Hot-Fire Rocket Pump Test

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Hot-Fire Rocket Pump Test


[SIZE=-2]See page for photos and video[/SIZE]


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Pump FAQ


Pump Applications:


Space Tourist Vehicle


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Many space tourist operators plan to use pressure fed systems. The pistonless pump system offers increased performance and greater safety over pressure fed systems because the passengers will not need to sit next to large heavy tanks full of high pressure rocket fuel.

Launch vehicle


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Launch vehicles use turbopumps which are expensive, difficult to design and difficult to test. In fact the space shuttle main engine turbopump has never been tested to it limits beacuse it must be tested while bolted to the engine. This makes estimating its reliability difficult. The pistonless pump is easy to design, build and test and the operating margin and reliability are easy to quantify. A pistonless pump may be tested on the pad before launch without lighting the engine.

In-Space Propulsion


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In space propulsion systems generally use pressure fed systems. These systems require heavy high pressure tanks with propellant management devices to keep the propellant near the outlet. With the pistonless pump, the tanks can be much lighter (up to 4x) because they will run at lower pressure. They can even be made of plastic for material compatibility and light weight.

Opportunity:
We have developed a flexible, safe, reliable, low cost rocket fuel pump which has better performance than turbopump or pressure fed systems. The fuel and oxidizer pump system is the most difficult and time consuming part of a liquid fuel launch vehicle. Thie Flometrics Pistonless Pump will open up new markets for launch vehicles and spacecraft by increasing the safety and performance of propulsion systems. All of today's large launch vehicles use turbopumps which are very expensive to design, build, test and tune. In fact, Beal Aerospace tried to avoid the issue entirely by building a huge pressure fed booster. Their booster never flew, but the engineering behind it was sound, and if they had a high performance pump at their disposal, they might be competing against Boeing and Lockheed Martin.

The pump will also increase the performance and capability of in-space propulsion systems such as will be required for the crew exploration vehicle(CEV), by allowing for greater fuel capacity for a given tank mass and higher engine pressures. (see pressure fed mass savings calculations 101 KB .pdf)

Now Seeking Customers:


Initial pump development is complete, so now we are seeking customers that can define their particular pump requirements, in terms of weight, flow rate ,pressure, burn time, testing and documentation. Contact us for a free Flometrics Pistonless Pump evaluation for your vehicle, including estimates of size, weight and cost, advice on how to integrate the pump with your vehicle and engine and a free DVD video of the pump in operation.

Problem: Pumps for rockets are difficult.

The typical launch vehicle uses a turbopump to pump the fuel into the rocket engine at high pressure. Turbopumps take a long time to develop because they require as hard to develop as a jet engine, but they only run for minutes between overhauls. Also each turbopump must be tuned to a particular rocket thrust chamber, and rocket testing is dangerous and expensive. According to a study done by Boeing, the Space Shuttle has a .1% chance of blowing up due to an engine failure and the turbopumps are the least reliable part of the engine.

Solution: The Flometrics Pistonless Pump
We have designed, built and tested a simple, lightweight pump for use in liquid propelled rockets 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 10. The pump has been tested with a rocket engine and the pump worked perfectly. It has also been tested pumping liquid nitrogen at high pressure, so it can work with LOX. Pump models designed for engines up to 30,000 lbs thrust have been designed and tested. One Pistonless pump can work with many different rocket engines so integration and test are simplified.

How it works:
Rocket engines require a tremendous amount of fuel at high pressure. One way to supply fuel is to use the expensive turbopump mentioned above, another way is to pressurize the entire fuel tank. Pressurizing a large tank requires a heavy, expensive tank. However, suppose instead of pressurizing the 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 about ½ of each cycle. The pump is powered by pressurized gas which acts directly on the fluid. For each half of the pump system, a chamber is first 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 the 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. (See Figure 1 below) A bread board pump has been tested and it works great. A high pressure version has been designed and built and is pumping at 100+ gpm and 550+ psi.



^ Figure 1 Pistonless Pump Diagram (click to animate)

Advantages:
Nearly all of the hardware in this pump consists of pressure vessels, so the weight is low. There are less than 10 low precision moving parts, and no lubrication issues which might cause problems with other pumps. The design and construction of this pump is straightforward and no precision parts are required. This pump has the advantage over standard turbopumps in that the weight is about the same, the unit, engineering and test costs are less and the chance for catastrophic failure is negligible. This pump has the advantage over pressure fed designs in that the weight of the complete rocket is much less, and the rocket is much safer because the large tanks of rocket fuel do not need to be at high pressure. The pump can be started after being stored for an extended period with high reliability. It can be used to replace turbopumps for rocket booster operation 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. A launch vehicle could be built which uses liquid helium to power the pump and this system would require less than 1% of the mass to run the pump as compared to 2-3% for a turbopump system. The liquid helium system was used on the lunar lander, so it is already man-rated.
Performance Validation:
A calculation (120 KB .pdf) of the weight of this type of pump shows that the thurst to weight ratio would be about 160 for a low performance engine. 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. The rocket engine itself could be a low cost ablative design, as in the NASA Fastrac, Scorpius rocket or in recent TRW rocket engine tests. The pump can also work with regen engines from Orion, Rocketdyne, Aerojet, Pratt & Whitney or or even surplus thrust chambers from legacy systems. A typical installation is shown in Figure 2 below.

^ Figure 2 Pistonless Pump Rocket Layout


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.

^ Figure 3.First generation 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.

^ Figure 4. High Pressure and Cryo Compatible Prototype

A video of the pump in action is also available.

The pressure output 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 p21- p22 and to one patented by Sobey,(3,213,804) Jim Blackmon and Eric Lanning (6,314,978) A second generation version (patent allowed) that is lower in weight (12 hp/lb) has been designed and built and is now being tested. The first prototype shown in Figure 5 is designed to work with our Atlas Vernier. It provides 20 GPM at 600+ psi and it is made of stainless steel, brass and Teflon to be compatible with all common rocket fuels(LOX,RP-1, H2O2, hydrazine etc). Test results are in the papers on the left.

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 achieve an altitude of over 100 miles (Rocksim Results)
For more information or to get a quote for a pump for your application, contact Steve Harrington, Ph.D.​