sc_propulsion.h File Reference

Propulsion modeling functions. More...

Go to the source code of this file.

Classes
struct	aero_info
	Aerodynamic information. More...

Functions
double	thruster_power (double thrust, double u_e, double eff)
	General power required by a thruster. More...
double	boron_proton_thruster_exhaust_velocity (double n_protons)
	Boron-proton exhaust velocity. More...
double	BloDown (double mPress, double rhoFuel, double vTank, double rPress, double T, double mFuel)
	Blow down pressurized fuel system model. More...
ml_matrix	EngineDataFromTable (ml_matrix thrustTable, ml_matrix sFC_Table, ml_matrix mach_no, ml_matrix altitude, double m, double h)
	Extracts engine data from a table. Outputs thrust and specific fuel consumption. More...
double	area_ratio_from_mach (double M, double gamma)
	Computes area ratio to mach number. More...
double	isentropic_expansion (double M, double gamma)
	Computes the isentropic expansion of a gas. More...
double	ue_qr (double qR, double gamma, double p0, double pE)
	Exhaust velocity from heating value. More...
double	qr_hydrogen (void)
	Heating value of hydrogen. More...
double	mach_from_area_ratio (double aR, double gamma)
	Mach number from area ratio. More...
ml_matrix	RocketH2 (double p0, double pA, double aStar, double aE, double f)
	Thrust and exhaust velocity of an H2/O2 rocket. More...
double	rhs_mach_from_area_ratio (double M, void *context)
	Right hand side of the minimization algorithm for mach from area ratio. More...
ml_matrix	solid_rocket_inertia (double mDot, double a, double b, double rho, double h)
	Solid rocket model. More...
double	FindH (double r, double d, double tol, int nMax)
	Bisection routine to find the height of a fluid in a sphere. More...
double	TankHeight (double r, double vF)
	Find the height of a fluid in a sphere. More...

Detailed Description

Propulsion modeling functions.

Function Documentation

thruster_power()

double thruster_power	(	double	thrust,
		double	u_e,
		double	eff
	)

General power required by a thruster.

General power required by a thruster.

Parameters

thrust	Thrust (N)
u_e	Exhaust velocity (m/s)
eff	Thruster efficiency

Returns

power Power (W)

boron_proton_thruster_exhaust_velocity()

double boron_proton_thruster_exhaust_velocity

(

double

n_protons

)

Boron-proton exhaust velocity.

Boron-proton exhaust velocity.

Parameters

n_protons

Number of protons

Returns

Exhaust velocity (m/s)

BloDown()

double BloDown	(	double	mPress,
		double	rhoFuel,
		double	vTank,
		double	rPress,
		double	T,
		double	mFuel
	)

Blow down pressurized fuel system model.

Blow down pressurized fuel system model.

Parameters

mPress	Mass of pressurization gas
rhoFuel	Fuel density
vTank	Tank volume
rPress	Gas constant of pressurant
T	Temperature
mFuel	Mass of fueld

Returns

Pressure

EngineDataFromTable()

ml_matrix EngineDataFromTable	(	ml_matrix	thrust_Table,
		ml_matrix	sFC_Table,
		ml_matrix	mach_no,
		ml_matrix	altitude,
		double	m,
		double	h
	)

Extracts engine data from a table. Outputs thrust and specific fuel consumption.

Compute the difference between successive elements of a 1-dimensional matrix
\param  thrust_Table    2-dimensional matrix, size n, m
\param  sFC_Table       2-dimensional matrix, size n, m
\param  mach_no         1-dimensional matrix, size 1, m
\param  altitude        2-dimensional matrix, size 1,n

Parameters

m	Mach number to compute
h	Altitude

Returns

b 1-dimensional matrix, [thrust;sFC]

References interp_2d().

area_ratio_from_mach()

double area_ratio_from_mach	(	double	M,
		double	gamma
	)

Computes area ratio to mach number.

Computes area ratio to mach number.

Parameters

M	Mach number.
gamma	Ratio of specific heats.

Returns

Area ratio.

Referenced by rhs_mach_from_area_ratio().

isentropic_expansion()

double isentropic_expansion	(	double	M,
		double	gamma
	)

Computes the isentropic expansion of a gas.

Computes the isentropic expansion of a gas.

Parameters

M	Mach number.
gamma	Ratio of specific heats.

Returns

Expansion ratio.

Referenced by RocketH2().

ue_qr()

double ue_qr	(	double	qR,
		double	gamma,
		double	p0,
		double	pE
	)

Exhaust velocity from heating value.

Exhaust velocity from heating value.

Parameters

qR	Heating value (J/kg)
gamma	Ratio of specific heats.
p0	Combustion chamber pressure (N/m^2).
pE	Exhaust pressure (N/m^2).

Returns

exhaust velocity.

Referenced by RocketH2().

qr_hydrogen()

double qr_hydrogen

(

void

)

Heating value of hydrogen.

Returns

heating value (J/kg).

Referenced by RocketH2().

mach_from_area_ratio()

double mach_from_area_ratio	(	double	aR,
		double	gamma
	)

Mach number from area ratio.

Mach number from area ratio.

Parameters

aR	Area ratio.
gamma	Ratio of specific heats.

Returns

Mach number.

References aero_info::aR, aero_info::gamma, rhs_mach_from_area_ratio(), and secant().

Referenced by RocketH2().

RocketH2()

ml_matrix RocketH2	(	double	p0,
		double	pA,
		double	aStar,
		double	aE,
		double	f
	)

Thrust and exhaust velocity of an H2/O2 rocket.

Thrust and exhaust velocity of an H2/O2 rocket.

Parameters

p0	Combustion pressure (N/m^2).
pA	Ambient pressure (N/m^2).
aStar	Throat area (m^2).
aE	Exit area (m^2).
f	Mixture ratio H2/O2.

Returns

[thrust (N);exhaust velocity (m/s)].

References isentropic_expansion(), mach_from_area_ratio(), qr_hydrogen(), and ue_qr().

rhs_mach_from_area_ratio()

double rhs_mach_from_area_ratio	(	double	M,
		void *	context
	)

Right hand side of the minimization algorithm for mach from area ratio.

Right hand side of the minimization algorithm for mach from area ratio.

Parameters

M	Mach number.
*context	Pointer to data structure. Needs to contain the ratio of specific heats

Returns

error.

References aero_info::aR, area_ratio_from_mach(), and aero_info::gamma.

Referenced by mach_from_area_ratio().

solid_rocket_inertia()

ml_matrix solid_rocket_inertia	(	double	mDot,
		double	a,
		double	b,
		double	rho,
		double	h
	)

Solid rocket model.

Solid rocket model.

Assumes a cylindrical solid rocket with a cylindrical burn surface.

Parameters

mDot	Mass flow (kg/s).
a	Outside radius (m).
b	Inside radius (m).
rho	Fuel density (kg/m^3).
h	Fuel height (m).

Returns

[Ixx IDotxx; Iyy IDotyy; Izz IDotzz].

References PI.

FindH()

double FindH	(	double	r,
		double	d,
		double	tol,
		int	nMax
	)

Bisection routine to find the height of a fluid in a sphere.

Bisection routine to find the height of a fluid in a sphere.

Parameters

r	Sphere radius
d	3*volume fuel/pi
tol	Solution tolerance
nMax	Maximum number of iterations

Returns

h Fuel height

Referenced by TankHeight().

TankHeight()

double TankHeight	(	double	r,
		double	vF
	)

Find the height of a fluid in a sphere.

Find the height of a fluid in a sphere.

Parameters

r	Sphere radius
vF	Volume of fuel

Returns

h Fuel height

References FindH(), and PI.