6.1. KiteFAST Example Cases

Various test cases were created throughout the development process with a varying degree of complexity. All test cases are located at sandbox/glue-codes/kitefast/test_cases.

Unless otherwise noted, all cases share common input files which are located at

test_cases
├── hydrodyn
├── kiteaerodyn
├── kiteinflow
└── kitemooring

The included tests cases are listed below starting with the simplex and ending with the most complex. A short description of each follows.

test_cases
├── two_element_beam
├── makani_floater
├── m600_prescribed_circle
├── m600_prescribed_circle_STIFF
├── m600_salf
├── m600_eigenanalysis
├── m600
└── m600_platform

6.1.1. two_element_beam

This is a test case for the KiteMBDyn Preprocesser only. It consists of a few simple “components” made of two or three beam-elements. This has primarily been used to understand the manner in which the mass and inertias are distributed and how MBDyn reacts.

This is a good case to understand the mechanics of the preprocessor and the structure of the MBDyn input files, in general. It has elements and nomenclature in common with a kite model, but it is a more generalized case. While it does not run the KiteFASTMBD interface, it does generate files which can be run with MBDyn alone.

6.1.2. makani_floater

This case models only the buoy system for an offshore simulation. This is a single body floating in water with waves and moored.

The KiteMBDyn Preprocessor input file is included and should be used to generate the MBDyn case files.

6.1.3. m600_prescribed_circle

This test case contains the geometry of a simplified m600 kite. By default, KiteAeroDyn, InflowWind, and MoorDyn are enabled, but the controller is disabled. The initial conditions are such that simulation begins with the kite already in its crosswind loop.

This case specifies the position of the kite as a function of time. As such, it is NOT free flying. This case is a good test for any modifications of a component of the system as the aeroelastics are actually calculated but the result is not fully coupled in the response.

The MBDyn input files are included directly in the repository and no preprocessor input files is included. This case was created manually so that the position could be prescribed to MBDyn. To modify this case, start with KiteMain.mbd. The position as a function of time is described in position.csv.

6.1.4. m600_prescribed_circle_STIFF

This test case is the same as m600_prescribed_circle with the addition of joints from the end of each component that rigidly connect it to the closest wing root node.

6.1.5. m600_salf

This test case contains the geometry of a simplified m600 kite. By default, KiteAeroDyn, InflowWind, and the controller are enabled, but MoorDyn is disabled (meaning there is no tether). The initial conditions are such that the kite begins its flight in a straight and level orientation (SALF = straight and level flight).

The preprocessor input file is included and should be used to generate the mbdyn case files.

6.1.6. m600_eigenanalysis

This test case contains the geometry of a simplified m600 kite. Rather than simulating a time marching flight, this case performs an Eigenanalysis of the structure in the absence of aerodynamics, the tether, and control actions (all modules are disabled).

NOTE: Configuring MBDyn with –enable-netcdf –with-lapack –enable-eig is required to use the eigen analysis features of this case.

The preprocessor input file is included with this case. This includes the directive to setup the eigen analysis. To create the case, run the preprocessor as per usual to create the MBDyn input file set. When the eigen analysis is performed, the begining of the KiteMain.out file will contain the results of the eigen analysis with the real, imaginary, damping, and frequency results for each of the modes. This may include several hundred modes. Visualization of the modes can be done with BlenDyn in Blender.

NOTE: dummy nodes cannot be included in the KiteMain.mbd. These will cause parsing issues when BlenDyn is used to visualize modes with Blender.

6.1.7. m600

This is the main demonstrator for the onshore simulation.

This test case contains the geometry of a simplified m600 kite. By default, all physics modules are enabled. The initial conditions are such that simulation begins with the kite already in its crosswind loop.

The KiteMBDyn Preprocessor input file is included and should be used to generate the MBDyn case files.

6.1.8. m600_platform

This is the main demonstrator for the offshore simulation.

This test case contains the geometry of a simplified m600 kite tethered to a buoy which is moored to the ocean floor. By default, all physics modules are enabled. The initial conditions are such that simulation begins with the kite already in its crosswind loop.

The KiteMBDyn Preprocessor input file is included and should be used to generate the MBDyn case files.