This is a 6 degree of freedom model developed by a group of enthusiastic engineers who were part of thrustMIT (MIT Manipal's Rocketry team). This model was inspired by the absence of physical testing of sounding rockets in India leading to the formation of this high-precision model. This model provides you with multiple features
A 6 degree-of-freedom rocket model is a simulation that accurately models the motion of a rocket in flight, taking into account atmospheric conditions, turbulence, and aerodynamic parameters. It calculates the trajectory, apogee, and other parameters of the rocket at every time interval using detailed information about the motor, rocket, and aerodynamics. This type of model is essential for predicting the behavior of rockets during flight and optimizing their performance. The model takes into account factors such as air density, wind speed, and turbulence to simulate the rocket's trajectory accurately. It also considers the rocket's weight, shape, and aerodynamic properties to predict its behavior as it flies through the air. In the case of the validated rocket launch at Spaceport America in New Mexico, the model accurately predicted the rocket's apogee to within 34 feet of the actual altitude reached. This level of accuracy demonstrates the effectiveness of the model and its ability to provide valuable insights into rocket performance.
There are specific inputs required for the model to run which includes:
- Aerodynamic Coefficients Data
- Motor thrust vs time data
- Initial Yaw angle
- Initial Pitch angle
- Wind velocity in north direction
- Wind velocity in east direction
- Turbulance Intensity
- Launch Rail height
- Aibrakes (Y/N)
- Desired Apogee
- Parachute diameter
- Reefed parachute diameter
- Reefing Height
- Rocket mass
- Rocket CG
- Rocket's axial moment of inertia
- Rocket's transverse moment of inertia
- Rocket's Radius
- Rocket's diameter
- Fin root chord
- Fin tip chord
- Fin Height
- Fin sweep length
- Fin's Distance from nosetip
- Motor Length
- Motor diameter
- Motor wet Mass
- Motor dry mass
- Nozzle mass
- Nozzle Length
- Simulation Time step
Use the following to download the package from the PyPi Repository:
pip install helios-sim
Once the package has been installed on the machine and the requirements are satisfied use the following command to run the Helios Simulator:
helios -[options] [values]
The following is an example for running the code with all parameters passed through CLI:
helios --yaw 2 --pitch 2 --wind-north 2 --wind-east 2 --turb-inten 5 --rail-length 5.18 --air-brakes 'n' --desired 3048 --parachute-dia 3 --reefed-parachute-dia 0.8 --reefed-height 460 --rocket-mass 26.4 --rocket-cg 1.92 --rocket-ami 0.09 --rocket-tmi 17.77 --rocket-dia 0.15 --rocket-rad 0.075 --rocket-length 3.03 --fin-root-chord 0.3 --fin-tip-chord 0.2 --fin-height 0.145 --fin-sweep-length 0.179 --fin-dist-nosetip 2.6 --motor-length 0.702 --motor-odia 0.098 --motor-wetmass 8.108 --motor-drymass 3.656 --noz-mass 0.1891 --noz-length 0.057 --prop-data 'prop_data.xlsx' --aero-data 'aero_data.xlsx' --delaytracker 0 --delay 1 --time-step 0.001 -o 'helios_output.pdf'
The output for the simulations run is stored in a PDF file as follows:
output.pdf
Users can change the input values through 2 methods.
- Opening '.env' file and manually overridding values of necessary parameters.
- Using CLI commands to override values. If you are unsure of what values corresponds to what parameter, simply type "HeliosSim --help" command will help the user obtain the CLI commands required
There are two extra excel data the motor data can be obtained from thrust-time curve or commercial-off-the-shelf Computational fluid dynamics softwares like Ansys. By default there are example excels present within the package and the user can change the files. The model will have variable computational time depending upon the number of iterations considered through user inputs.
Peformance Improvements, bug fixes, better design approaches are welcome. Please Discuss your change by raising an issue, beforehand. Advancements to the model are appreciated.