CN117052566A - Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine - Google Patents
Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine Download PDFInfo
- Publication number
- CN117052566A CN117052566A CN202311173046.9A CN202311173046A CN117052566A CN 117052566 A CN117052566 A CN 117052566A CN 202311173046 A CN202311173046 A CN 202311173046A CN 117052566 A CN117052566 A CN 117052566A
- Authority
- CN
- China
- Prior art keywords
- engine
- starting
- overshoot
- time
- relative quantity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 36
- 230000001133 acceleration Effects 0.000 claims abstract description 36
- 239000003721 gunpowder Substances 0.000 claims description 26
- 239000007789 gas Substances 0.000 claims description 22
- 239000007858 starting material Substances 0.000 claims description 17
- 239000003380 propellant Substances 0.000 claims description 8
- 239000002737 fuel gas Substances 0.000 claims description 3
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
- F02K9/95—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof characterised by starting or ignition means or arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
- F02K9/42—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof using liquid or gaseous propellants
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Turbines (AREA)
Abstract
The invention relates to a method for reducing the starting overshoot of an open cycle forced starting high altitude rocket engine; in order to improve the working reliability of the engine, the starting overshoot is reduced or eliminated on the premise of ensuring the starting acceleration; comprises the following steps: defining a primary starting overshoot relative quantity threshold A1 and a secondary starting overshoot relative quantity threshold A2 of the engine rotating speed; step 2: starting the engine once, opening two auxiliary valves at the moment t1, and calculating the relative quantity B1 of the primary starting overshoot of the rotating speed when the starting acceleration of the engine is met; step 3: if B1 is less than A1, executing step 4, otherwise, delaying t1 and returning to step 2; step 4: starting the engine for the second time, opening two auxiliary valves at the moment t2, and calculating the relative quantity B2 of the secondary starting overshoot of the rotating speed when the starting acceleration of the engine is satisfied; step 5: if B2 is less than A2, executing the step 6; otherwise, delaying t2 and returning to the step 4; step 6: t1 and t2 are recorded, so that the open cycle forced start high altitude rocket engine starting overshoot is reduced.
Description
Technical Field
The invention relates to a high-altitude liquid rocket engine, in particular to a method for reducing the starting overshoot of an open-cycle forced starting high-altitude rocket engine.
Background
The high-altitude liquid rocket engine with the multiple starting function adopts a gunpowder starter to perform ignition, drives a turbine to rotate, and is an initial power source for starting the engine. The ignition time of the gas generator is controlled, so that the gas generator and the gunpowder starter work in a combined mode, and after the gunpowder is burnt out, the gas generator works independently, so that the engine is transited to a main-stage working state.
In order to ensure starting acceleration, in the existing starting scheme, an overlapping working interval exists between the gunpowder starter and the gas generator, so that a large overshoot phenomenon exists in the rotation speed of the engine, the working condition is exceeded, and the working load of the assembly is increased. The internal pressure of the assembly pipeline, the thrust chamber and other components is increased, and the stress born by each welding seam is increased; in addition, the turbine rotating speed is greatly increased in the parameter overshoot section, so that the working load of components such as end face seal, bearings and the like is increased, the working condition is more severe, and the working reliability of the engine is adversely affected to a certain extent. Although a large number of flight and test run tests prove that the current starting overshoot cannot influence the normal operation of the engine, the risk is controllable. However, in order to further improve the working reliability of the engine, corresponding measures should be taken to reduce or eliminate the amount of starting overshoot on the premise of ensuring the starting acceleration of the engine.
Disclosure of Invention
In order to further improve the working reliability of the engine, the invention adopts corresponding measures, reduces or eliminates the starting overshoot under the premise of ensuring the starting acceleration of the engine, and provides a method for reducing the starting overshoot of the open-cycle forced starting high-altitude rocket engine.
The technical scheme of the invention is as follows:
the method for reducing the starting overshoot of the open cycle forced starting high altitude rocket engine is characterized by comprising the following steps of:
step 1: defining a primary starting overshoot relative quantity threshold value of the rotating speed of the engine as A1, and defining a secondary starting overshoot relative quantity threshold value as A2;
step 2: one-time starting of engine
When the engine is started once, two auxiliary valves are opened at the time t1, and the relative quantity B1 of the primary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
step 3: if B1 is less than A1, executing step 4 to perform secondary starting of the engine; otherwise, delaying t1 and returning to the step 2;
step 4: secondary start of engine
When the engine is started for the second time, two auxiliary valves are opened at the time t2, and the relative quantity B2 of the secondary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
step 5: if B2 is less than A2, executing the step 6; otherwise, delaying t2 and returning to the step 4;
step 6: t1 and t2 are recorded, so that the open cycle forced start high altitude rocket engine starting overshoot is reduced.
Further, the step 2 specifically includes:
2.1, when the engine is started once, opening two auxiliary valves at the time t 1;
2.2, obtaining starting acceleration of the engine in the current state;
2.3, if the starting acceleration of the engine in the current state meets the requirement, executing the step 2.4, otherwise, returning to the step 2.1, and reducing the time of t1 until the starting acceleration of the engine in the current state meets the requirement, and executing the step 2.4;
and 2.4, calculating a primary starting overshoot relative quantity B1 of the rotating speed of the engine.
Further, the step 2.1 specifically includes:
2.11, before the gunpowder starter of the engine ignites, two component propellants of the engine respectively fill an engine cavity in front of a main valve of the engine and an engine cavity in front of an auxiliary valve, and keep the two auxiliary valves in a closed state;
2.12, starting the gunpowder starter at the moment 0, and rotating the turbine under the pushing of the pressure and flow of the gunpowder gas;
2.13, opening two auxiliary valves at time t1 to enable two component propellants to enter an engine gas generator for ignition, and enabling gunpowder to burn to generate fuel gas to drive a turbine to move;
and 2.14, after the gunpowder is burnt out, the gas generator works independently to continuously drive the turbine, and the starting process of the engine is finished.
Further, the step 4 specifically includes:
4.1, on the premise that the relative quantity B1 of primary starting overshoot of the rotating speed of the engine is less than A1, when the engine is started for the second time, opening two auxiliary valves at the time t 2;
4.2, obtaining starting acceleration of the engine in the current state;
4.3, if the starting acceleration of the engine in the current state meets the requirement, executing the step 4.4, otherwise, returning to the step 4.1, and reducing the time of t2 until the starting acceleration of the engine in the current state meets the requirement, and executing the step 4.4;
and 4.4, calculating the relative quantity B2 of the secondary starting overshoot of the rotating speed of the engine.
Further, the method of starting the engine twice in the step 4.1 is the same as that of starting the engine once in the step 2.1.
The invention has the beneficial effects that:
1. according to the invention, under the condition that the existing structure of the engine is not changed and the development progress is ensured, the overshoot in the starting process of the engine is effectively reduced only by changing the working time of the auxiliary system.
2. In the invention, based on the principle of matching the working relay time and the rotating speed overshoot of the gas generator and the gunpowder starter (the shorter the working relay time is, the smaller the rotating speed overshoot is), the problem of large load of an engine assembly and severe working environment in the starting process caused by the overlarge system starting overshoot is solved.
3. The method provided by the invention can delay the ignition time of the gas generator on the premise of meeting the starting acceleration requirement so as to achieve the purpose of reducing the starting overshoot.
Drawings
FIG. 1 is a schematic diagram of a prior art engine control system;
FIG. 2 is a schematic diagram of a start timing sequence according to an embodiment of the present invention;
FIG. 3 is a graph comparing dimensionless rotation speed curves before and after the method of the present invention is used;
FIG. 4 is a graph comparing turbine start-up overshoot curves before and after the use of the method of the present invention;
in the figure, 1-gunpowder starter, 2-gas generator, 3-auxiliary valve, 4-turbine and 5-pump.
Detailed Description
The three-stage rocket engine system is shown in fig. 1, and comprises a gunpowder starter 1, a gas generator 2, a turbine 4, two auxiliary valves 3 and two pumps 5, wherein the engine has the capacity of two-time starting operation, the starting system is used for driving the turbine to rotate so as to enable the engine to pass through a main stage working state, wherein two L respectively represent a fuel inlet and an oxidant inlet, and G represents an outlet.
The starting process is divided into two phases: the first stage is that the gunpowder starter 1 provides an initial power source, and the turbine 4 is driven to rotate after the ignition of the electric explosion tube. The second stage is to supply the turbine 4 with the propellant from the sub-system (the two sub-valves 3, the gas generator 2 and the piping between them), to maintain the turbine 4 working properly and to continue supplying the propellant to the main system.
By analysing the engine starting process, the overlap between the gunpowder combustion time of the starting system and the working interval of the subsystem providing the supply of working medium of the turbine 4 during ignition is a key factor in the presence of a starting overshoot. The longer the overlap working interval, the greater the amount of overshoot of the starting process, but the better the starting acceleration. To reduce engine start-up overshoot, this may be achieved by: 1. adjusting parameters and structures of the auxiliary system, such as adding measures such as starting a valve to reduce the flow of the auxiliary system in the starting process; 2. the burning speed of gunpowder is reduced or the burning time is shortened; 3. the overlapping working time of the gunpowder starter 1 and the gas generator 2 is shortened.
Adjusting the parameters and structure of the auxiliary system can change the performance and layout of the engine, increase the complexity of the system, require starting simulation analysis and multiple ground test verification and check, and consume a long time. The essence of reducing the charge burn rate or the combustion time is to change the charge loading or the combustion energy of the charge, and the engine start-up acceleration is substantially linear with the charge combustion rate, which may result in a decrease in the engine start-up acceleration. After comprehensive consideration, it is considered that the scheme of reducing the starting overshoot by optimizing the working of the powder starter 1 and the overlapping working area of the gas generator 2 has low improvement risk, easy realization and small influence on the propulsion system, but the changing of the working of the powder starter 1 and the overlapping working area of the gas generator 2 is mainly realized by delaying the relay time of the powder starter 1 and the gas generator 2, which also reduces the starting acceleration of the engine, and can lead to the delayed ignition and even the failure of the starting of the engine under the limit condition. The key point of this improvement is therefore: on the premise of ensuring that the starting acceleration of the engine is not more than the task requirement, the relative quantity of the starting overshoot is reduced to be below a threshold value, namely, the second starting overshoot of the engine is smaller than a preset threshold value in ground test.
Based on the above, the invention provides a method for reducing the starting overshoot of an open cycle forced starting high altitude rocket engine, comprising the following steps:
step 1: defining a primary starting overshoot relative quantity threshold value of the rotating speed of the engine as A1, and determining the starting acceleration of the engine in advance with a secondary starting overshoot relative quantity threshold value as A2;
step 2: one-time starting of engine
When the engine is started once, two auxiliary valves 3 are opened at the time t1, and the relative quantity B1 of the primary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
2.1, as shown in fig. 2, when the engine is started once, two auxiliary valves 3 are opened at the time t 1;
2.11, before the gunpowder starter 1 of the engine ignites, two component propellants of the engine respectively fill an engine cavity before a main valve of the engine and an engine cavity before an auxiliary valve 3, and keep the two auxiliary valves 3 in a closed state;
2.12, starting the gunpowder starter 1 at the moment 0, and rotating the turbine 4 under the pushing of the pressure and flow of the gunpowder gas;
2.13, opening two auxiliary valves 3 at time t1, so that two component propellants enter an engine gas generator 2 to be ignited, gunpowder is combusted, and fuel gas is generated to drive a turbine 4 to move;
2.14, L, after the gunpowder is burnt out, the gas generator 2 works independently to continue to drive the turbine 4, and the engine starting process is completed;
2.2, calculating to obtain the starting acceleration of the engine when the two auxiliary valves 3 are opened at the time t 1;
2.3, if the starting acceleration of the engine in the current state meets the requirement, executing the step 2.4, otherwise, returning to the step 2.1, and shortening the time of t1 until the starting acceleration of the engine in the current state meets the requirement, and executing the step 2.4;
2.4, calculating a primary starting overshoot relative quantity B1 of the rotating speed of the engine;
step 3: if B1 is less than A1, executing step 4 to perform secondary starting of the engine; otherwise, delay t1, and return to step 2, until under meeting the requirement of the engine starting acceleration, the relative quantity B1 of one-time starting overshoot of the rotational speed of the engine is less than A1;
step 4: secondary start of engine
When the engine is started for the second time, two auxiliary valves 3 are opened at the time t2, and the relative quantity B2 of the secondary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
the method of the secondary starting in the step 4 is the same as the method of the primary starting in the step 2;
step 5: if B2 is less than A2, executing the step 6; otherwise, delay t2, and return to step 4, until the rotational speed of the engine is over-regulated for secondary starting relative quantity B2 < A2 under the condition of meeting the requirement of starting acceleration of the engine;
step 6: t1 and t2 are recorded, and overshoot of the start of the open cycle forced start high altitude rocket engine is reduced.
The control method provided by the invention has been verified through engine starting simulation, a dynamic simulation model is built in the starting process of the open cycle forced starting high-altitude engine to which the control method is applied, the calculation result is shown in figure 3, the maximum value (dimensionless) of the rotational speed of the engine in the relative starting process is reduced from 1.18 to 1.04 after the control method is adopted, namely, the overshoot is reduced from 18% to 4%, the purpose of inhibiting starting overshoot is achieved, and the turbine starting overshoot curve pair before and after the method is implemented, such as shown in figure 4, can be seen from the figure that after the method is adopted, the overshoot is greatly reduced.
The starting simulation calculation result of the engine shows that: the method for reducing the starting overshoot can effectively inhibit the starting overshoot of the open-cycle forced starting high-altitude engine under the condition of not changing the engine structure.
Claims (5)
1. A method for reducing open cycle forced start high altitude rocket engine start overshoot comprising the steps of:
step 1: defining a primary starting overshoot relative quantity threshold value of the rotating speed of the engine as A1, and defining a secondary starting overshoot relative quantity threshold value as A2;
step 2: one-time starting of engine
When the engine is started once, two auxiliary valves (3) are opened at the time t1, and the relative quantity B1 of the primary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
step 3: if B1 is less than A1, executing step 4 to perform secondary starting of the engine; otherwise, delaying t1 and returning to the step 2;
step 4: secondary start of engine
When the engine is started for the second time, two auxiliary valves (3) are opened at the time t2, and the relative quantity B2 of the secondary starting overshoot of the rotating speed of the engine is calculated under the condition that the requirement of starting acceleration of the engine is met;
step 5: if B2 is less than A2, executing the step 6; otherwise, delaying t2 and returning to the step 4;
step 6: t1 and t2 are recorded, so that the open cycle forced start high altitude rocket engine starting overshoot is reduced.
2. A method of reducing open cycle forced start high altitude rocket engine start overshoot according to claim 1, wherein:
the step 2 specifically comprises the following steps:
2.1, when the engine is started once, two auxiliary valves (3) are opened at the time t 1;
2.2, obtaining starting acceleration of the engine in the current state;
2.3, if the starting acceleration of the engine in the current state meets the requirement, executing the step 2.4, otherwise, returning to the step 2.1, and reducing the time of t1 until the starting acceleration of the engine in the current state meets the requirement, and executing the step 2.4;
and 2.4, calculating a primary starting overshoot relative quantity B1 of the rotating speed of the engine.
3. A method of reducing open cycle forced start high altitude rocket engine start overshoot according to claim 2, wherein:
the step 2.1 specifically comprises the following steps:
2.11, before the gunpowder starter (1) of the engine ignites, two component propellants of the engine respectively fill an engine cavity channel in front of a main valve of the engine and an engine cavity channel in front of a secondary valve of the engine, and keep the two secondary valves (3) in a closed state;
starting the gunpowder starter (1) at the moment 2.12 and 0, and rotating the turbine (4) under the pushing of the pressure and flow of the gunpowder gas;
2.13, opening two auxiliary valves (3) at time t1, so that two component propellants enter an engine gas generator (2) to be ignited, gunpowder is combusted to generate fuel gas, and the turbine (4) is driven to move;
2.14, after the gunpowder is burnt out, the gas generator (2) works independently to continuously drive the turbine (4), and the starting process of the engine is finished.
4. A method of reducing open loop forced start high altitude rocket engine start overshoot according to claim 3, wherein:
the step 4 specifically comprises the following steps:
4.1, on the premise that the relative quantity B1 of primary starting overshoot of the rotating speed of the engine is less than A1, when the engine is started for the second time, opening two auxiliary valves (3) at the time t 2;
4.2, obtaining starting acceleration of the engine in the current state;
4.3, if the starting acceleration of the engine in the current state meets the requirement, executing the step 4.4, otherwise, returning to the step 4.1, and reducing the time of t2 until the starting acceleration of the engine in the current state meets the requirement, and executing the step 4.4;
and 4.4, calculating the relative quantity B2 of the secondary starting overshoot of the rotating speed of the engine.
5. A method of reducing open loop forced start high altitude rocket engine start overshoot according to claim 4, wherein:
the method of starting the engine twice in the step 4.1 is the same as that of starting the engine once in the step 2.1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311173046.9A CN117052566A (en) | 2023-09-12 | 2023-09-12 | Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311173046.9A CN117052566A (en) | 2023-09-12 | 2023-09-12 | Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117052566A true CN117052566A (en) | 2023-11-14 |
Family
ID=88662742
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311173046.9A Pending CN117052566A (en) | 2023-09-12 | 2023-09-12 | Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117052566A (en) |
-
2023
- 2023-09-12 CN CN202311173046.9A patent/CN117052566A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111502864B (en) | Open-cycle liquid oxygen kerosene engine system and use method thereof | |
| CN111502865B (en) | Test run method of open-cycle liquid oxygen kerosene engine system | |
| US8893467B2 (en) | Direct injection of a discrete quantity of fuel into channels of a wave rotor engine | |
| CN114060170B (en) | Open staged combustion air-extracting circulation liquid rocket engine | |
| CN109736953B (en) | Multi-start liquid oxygen kerosene engine of gas-driven pre-compressed turbine and starting method | |
| CN111622864B (en) | Semi-open type oxygen-enriched afterburning cycle engine | |
| CN111963340B (en) | Multi-starting system of pneumatic supercharging device of liquid rocket engine | |
| CN211343158U (en) | Gas cylinder multi-start system for pumping pressure type liquid rocket engine | |
| Biggs | Space shuttle main engine the first ten years | |
| CN113958425B (en) | Open-cycle liquid oxygen kerosene engine system and using method thereof | |
| CN117052566A (en) | Method for reducing starting overshoot of open cycle forced starting high altitude rocket engine | |
| JP5939836B2 (en) | Sub-chamber engine and operation control method thereof | |
| CN115288884A (en) | Self-ignition propellant oxygen-enriched afterburning cycle self-starting engine system and method | |
| US20040206089A1 (en) | Integral pulse detonation system for a gas turbine engine | |
| CN116481784A (en) | Parallel type combined power and combined spray pipe verification method | |
| US20200271047A1 (en) | Rotating internal combustion engine | |
| CN112360647A (en) | Multiple starting system of liquid rocket engine and starting control method thereof | |
| CN112901372A (en) | Novel liquid rocket engine | |
| CN116480488A (en) | Self-adaptive starting afterburning cycle engine system and starting method thereof | |
| CN217582323U (en) | Torch igniter for multiple starting of liquid rocket engine | |
| US20180355816A1 (en) | Dual-fuel internal combustion engine | |
| RU2798129C1 (en) | Method for protecting gas turbine engine from surge | |
| CN116044610B (en) | Double-expansion circulation liquid rocket engine system | |
| CN114291296B (en) | Rocket orbit-changing engine power consumption reducing device | |
| CN112901373A (en) | Novel liquid rocket engine multi-machine system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |