solve_states

solve_states uses numerical integration to solve for the dynamic response of the balloon.

class solve_states.SolveStates[source]
__init__()[source]

Initializes all of the solar balloon paramaters from the configuration file

get_acceleration(v, el, T_s, T_i)[source]

Solves for the acceleration of the solar balloon after one timestep (dt).

\[\frac{d^2z}{dt^2} = \frac{dU}{dt} = \frac{F_b-F_g-F_d}{m_{virtual}}\]

The Buyoancy Force, F_{b}:

\[F_b = (\rho_{atm}-\rho_{int}) \cdot V_{bal} \cdot g\]

The drag force, F_{d}:

\[F_d = \frac{1}{2} \cdot C_d \cdot rho_{atm} \cdot U^2 \cdot A_{proj} \cdot \beta\]

and where the virtual mass is the total mass of the balloon system:

\[m_{virt} = m_{payload}+m_{envelope}+C_{virt} \cdot \rho_{atm} \cdot V_{bal}\]
Parameters:
  • T_s (float) – Surface Temperature (K)

  • T_i (float) – Internal Temperature (K)

  • el (float) – Elevation (m)

  • v (float) – Velocity (m)

Returns:

acceleration of balloon (m/s^2)

Return type:

float

get_convection_vent(T_i, el)[source]

Calculates the heat lost to the atmosphere due to venting

\[Q_{vent} = \dot{m} \cdot c_v \cdot (T_i-T_{atm})\]
Parameters:
  • T_i (float) – Internal Temperature (K)

  • el (float) – Elevation (m)

Returns:

Convection due to Venting (unit?)

Return type:

float

solveVerticalTrajectory(t, T_s, T_i, el, v, coord, alt_sp, v_sp)[source]

This function numerically integrates and solves for the change in Surface Temperature, Internal Temperature, and accelleration after a timestep, dt.

\[\frac{dT_s}{dt} = \frac{\dot{Q}_{rad}+\dot{Q}_{conv,ext}-\dot{Q}_{conv,int}}{c_{v,env} \cdot m_{envelope}}\]
\[\frac{dT_i}{dt} = \frac{\dot{Q}_{conv,int}-\dot{Q}_{vent}}{c_{v,CO_2} \cdot m_{CO_2}}\]
Parameters:
  • t (datetime) – Datetime

  • T_s (float) – Surface Temperature (K)

  • T_i (float) – Internal Temperature (K)

  • el (float) – Elevation (m)

  • v (float) – Velocity (m)

  • alt_sp (float) – Altitude Setpoint (m)

  • v_sp (float) – Velocity Setpoint (m/s)

Returns:

Updated parameters after dt (seconds)

Return type:

float [T_s,T_i,el,v]