ZESt Description

ZESt is ZONA’s Euler Steady solver with a boundary layer option for rapid aerodynamic shape design and flight loads analysis. ZESt is a simplified version of ZONA’s Euler Unsteady Solver (ZEUS) specially developed for aerodynamic and flight loads analysis. The majority of the ZESt input cards are very similar to that of ZEUS except all the input cards related to dynamic aeroelastic analysis were removed from ZEUS and a few new bulk data cards that are streamlined for steady aerodynamic analysis are introduced into ZESt. These simplified input cards make the input of ZESt more user-friendly for aerodynamic and loads engineers. In addition, the time-accurate scheme in ZEUS for solving the Euler equation is replaced by a pseudo time scheme in ZESt for a fast steady aerodynamic solution convergence.

• A shape design variable linking scheme has been incorporated into ZESt for rapidly changing aerodynamic geometry.
• Incorporates a robust and fully automated mesh generation scheme identical to ZEUS (i.e., 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.
• Does not require the tedious grid generation effort (i.e., as required by CFD codes) making it an ideal aerodynamic analysis tool for rapid aerodynamic configuration design.
• Ideally suited for the conceptual design stage where a large number of different aerodynamic design concepts must be evaluated in a short period of time.
• Uses a state-of-the-art Euler solver as the underlying aerodynamic force generator (with or without boundary layer coupling).
• Solves the Euler equations with boundary layer coupling with viscous effects included and therefore provides a good balance between complete modeling of the flow physics and computational efficiency.

• 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.
• ZESt can couple with structural finite element modal solutions to perform a trim analysis with flexibility effects and can generate the required flight loads for subsequent stress analysis of the structure.
• Includes the following engineering discipline modules:
  
  • ➤ AEROGEN - to compute the steady aerodynamics
  • ➤ TRIM - to perform a static aeroelastic trim analysis
  
  
  

Completely Automated Mesh Generation Scheme

Similar to ZEUS:

• ZESt solves the Euler’s equation with a small disturbance boundary condition.
• ZESt's 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.
• The majority of the ZESt input 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 ZESt Panel Model Splined to FEM Model