ZEUS' Description

ZEUS is ZONA’s Euler Unsteady Aerodynamic Solver that integrates the essential disciplines required for aeroelastic design/analysis. It uses an Euler equation solver as the underlying aerodynamic force generator coupled with structural finite element modal solution to solve various aeroelastic problems such as flutter, maneuver loads, gust loads, and static aeroelastic/trim analysis. Structural nonlinearities can also be included to perform a nonlinear aeroelastic analysis.

The Euler equation solver solves the Euler equations on a Cartesian grid system using a cell-centered finite volume method with dual-time stepping algorithm for unsteady solutions. The viscous effects are included by coupling the Euler solution with a steady boundary-layer equation. For turbulence closure, the Green’s lag entrainment is employed. Because ZEUS solves the Euler equations with boundary layer coupling, the requirement of large computing resources by a Navier-Stokes code can be avoided. Therefore, ZEUS provides a good balance between the complete modeling of the flow physics and the computational efficiency.

• Incorporates a robust and fully automated mesh generation scheme making the input setup to ZEUS as simple as that of ZAERO. No more manual mesh set ups!
• Includes an overset mesh generation option so that different aircraft components (e.g., stores) can be set up within their own automated mesh.
• Uses a state-of-the-art Euler solver as the underlying aerodynamic force generator (with or without boundary layer coupling).
• Supports the following unsteady aerodynamic computations:
  
  • ➤ Time-Domain
  • ➤ Frequency-Domain
  • ➤ Pseudo time-domain
  • ➤ Steady aerodynamics for rigid aircraft
  • ➤ Discrete Gust
• Incorporates a High Fidelity Geometry Module (same as ZAERO's).
• Incorporates a robust 3D spline module (same as ZAERO's).
• Utilizies ZONA's Dynamic Database and Memory Managements System.
• Includes the following engineering modules:
  
  • ➤ Flutter
  • ➤ Maneuver Loads
  • ➤ Gust Loads
  • ➤ Nonlinear Flutter
  • ➤ Trim
  • ➤ Frequency-domain Generalized Aerodynamic Force Generator

Completely Automated Mesh Generation Scheme

• Because ZEUS solves the Euler’s equation with a small disturbance boundary condition, all required geometric information existing in ZAERO is sufficient for ZEUS input.
• ZEUS mesh is generated by an automated mesh generation scheme.
• Fuselage, wing, horizontal tail, vertical tail, launcher and pylons can be fitted into a single block of mesh.
• Tip missile with fins and under wing stores can be fitted into other blocks of mesh, respectively.
• Communication between blocks of mesh is accomplished through the overset grid scheme.
• Each block of mesh is automatically generated by a Y-Zone technique.
• 95% of the input for ZEUS is identical to that of ZAERO.

Y-Zone Technique For Automated Mesh Generation

All components within each block are projected on an X-Y plane. On this X-Y plane, all components are divided into several spanwise zones, called the Y-Zones. The Y-Zone technique can automatically generate the mesh by a line-tracing method that spans across all Y-Zones. An example of division of an aircraft model into spanwise zones is shown at right with descriptions of each zone listed below.

Overset Mesh for Complex Configuartions

3D Spline Module

Displacement of ZEUS Panel Model Splined to FEM Model

Click here to view Validation Test Cases.