payload Directory Reference

Directory dependency graph for payload:

Files
	__init__.py
	cold_gas_thruster.py
	optimize_cgt.py
	test_controller_l2_integration.py

Detailed Description

Payload Analysis Module

This directory contains tools for analysing cold gas thruster (CGT) performance and their effects on rocket dynamics.

Cold Gas Thruster Analysis (cold_gas_thruster.py)

This module provides a comprehensive physics-based simulation of CO₂ cold-gas thrusters. It handles everything from internal nozzle flow to the resulting angular acceleration of the vehicle.

Key Features

• Isentropic Flow Solver: Uses a robust area-Mach solver to compute nozzle exit conditions (Mach number, velocity, temperature, and pressure).
• Performance Metrics: Calculates thrust (momentum + pressure components), mass flow rate, and specific impulse (Isp).
• Dynamic Analysis: Estimates the torque and angular acceleration ($\alpha$) applied to the rocket, accounting for the thruster's location and the rocket's moment of inertia.
• Nozzle Design: Includes logic to generate Rao bell nozzle contours and automated plotting.

Physics & Assumptions

• Gas: Defaults to CO₂ ($\gamma = 1.289$, $M = 44.01 \text{ g/mol}$).
• Flow Model: 1D isentropic flow through a converging-diverging (CD) nozzle.
• Choking: Automatically checks the stagnation-to-ambient pressure ratio to determine if the throat is choked ($M=1$).
• Efficiency: Applies a nozzle efficiency factor (default 0.95) to the ideal exit velocity.

Usage

You can run a demo analysis by executing the module directly from the repository root:

python3 -m payload.cold_gas_thruster

To integrate it into your own scripts:

from payload.cold_gas_thruster import ColdGasThruster, ColdGasThrusterConfig
 
# 1. Define configuration
cfg = ColdGasThrusterConfig(
    throat_diameter=0.005,    # 5 mm
    exit_diameter=0.015,      # 15 mm
    inlet_pressure=800_000,   # 800 kPa
)
 
# 2. Run analysis
cgt = ColdGasThruster(cfg)
result = cgt.compute()
 
# 3. View results
print(result.summary())
 
# 4. (Optional) Generate nozzle contour plot
cgt.generate_nozzle_contour(do_plot=True)

Outputs

• Console Summary: A detailed breakdown of areas, exit conditions, and performance totals.
• cgt_nozzle.png: A visualization of the generated nozzle contour (saved when do_plot=True in generate_nozzle_contour).