US-12618623-B2 - Dynamic ram accelerator system

Abstract

Dynamic ram accelerator operation permits operation with lower acceleration, permitting launch of acceleration sensitive payloads such as crewed vehicles. Operational cost is reduced, and reliability improved, by reducing or eliminating internal consumable parts. Relative motion between a projectile and propellant at entry to the ram accelerator enables initial ram combustion at relatively lower velocity. Valves may maintain separation between sections within the ram accelerator that contain different propellant compositions. Timing of valve opening and closing is coordinated to provide conditions suitable for ram combustion. Control over propagation speed of propellant within the system may be obtained using one or more of baffle shape, baffle spacing, propellant temperature, propellant pressure, propellant mixture, temperature of components such as baffles, and so forth. Before the projectile is launched, internal separators between sections are removed, providing an open path to the ram accelerator exit.

Inventors

• Mark C. Russell

Assignees

• PIPELINE2SPACE, INC.

Dates

Publication Date

20260505

Application Date

20230626

Claims (20)

1. 1 . A system comprising: a pre-launch system comprising; a launch tube having a launch tube entry and a launch tube exit; a ram accelerator system comprising: a first section having a first end and a second end, wherein the first end is proximate to the launch tube exit; a second section having a third end and a fourth end, wherein the third end is proximate to the second end; a first fill stage having a fifth end and a sixth end, wherein the fifth end is proximate to the second end and the sixth end is proximate to the third end; a first valve between the fifth end and the second end; and a second valve between the sixth end and the third end; a gas control system; and a control system in communication with the pre-launch system and the ram accelerator system, the control system to: operate the first valve and the second valve to close at a first time; operate the gas control system to fill the first fill stage with a first gas at a second time, wherein the second time is after the first time; operate the first valve to open after the second time; operate the second valve to open after the second time; and after opening the first valve and the second valve, initiate operation of the pre-launch system to launch a projectile, wherein: the projectile is launched such that as the projectile enters the first section, the first gas moves in a direction that is opposite to the projectile and past the projectile, resulting in a first relative velocity of the first gas with respect to the projectile that is a sum of a velocity of the first gas and a velocity of the projectile, and the projectile is launched such that as the projectile enters the second section, the first gas moves in a same direction as the projectile, resulting in a second relative velocity of the first gas with respect to the projectile that is a difference between the velocity of the first gas and the velocity of the projectile.
2. 2 . The system of claim 1 , further comprising an exit diaphragm proximate to an exit of a section of the ram accelerator system to a surrounding environment, wherein the exit diaphragm is penetrated by the projectile.
3. 3 . The system of claim 1 , wherein the first section is evacuated before initiation of the pre-launch system to launch the projectile.
4. 4 . The system of claim 1 , wherein the first section contains the first gas before initiation of the pre-launch system to launch the projectile.
5. 5 . The system of claim 1 , wherein one or more of the first section or the second section are at a specified temperature before initiation of the pre-launch system.
6. 6 . The system of claim 1 , wherein the first gas is at a specified temperature before initiation of the pre-launch system.
7. 7 . The system of claim 1 , the ram accelerator system comprising at least one baffle tube section comprising a plurality of baffles.
8. 8 . The system of claim 1 , the ram accelerator system comprising a plurality of baffles and a plurality of rails, wherein the plurality of rails are mechanically engaged to the plurality of baffles and the rails constrain movement of the projectile within the ram accelerator system.
9. 9 . The system of claim 1 , the pre-launch system further comprising: the gas control system to provide pressurized gas to the launch tube; a third valve proximate to the launch tube entry, wherein the third valve is operable to provide an opening with a time-variable cross-sectional area between the gas control system and the launch tube; and the control system to: operate the third valve to provide: a first specified mass flow of launch gas through the third valve and into the launch tube at a third time, and a second specified mass flow of launch gas through the third valve and into the launch tube at a fourth time.
10. 10 . The system of claim 1 , the projectile comprising a space vehicle.
11. 11 . The system of claim 1 , wherein the projectile is stationary prior to the projectile being launched.
12. 12 . A system comprising: a pre-launch system comprising; a launch tube having a launch tube entry and a launch tube exit; a ram accelerator system comprising: a first section having a first end and a second end, wherein the first end is proximate to the launch tube exit; a second section having a third end and a fourth end, wherein the third end is proximate to the second end; a first fill stage having a fifth end and a sixth end, wherein the fifth end is proximate to the second end and the sixth end is proximate to the third end; a first valve between the fifth end and the second end; a second valve between the sixth end and the third end; and a plurality of baffles within one or more of the first section, the second section, or the first fill stage; a gas control system; and a control system in communication with the pre-launch system and the ram accelerator system, the control system to: operate the first valve and the second valve to close at a first time; operate the gas control system to fill the first fill stage with a first gas at a second time, wherein the second time is after the first time; operate the first valve to open after the second time; operate the second valve to open after the second time; and operate the pre-launch system to launch a projectile, wherein: the projectile is launched such that as the projectile enters the first section there is a first relative velocity between the first gas and the projectile, the projectile is launched such that as the projectile enters the second section there is a second relative velocity between the first gas and the projectile, and the second relative velocity is less than the first relative velocity.
13. 13 . The system of claim 12 , wherein as the projectile enters the first section, the first gas moves opposite to and past the projectile, resulting in the first relative velocity between the first gas and the projectile that is a sum of a projectile velocity and a gas velocity.
14. 14 . The system of claim 12 , wherein as the projectile enters the second section, the first gas moves in a same direction as the projectile, resulting in the second relative velocity between the first gas and the projectile that is a difference between a projectile velocity and a gas velocity.
15. 15 . The system of claim 12 , further comprising an exit diaphragm proximate to an exit of a section of the ram accelerator system to a surrounding environment, wherein the exit diaphragm is penetrated by the projectile.
16. 16 . The system of claim 12 , wherein the first section is evacuated before initiation of the pre-launch system to launch the projectile.
17. 17 . The system of claim 12 , wherein the first section contains the first gas before initiation of the pre-launch system to launch the projectile.
18. 18 . The system of claim 12 , wherein one or more of the first section or the second section are at a specified temperature before initiation of the pre-launch system.
19. 19 . The system of claim 12 , wherein the first gas is at a specified temperature before initiation of the pre-launch system.
20. 20 . The system of claim 12 , the ram accelerator system comprising a plurality of rails, wherein the plurality of rails are mechanically engaged to the plurality of baffles and the rails constrain movement of the projectile within the ram accelerator system.

Description

PRIORITY This application claims priority to, and the benefit of, U.S. Provisional Patent Application Ser. No. 63/367,096 filed on 27 Jun. 2022, titled “DYNAMIC RAM ACCELERATOR SYSTEM”, the contents of which are hereby incorporated by reference into the present disclosure. This application claims priority to, and the benefit of, U.S. Provisional Patent Application Ser. No. 63/367,188 filed on 28 Jun. 2022, titled “RAM ACCELERATOR SYSTEM”, the contents of which are hereby incorporated by reference into the present disclosure. COMPUTER PROGRAM LISTING APPENDIX This disclosure incorporates by reference the material submitted in the Computer Program Listing Appendix filed herewith. The material within the Computer Progra1m Listing Appendix is Copyright 2022 to Mark Russell, all rights reserved. The Computer Program Listing Appendix is expressed in the GNU Octave language as promulgated at gnu.org/software/octave. BACKGROUND Traditional ram accelerators have limited operational regimes that constrain operation. These constraints have precluded various operations such as delivering payloads that are sensitive to high shock accelerations, such as passengers and satellites. BRIEF DESCRIPTION OF FIGURES The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items or features. The figures are not necessarily drawn to scale, and in some figures, the proportions or other aspects may be exaggerated to facilitate comprehension of particular aspects. For ease of discussion, and not necessarily as a limitation unless otherwise indicated, “upstream” refers to a direction away from the exit of the ram accelerator while “downstream” refers to a direction towards the exit of the ram accelerator system. For ease of discussion, and not necessarily as a limitation unless otherwise indicated, a section separator mechanism that provides a barrier to movement of a gas between sections may be referred to as a “valve”. In some implementations the valve may be reusable, such as with a ball valve, clamshell valve, gate valve, and so forth. In other implementations the valve may comprise a frangible diaphragm (stationary or moveable) or single-use device. Valves may be mechanically, pneumatically, electrically, magnetically, chemically, pyrotechnically, and otherwise operated. FIG. 1 illustrates a dynamic ram accelerator system, according to some implementations. FIG. 2 illustrates some portions of a dynamic ram accelerator, according to some implementations. FIG. 3 illustrates an enlarged view of a portion of a dynamic ram accelerator and the relative velocity between gas flow and projectile at various portions, according to some implementations. FIG. 4 illustrates a first implementation of operation of a dynamic ram accelerator system. FIG. 5 illustrates a second implementation of operation of a dynamic ram accelerator system with one or more additional gas reservoirs. FIG. 6 illustrates a third implementation of operation of a dynamic ram accelerator system with a moveable diaphragm. FIGS. 7-8 depict implementations of a baffle tube section with rails, according to some implementations. While implementations are described herein by way of example, those skilled in the art will recognize that the implementations are not limited to the examples or figures described. It should be understood that the figures and detailed description thereto are not intended to limit implementations to the particular form disclosed but, on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to. DETAILED DESCRIPTION A ram accelerator is used to accelerate a projectile. This projectile may comprise an inert object, or a payload such as a vehicle. For example, the payload may comprise a space vehicle that is crewed or uncrewed. Some payloads are sensitive to high accelerations, such as satellites or human crew and passengers. To provide sufficient velocity to enter orbit, traditional ram accelerator designs would impose accelerations too great causing damage to these sensitive payloads. A ram accelerator operates with a projectile having an initial velocity relative to the gas it is moving through. The gas may comprise a single gas or a mixture of different gases. At the ram accelerator initial velocity, the