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.
ZONE 1: Left launcher
ZONE 2: Outboard left wing
ZONE 3: Inboard left wing and outboard left horizontal tail
ZONE 4: Outboard left strake and inboard left horizontal tail
ZONE 5: Inboard left strake
ZONE 6: Fuselage
ZONE 7: Inboard right strake
ZONE 8: Outboard right strake and inboard right horizontal tail
ZONE 9: Inboard right wing and outboard right horizontal tail
ZONE 10: Outboard right wing
ZONE 11: Right launcher
Overset Mesh for Complex Configuartions
- Complex configurations can be modeled by multiple blocks of mesh with over-lapping regions; the overset mesh.
- Communication of flow solutions among blocks is through the interpolation of solutions in the overlapping regions.
- Solution convergence is acheived by sub-iterations.
3D Spline Module
The 3D Spline module establishes the displacement/force transferal between the structural Finite Element Method (FEM) module and the ZESt surface panel model.
It consists of four spline methods that jointly assemble a spline matrix. These four spline methods include:
- Thin Plate Spline
- Infinite Plate Spline
- Beam Spline
- Rigid Body Attachment methods
The spline matrix provides the x, y and z displacements and slopes in three dimensions at all aerodynamic grids.
Displacement of ZESt Panel Model Splined to FEM Model
ZESt Licensing Information
ZESt is available for annual licensing (1 token = 1 license).
Features included with the ZESt License:
- A CFD code whose program architecture is specially designed for aeroelasticians.
- Euler solver with boundary layer option to provide an appropriate balance between the complete modeling of flow physics and computational efficency.
- Automated mesh generation requiring only the surface panel model as input.
- Overset mesh scheme for modeling of complex configurations such as whole aircraft with external stores.
- Includes ZAERO 3D spline module and FEM modal solution importer.
- Supports parallel computation using OpenMP.
- Generates steady aerodynamics and static/trim aeroelastic analysis results.
- ZONA will assist the new user by telephone/fax/email consultation to successfully run test cases in the documentation (i.e., turn-key operation) at no cost to the user.
- Customer service is included in the annual license fee (up to 20 hours per year by telephone, fax, email, etc.) Additional support will be charged at ZONA’s T&M rate.
- Includes software upgrades as they become available.
System Requirements and Platform
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