocks: far field (1), wake (2), and near field (3). O-shaped grids are used around the wing, with 192 grids around th...

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Abstract

The invention provides a numerical method for simulating helicopter rotor wakes. According to characteristics of incompressible flows, two forms of force are added in a momentum equation to improve numerical simulation accuracy of the vortical-motion-oriented flow field. The two forms of force are respectively vortical force and viscous dissipation force of a vorticity in the changing gradient direction. The numerical method enables integral calculation of the vortical force of the vorticity in a computational grid in the changing gradient direction to be converted into flux calculation of force on a boundary of the computational grid and can enable spatial dispersion to have a high-order accuracy form. In addition, the viscous dissipation force of the vorticity in the changing gradient direction is retained by a source item of the momentum equation so as to improve convergence and stability of a numerical solution. The two forms of force adopt different amplification coefficients, the accuracy of the vorticity can be further kept, and vortical motion of the helicopter rotor wakes can be accurately simulated.

Description

technical field [0001] The invention relates to a numerical method in the application field of computational fluid dynamics (CFD: Computational Fluid Dynamics), in particular to a numerical method for simulating the wake of a helicopter rotor. Background technique [0002] With its good maneuverability and flexibility, helicopters are widely used in military, civil and other fields. The main rotor of a helicopter is multipurpose, and it simultaneously plays the role of wing, elevator, rudder and propulsion device structurally. The movement of the flow field around the rotor is more complex than that of a fixed wing. Such as figure 1 As shown, the wake flow field of the helicopter rotor includes two types of vortex-dominated flows. One is the tip vortex generated at the tip of the rotor in the span direction, that is, the tip of the wing; the other is the shedding vortex generated on the surface of the rotor. The formation of wingtip vortex is due to the difference in pre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F19/00
Inventor 路明
Owner TIANJIN AEROCODE ENG APPL SOFTWAREDEV
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