propulsion Class Reference

Models a pulsewidth modulated suite of thrusters with a single blowdown tank. More...

#include <propulsion.h>

Inherits dsim_model.

Public Member Functions
	propulsion (dsim_model_setup *setup)
	Constructor.
	~propulsion ()
	Destructor.
void *	describe_setup (void *ds)
	Describe the setup variables.
bool	parse_setup (const char *command, const char *data)
	Parse the setup file for variables. More...
void	initialize_data ()
	Initialize outlets and output variables.
void	initialization_complete ()
	Finish initialization.
void	initialize_timestep ()
	Computation done prior to numerical integration. More...
void	rhs (double t, double jd)
	Right-hand-side. More...
void	complete_timestep ()
	Computation done after numerical integration.

Detailed Description

Models a pulsewidth modulated suite of thrusters with a single blowdown tank.

A pulsewidth command is sent to the thrusters. The thrusters then fire until the pulsewidth is complete.

A blowdown system is assumed using Helium as the pressurant. The pressure is modeled assuming a single tank. The fuel mass is an integrated state so that fuel consumption is tracked.

Each thruster can have a catalyst bed. The length of the catalyst bed must be the same as the length of the thrusters.

Thrusters are added using a AddThruster setup directive. The thrust model is

Thrust = T*P

where T is the thrust coefficient and P is the current tank pressure.

Member Function Documentation

parse_setup()

bool propulsion::parse_setup	(	const char *	command,
		const char *	data
	)

Parse the setup file for variables.

Processes AddThruster commands.

The data is a matrix of 11 parameters, including in order:

• position (vector to thruster CM), 3 elements
• thrust unit vector, 3 elements
• thrust coefficient (N/bar)
• exhaust velocity of the thruster (m/s)
• minimum impulse bit (sec)
• thruster nozzle base width (m)
• thruster fuel type (0 = fossil fuel, 1 = hydrogen)

initialize_timestep()

void propulsion::initialize_timestep

(

)

Computation done prior to numerical integration.

See also

BloDown()

rhs()

void propulsion::rhs	(	double	t,
		double	jd
	)

Right-hand-side.

The right hand side applies the force and torque to the parent object and computes the fuel mass derivative using the mass flow.

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The documentation for this class was generated from the following files:

• propulsion.h
• propulsion.cc