Hybrid Rocket Project

21
THIS IS ROCKET SCIENCE: DEVELOPMENT AND TESTING OF A HYBRID ROCKET MOTOR IN A ROCKET PROPULSION COURSE Mechanical Engineering Rowan University 201 Mullica Hill Rd. Glassboro, NJ 08028 http://users.rowan.edu/~marchese 36 th Annual Frontiers in Education Conference San Diego, CA, Oct. 28-31, 2006 Anthony J. Marchese

Transcript of Hybrid Rocket Project

THIS IS ROCKET SCIENCE: DEVELOPMENT AND TESTING OF A HYBRID ROCKET MOTOR IN A ROCKET PROPULSION COURSE

Mechanical EngineeringRowan University

201 Mullica Hill Rd.Glassboro, NJ 08028

http://users.rowan.edu/~marchese

36th Annual Frontiers in Education ConferenceSan Diego, CA, Oct. 28-31, 2006

Anthony J. Marchese

Motivation for a project based learning experience in rocket propulsion

Context: Description of the rocket propulsion course

Description of the project: objectives, requirements and constraints

Development of the analytical model

Design and fabrication of the hardware

Development of the hybrid rocket motor test stand

The Engineering Clinic

Test results

On going tests

This is Rocket Science: The Hybrid Rocket Motor Project

Overview

Rocket propulsion draws upon the fundamental concepts of thermodynamics, chemistry, fluid mechanics and heat transfer to design propulsion systems. At the conclusion of the course, each student will be able to: Analyze the performance of an ideal rocket engine.

Select propellants and choose a rocket propulsion system based on mission requirements.

Perform thermochemical calculations to determine the rocket chamber temperature and chemical composition for any propellant combination.

Design a liquid propellant rocket engine by considering the propellant combination, combustion chamber, injector, igniter, nozzle, heat transfer and cooling characteristics.

Design a solid propellant rocket motor based on the propellant combination, burning rate laws and grain design.

Design a hybrid rocket motor based on the propellant combination, burning rate laws and grain design.

Build and test a 10 lbf thrust hybrid rocket motor.   Measure specific impulse, characteristic exhaust velocity, thrust coefficient and compare to theoretical calculations.

Introduction to Rocket Propulsion (ME 412)

Course Objectives

On October 4, 2004, SpaceShipOne became the first private manned spacecraft to exceed an altitude of 328,000 feet twice within a 2 week period, thereby claiming the $10 million Ansari X-Prize.

SpaceShipOne was powered by a hybrid rocket motor (liquid N2O, solid polymer fuel)

N2O

solid fuel

Private Sector Opportunities in Space Exploration

Motivation for the Hybrid Rocket Motor Project

Objectives, Design Parameters and Constraints

The Hybrid Rocket Motor Design Project

Objectives of the semester design project: Design, build and test a hybrid rocket motor.

Develop a theoretical model that predicts the performance of the hybrid rocket motor as a function of time.

Compare measured performance with theoretical model.

Constraints: Oxidizer must be gaseous oxygen (GOX)

Maximum Chamber Pressure: 115 psia, Ambient Pressure: 14.7 psia

Maximum GOX flow rate: 500 SLPM

Minimum initial thrust: 5 lbf

Fuel grain outer diameter = 1.175 in

Maximum Fuel Grain Length = 12 in

Fuel: HTPB, HTPB/AL, PMMA, PE, UHMW or paraffin

GOX

HTPB/Al graphitealuminum

Theoretical Model: This is Rocket Science

Hybrid Rocket Motor Design Project

n

p

of tA

matr

)()(

n

p

obff tA

matAtm

)()()(

n

p

obfo

tc tA

matAm

A

CtP

)()(

*)(

Ab

solid fuelAp

Liquid oxidizer omfr

fm

AtAe

Pc

m

Tc, Xi,

t

e

cc

eF A

A

P

P

P

PC

1

c

e1)-2(

1

P

P-1

1-

2

1

2

FCCmF *

o

F

o

SP g

CC

dtmg

FdtI

*

Fuel Regression Rate

Fuel Mass Flow Rate

Chamber Pressure

Thrust Coefficient

Thrust

Specific Impulse

Characteristic Exhaust Velocity

f

o

m

mCC

**

Specific Heat Ratio

f

o

m

m

Thermochemical Model: This is Rocket Science

Hybrid Rocket Motors

O/F Ratio

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

1.12

1.14

1.16

1.18

1.20

1.22

1.24

1.26

1.28

1.30

1.32

O/F Ratio

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

C*(

m/s

)

1450

1500

1550

1600

1650

1700

1750

1800

1850

HmOmOmOHmHmCOmOHmCOmOM

M

m

mOHC HooOHHCOOHCO

f

ox

f

ox

22222058.982.10337.7 2222

f

o

m

m

f

o

m

mCC

**

Ab

solid fuelAp

Liquid oxidizer omfr

fm

AtAe

Pc

m

Tc, Xi,

Ab

solid fuelAp

Liquid oxidizer omfr

fm

AtAe

Pc

m

Tc, Xi,

The NASA CEA Chemical Equilibrium computer code was used to calculate Tc, , MW, C* and Xi as a function of oxidizer to fuel ratio.

fuel + oxidizer products + energy

Theoretical Model Results

Hybrid Rocket Motor Design Project

The detailed analytical model was used to predict the variation in fuel flow rate, O/F ratio, chamber pressure, thrust and specific impulse (Isp)

with time.

Ab

solid fuelAp

Liquid oxidizer omfr

fm

AtAe

Pc

m

Tc, Xi,

Ab

solid fuelAp

Liquid oxidizer omfr

fm

AtAe

Pc

m

Tc, Xi,

time (s)

0 5 10 15 20 25 30

Spe

cific

Im

puls

e [s

]

175

180

185

190

195

200

time (s)

0 5 10 15 20 25 30

Thr

ust

[lbf]

4

5

6

7

8

time (s)

0 5 10 15 20 25 30

Cha

mbe

r P

ress

ure

[psi

a]

85

90

95

100

105

110

The theoretical hybrid rocket motor model was also used iteratively optimize their final design to choose the following parameters:

fuel grain length

port diameter

throat diameter

nozzle area ratio

nozzle exit diameter

Concept Design and Parametric Design

The Hybrid Rocket Motor Design Project

Final design drawings were generated for the combustion chamber and the supersonic nozzle using Solid Works.

GOX

HTPB/Al graphitealuminum

L

dp dt de

Fabrication

The Hybrid Rocket Motor Design Project

Combustion chambers were fabricated from aluminum round stock using manual lathes

Supersonic nozzles were fabricated from graphite using a CNC turning center

Fuel Formulation

The Hybrid Rocket Motor Design Project

Hydroxyl Terminated Polybutadiene (HTPB) was formulated, mixed with aluminum particles and cured.

Other fuels such as PMMA, HDPE and UHMW were machined from solid round stock

Mass flow rate was measured and controlled using a Teledyne Hastings HFC203 Mass Flow Controller.

Thrust was measured using an Omega LC101-25 load cell.

Chamber pressure was measured using an Omega Pressure Transducer.

Development of the Hybrid Rocket Motor Test Stand

The Hybrid Rocket Motor Design Project

Thrust Chamber

Nozzle

Load Cell

Igniters

Linear Bearing

Pressure Transducer

Solenoid Valve GOXMass FlowController

The Objective: Deliver a hybrid rocket motor test stand capable of measuring thrust (0-10 lb), chamber pressure (0-250 psig), oxygen mass flow rate (0-500 SLPM)

The Team: Two senior mechanical engineering students, one junior mechanical engineering student and one senior electrical engineering student.

The ignition system consists of dual automotive spark plugs which are energized using an ETP 300ST solid state induction coil

Development of the Hybrid Rocket Motor Test Stand

The Hybrid Rocket Motor Design Project

Igniters

Pressure Transducer

Flow Controller Solenoid Valve

Check Valve

Development of the Hybrid Rocket Motor Test Stand

The Hybrid Rocket Motor Design Project

Load CellLinear Bearing

Data Acquisition

The Hybrid Rocket Motor Design Project

Data acquired included:

instantaneous chamber pressure,

thrust,

oxygen mass flow rate and

high speed dynamic chamber pressure

The data were acquired using an Agilent 34970A Data Acquisition Unit with GPIB interface and an HP 54645D digital storage oscilloscope

With these data, each team was able to measure specific impulse (Isp), characteristic exhaust velocity (C*) and thrust coefficient (CF) and compare these measurements to their analytical models.

Test Firing (HTPB/20% AL/GOX)

The Hybrid Rocket Motor Design Project

Test Firing (Big Red)

The Hybrid Rocket Motor Design Project

Experimental Results

The Hybrid Rocket Motor Design Project

Time [s]

0 5 10 15 20 25

Thr

ust

[lb]

0

2

4

6

8

10

F (Calculated)F (Measured)

Cha

mbe

r P

ress

ure

[psi

g)

0

20

40

60

80

100

Pc (Calculated)

Pc (Measured)

The analytical models reproduced the experimental data reasonably well.

When the variation in actual oxygen mass flow rate was taken into account, analytical results matched the experiments very well!

Ongoing Work

The Hybrid Rocket Motor Design Project

The system is now being used for a research project on the effect of fuel type on combustion instability of hybrid rocket motors.

Conclusions

The Hybrid Rocket Motor Design Project

At the beginning of the semester, students showed very little awareness of the space program and its significance (both historic and contemporary).

This condition is surprising to the generation who grew up wanting to be astronauts.

The hybrid rocket design project was successful in introducing a new generation of students to rocket science.

The hybrid rocket motors were inexpensive, relatively easy to build and safe.

The hybrid rocket motor test stand was an effective junior/senior level design project. Total project cost was approximately $2000.

The test stand is now being used for scholarly pursuits.

Is this valve open?

The Hybrid Rocket Motor Design Project