A

SEMINAR REPORT ON

PISTONLESS PUMP FOR ROCKET

SUBMITTED TO THE UNIVERSITY OF PUNE,PUNE

IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE

AWARD OF THE DEGREE OF

B.E(MECHANICAL ENGINEERING)

BY

PUJAN N. SHAH

EXAM. NO. B221O864 ROLL NO: 4162

A.I.S.S.M’S

COLLEGE OF ENGINEERING

KENNEDY ROAD, SHIVAJINAGAR, PUNE-01

CERTIFICATE

THIS IS TO CERTIFY THAT SENINAR ENTITLED

PISTONLESS PUMP FOR ROCKET

SUBMITTED BY

PUJAN NARENDRA SHAH

EXAM NO. B2210864 ROLL NO : 4162

For the partial fulfillment of curriculum

Of degree of B.E.mech.

University of pune.

2003-2004

Prof: Mrs. S.V.Phadkule Prof: V.N. Phadkule

Guide Head of Department

MECHANICAL ENGG.DEPT. MECHANICAL ENGG.DEPT.

Date:

ACKNOWLEDGEMENT:

It gives me immense pleasure to present before you this

Seminar.

First and for the most,I wish to record my deep gratitude and thanks

to Prof: Mrs. S.V.Phadkule for her enthusiastic guidance and

help in successful completion of her kind of support.

It is a great pleasure for me to acknowledge the assistance and

contribution of the number of individuals who helped me in

presentation.

SHAH PUJAN N.

B.E.MECH.

INDEX

SR NO. TOPICS PAGE NO.

1} INTRODUCTION 1

2} NECESSITY 2

3} DUAL PISTONLESS PUMP 2

4} WORKING OF THE PUMP 3

5} DIAGRAM OF PISTONLESS PUMP 4

6} ADVANTAGES 6

7} APPLICATIONS 7-8

8} PERFORMANCE VALIDATION 9

9} ISTALLATION IN ROCKET 10-11

10} WORKING MODELOF THE PUMP 12-13

11} GRAPH OF FLOW RATE VS. TIME 14-15

12} DISADVANTAGES 16

13} COCLUSION 17

14} BIBLOGRAPHY 18

ABSTRACT:

Pistonless pump for rocket has been proved to be the most economical than piston pump or turbopump.

In pistonless pumps, piston is absent. It has very much less rotating parts than that of piston pumps or turbo pumps. So, it has less friction losses and there by it helps to improve the efficiency of the engine considerably.They can be easily installed in the rocket than turbopumps.Also,it reduces the weight of rocket.

This article discusses the working , advantages of pistonless pump over turbopump.

Pistonless pumps are 80-90% economical than that of piston pump or turbo pumps.Nasa has manufactured such kind of pump and tested it actually,and they found it works conveneiently.

INTRODUCTION:

NASA have developed a Low cost rocket fuel pump which has

Comparable performance to turbopump at 80-90% lower cost. Perhaps

the most difficult barrier to entry in the liquid rocket business is the

turbo pump. A turbo pump design requires a large engineering effort

and is expensive to mfg. and test. Starting a turbo pump fed rocket

engine is a complex process, requiring a careful of many valves and

subsystems.In fact ,Beal aerospace tried to avoid the issue entirely by

building a huge pressure feed booster. Their booster never flew, but the

engineering behind it was sound and ,if they had a low cost pump at

their disposal ,they might be competing against Boeing. This pump

saves up to 90% of the mass of the tanks as compared to a pressure

fed system. This pump has really proved to be a boon for rockets . By

this pump the rocket does not have to carry heavy load and can travel

with very high speed.

NECESSECITY:

The turbo pumps used in rocket are very heavy,containing many

rotating parts by which there are more frictional losses which

more consumption of fuel there by decreasing the efficiency of

the engine .Also, the maintainanace of such pump is, very

important factor since the rocket has to remain stable in the

space, is difficult and require complex methods for it. If this

pump gets any fault then its repairance requires long time and also

it is avery hectic task.So, there must be such a device which

overcomes all the drawbacks of the turbopump as above. The

pistonless pump is the solution for the problems faced by using

turbopumps. They have only a drawback that they supply fuel

with less pressure as compared to turbopumps.

THE DUAL PISTONLESS PUMP:

NASA has designed,built and tested a simple, light weight pump

(dual pistomless pump) for use in liquid propelled rocket where a

reliable pump with minimal moving parts is needed. This pump

has the potential to reduce the cost and increase the reliability of

rocket fuel pumps by a factor of 20 to 100.

WORKING:

Rocket engines requires a tremendous amount of fuel high

at high pressure .Often th pump costs more than the thrust

chamber.One way to supply fuel is to use the expensive

turbopump mentioned above,another way is to pressurize fuel

tank. Pressurizing a large fuel tank requires a heavy , expensive

tank. However suppose instead of pressurizing entire tank, the

main tank is drained into a small pump chamber which is then

pressurized. To achieve steady flow, the pump system consists of

two pump chambers such that each one supplies fuel for ½ of

each cycle. The pump is powered by pressurized gas which acts

directly on fluid. For each half of the pump system, a chamber is

filled from the main tank under low pressure and at a high flow

rate, then the chamber is pressurized, and then the fluid is

delivered to the engine at a moderate flow rate under high

pressure. The chamber is then vented and cycle repeats. The

system is designed so that the inlet flow rate is higher than the

outlet flow rate.This allows time for one chamber to be vented ,

refilled and pressurized while the other is being emptied.A bread

board pump has been tested and it works great .A high version

has been designed and built and is pumping at 20 gpm and 550psi.

PISTONLESS PUMP FIGURE:

As shown in the above diagram , two cylinders are there ,

filled with the fuel from the main tank. This main tank is

emptied in these two cylinders, these cylinders are

pressurized by the high pressure tank,as shown.The high

pressure tank pressurizes one cylinder of high pressure,as

shown,as soon as the cylinder is emptied , it is vented,

again it gets filled up from the main tank.The same cycle

reapeats for the second cylinder.the cycle is such that,

fuel is supplied by the cylinder one by one.ie. each

cylinder supplies fuel for each half cycle.As one cylinder

supplies the fuel other has enough time to refill.

ADVANTAGES:

Nearly all of the hardware in this pump consists of pressure

vessels, so the weight is low.There are less than 10 moving parts ,

and no lubrication issues which might cause problems with other

pumps. The design and constr. Of this pump is st, forward and no

precision parts are required .This device has advantage over std.

turbopumps in that the wt. is about the same, the unit,engg.and test

costs are less and the chance for catastrophic failure is less.This

pump has the advantage over pressure fed designs in that the wt. of

the complete rocket is much less, and the rocket is much safer

because the tanks of rocket fuel do not need to be at high pressure.the

pump could be started after being stored for an extended period with

high reliability.It can be used to replace turbopumps for rocket

booster opn. or it can be used to replace high pressure tanks for deep

space propulsion.It can also be used for satellite orbit changes and

station keeping.

APPLICATIONS:

1}DEEP SPACE PROPULSION :

NASA has a need for high power propulsion to land and

spacecraft on the moons of Jupitor and beyond.this pump would

allow these missions to go forward due to lower weight of the fuel

tanks. For example, to land on Europa with a hydrazine

monopropellant rocket , pump fed design would save 80% of the

tank weight compared to a pump fed design.Further weight

savings could be achieved by heating the pressurant gas more,

because the pressurant would not be in contact with the propellant

for more than a few seconds . In addition ,the chamber could be

increased , saving engine weight and improving performance.

2} X PRIZE VEHICLE FUEL PUMP APPLICATION:

For X-prize competitors, a the fuel pump will reduce the cost

and increase the safety and reliability of their amateur manned

vehicles.Sitting on top of tons of rocket fuel is dangerous

enough,siiting on top if tons of rocket fuel at high pressure is

even more so. Many of the competitors plan to use Hydrogen

Peroxide(HTP) and jet fuel to power their rockets.When the

pump is used to pump HTP, it can decompose some of the fuel in

a gas generator to run the pump. This saves a considerable

amount of weight pressurant and main tankage.

In addition , the factor on the low pressure tanks will

be similar to the cost of the high pressure tanks alone.

PERFORMANCE VALIDATION:

A calculation of the weight of this type of pump shows that the

power to weight ratio would be dominated by the pressure chamber

and that it would be of the order of 8-12 hp per lb., for a 5 second

cycle using a composite chamber. This performance is similar to

state of the art gas-generator turbopump technology. (The F1

turbopump on the Saturn V put out 20 hp/lb) This pump could be

run until dry, so it would achieve better residual propellant

scavenging than a turbopump. This system would require a supply

of gaseous or liquid Helium which would be heated by a heat

exchanger mounted on the combustion chamber before it was used

to pressurize the fuel, as in the Ariane rocket.. The volume of

gas required would be equivalent to a standard pressure fed design,

with a small additional amount to account for ullage in the pump

chambers. The rocket engine itself could be a primarily ablative

design, as in the NASA Fastrac, scorpious rocket or in

recent rocket engine tests.

INSTALLATION FIGURE:

A proof of concept model of the pump has been constructed out of clear

plastic and tested at low pressure. The results of the test are shown below.

The pressure and flow are quite steady. The pump system is run with a

Labview based computer program. There are two floats which are used to

monitor the level in each pump chamber and each chamber uses

a two solenoid valves, one to pressurize source and on to vent the chamber.

The installation figure of the pistonless pump is shown in the above figure.

The high pressure cylinder used for pressurizing fuel,is installed at the

bottom of the rocket,shown in green colour in the figure.And above this

cylinder further assembly is mounted as shown in the first diegram.

Thus the figure shows that the installation is very easy as compared to that

of the turbo pump.

WORKING MODEL OF ROCKET FUEL PUMP:

The pump shown is equipped with electronic level sensors and air cylinder

actuated ball valves. The pump works as predicted and it will be easy to

reconfigure it to pump LOX and jet fuel.this type of pump will make rocket

propulsion systems much more reliable and less expensive than that of the

turbo jet pump.

FLOW AND PRESSURE DATA FOR ROCKET FUEL PUMP:

The above graph shows the variation of the flow of fuel through

both of the cylinders .It shows that as one cylinder gets emptied the

other one gets filled up and fuel is supplied by each cylinder to

the engine for each half cycle. As one cylinder gets emptied the

other one gets filled up , thus giving an uninterrupted fuel supply

to the engine. Also, the time required for the refill of the fuel in

the cynlinder is sufficient to supply fuel for next half cycle.

A video of the pump in action is also available.The is steady as well

and as the design is improved, the flow and pressure will be

steadier. This pump is similar to one mentioned in 1960 in

Exploring the Solar System by Felix Godwin p-21 p-22 and to one

patented by Sobey,(3,213,804) Jim Blackmon and Eric Lanning

(6,314,978) A second generation version (patent pending) that is

lower in weight (12 hp/lb) has been designed and built and is now

being tested. The first prototype is designed to work with our Atlas

Vernier. It provides 20 GPM at 600+ psi and it is made of stainless

steel and Teflon to be compatible with all common rocket

fuels(LOX,RP-1, H2O2, hydrazine etc). Check this page soon for

test results. We plan to build a couple of flight ready versions of

this pump to pump LOX and kerosene and fly it on one of our

Atlas vernier powered rockets This rocket will be able to acheive an

altitude of over 100 miles

DISADVANTAGES:

The pistonless pumps has disadvantages along with such fine advantages.

1}They cannot pump to higher pressure than drive gas (area ratio is 1:1)

2}They cannot use either a staged combustion or expander cycle.

3}A gas generator cycle is also difficult to integrate with the pistonless pump.

4}The generated gas must be chemically compatible with both the propellants.

5}This gas generator lowers the Ignition start period of the engine.

CONCLUSION:

The most significance of property of Pistonless pump that makes them different from that of turbo pump ,is the absence of piston.

This is the most unique technique.In this ,no. of rotating parts is very less as compared to that of turbopump. Also, it’s installation is very easy.and moreover, it is light weight than turbo pump.So, it has less losses and improves,rather increases efficiency of engine.Also, it is much economical than turbopump.

The only drawback of pistonless pump is that, that it cannot supply high pressure fuel and also,it cannot have stage combustion or expander cycle,further, it has no vibrations.

BIBLOGRAPHY:

1}Theory Of Rocket propulsion (By R.H.Boden)

2}Book Of Rocket Propulsion (By zechosloviky)

3}Mechanics Of Thermodynamics Of propulsion

(By Philip Hill,Call Peterson)

4}http://www.kahuna.sdsu.edu

5}www.flowmetrics.com

6}www.xcor.com