Feed system and a method of suppressing the POGO effect

Patent metadata

Field	Value
Publication number	US-9528470-B2
Application number	US-201214118369-A
Country	US
Kind code	B2
Filing date	May 7, 2012
Priority date	May 17, 2011
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A rocket engine feed system, includes a feed circuit including a device for varying a gas volume in the feed circuit to suppress the POGO effect. A method of suppressing the POGO effect varies at least one hydraulic resonant frequency by varying a rate at which gas is injected into the feed circuit.

First claim

The invention claimed is:

1. A feed system for feeding a rocket engine with a liquid propellant, the system comprising:
a feed circuit; and
a device to vary a volume of gas in the feed circuit, which device is configured to cause a volume of gas in the feed circuit to vary while the rocket engine is in operation,
wherein the device to vary the volume of gas comprises a hydraulic accumulator with a variable liquid level, the hydraulic accumulator including a plurality of dip tubes, each including a respective valve and connecting a duct of the feed circuit to a respective distinct liquid level, wherein each dip tube extends to a surface of the liquid at their respective distinct liquid level.

2. A feed system according to claim 1 , further comprising a control unit configured to control the device to vary gas volume.

3. A feed system according to claim 2 , further comprising at least one sensor connected to the control unit, and wherein the control unit is configured to control variation in the gas volume as a function of signals sensed by the at least one sensor.

4. A feed system according to claim 3 , wherein the at least one sensor comprises an accelerometer.

5. A feed system according to claim 3 , wherein the at least one sensor comprises a sensor to sense pressure of the propellant.

6. A feed system according to claim 2 , wherein the control unit is configured to control variation of the gas volume as a function of time.

7. A vehicle comprising a rocket engine including a liquid propellant having a feed system according to claim 1 .

8. A method of suppressing a POGO effect, comprising:
varying a volume of gas in a feed circuit of a system to feed a rocket engine with a liquid propellant while the rocket engine is in operation, to control a difference between at least one hydraulic resonant frequency of the feed circuit and at least one mechanical resonant frequency of a structure coupled to the feed circuit,
wherein the variable gas volume is located at least in part in a hydraulic accumulator connected to a duct of the feed circuit and including a plurality of dip tubes, each including a respective valve and connecting the duct to a respective distinct liquid level, wherein each dip tube extends to a surface of the liquid at their respective distinct liquid level.

9. A method of suppressing the POGO effect according to claim 8 , wherein the gas volume varies to keep the difference above a predetermined threshold.

10. A method of suppressing the POGO effect according to claim 8 , wherein the gas volume is caused to vary as a function of at least one mechanical oscillation value sensed on the structure.

11. A method of suppressing the POGO effect according to claim 10 , further comprising performing spectral analysis on at least one mechanical oscillation to determine the at least one mechanical resonant frequency of the structure.

12. A method of suppressing the POGO effect according to claim 11 , wherein a filter algorithm, or an unscented Kalman filter, is applied to at least one sensed mechanical oscillation to determine the at least one mechanical resonant frequency and/or to predict its future variation.

13. A non-transitory computer readable medium including computer executable instructions for performing a method of suppressing the POGO effect according to claim 8 .

Assignees

• Kernilis Alain
• Lemoine Nicolas
• Boulet Ludivine
• Le Gonidec Serge
• Snecma
• Centre Nat D'Etudes Spatiales Cnes

Inventors

• Kernilis Alain
• Lemoine Nicolas
• Boulet Ludivine
• Le Gonidec Serge

Classifications

• F05D2270/54

  by electronic means, e.g. electronic tubes, transistors or IC's within an electronic circuit · CPC title

• F02K9/60

  Constructional parts; Details not otherwise provided for · CPC title

• F02K9/566 Primary

  elements and safety devices, e.g. pressure relief valves · CPC title

• F05D2270/44

  active, predictive, or anticipative · CPC title

• F02K9/96

  characterised by specially adapted arrangements for testing or measuring · CPC title