A thermal climate flight test method for a fuel system of a tropospheric manned airship

Abstract

The present application belongs to the technical field of flight test, and particularly relates to a kind of troposphere manned airship fuel system hot climate test flight method. Including: S1: determining test flight condition;S2: make airship climb to the minimum safe height after stable flight first time, gradually increase the power of transmitter to maximum continuous power;S3: after speed stabilization, climb to maximum use height at maximum continuous power;S4: monitor fuel pressure, fuel flow and engine operation during climbing, monitor whether there is gas lock phenomenon caused by fuel overheating, which leads to unstable engine operation;S5: if there is no gas lock phenomenon caused by fuel overheating, which leads to unstable engine operation, airship climbs to maximum use height, returns and lands;S6: if fuel pressure is within normal range, fuel flow is within normal range, and engine does not work abnormally due to fuel interruption during test, then fuel system hot climate test flight is completed.

Description

Technical Field

[0001] This invention belongs to the field of flight test technology, specifically relating to a thermal climate test method for the fuel system of a tropospheric manned airship. Background Technology

[0002] Currently, China lacks flight test technologies and methods for the qualification certification of tropospheric airships. There is a need to implement repeatable and standardized flight test requirements for airships, standardizing flight test preparation, procedures, and methods to form unified verification requirements and improve the efficiency and quality of manned airship flight tests. Summary of the Invention

[0003] Purpose of the invention: To provide a hot climate flight test method for the fuel system of a tropospheric manned airship, filling the gap in the hot climate flight test method for the fuel system of a tropospheric manned airship, and improving the flight test efficiency and quality of manned airships.

[0004] Technical solution: A hot climate test method for the fuel system of a tropospheric manned airship includes: S1: Determine the conditions for test flight; S2: After the airship climbs to the minimum safe altitude and stabilizes in level flight, gradually increase the transmitter power to the maximum continuous power. S3: After the speed stabilizes, climb to the maximum operating height with maximum continuous power; S4: During the climb, monitor fuel pressure, fuel flow and engine operation, and monitor for the presence of vapor lock caused by fuel overheating, which could lead to unstable engine operation. S5: In the absence of fuel overheating causing airlock and resulting engine instability, the airship climbs to its maximum operating altitude and returns to land. S6: If the fuel pressure and fuel flow are within the normal range, and the engine does not malfunction due to fuel interruption during the test, then the hot climate test of the fuel system is complete.

[0005] Furthermore, in S1, the test flight conditions include: The boat is equipped with an auxiliary fuel supply system, a fuel pressure sensor, and a fuel temperature sensor. Determine the initial fuel level in the fuel tanks and fill the main engine fuel tank to its initial level, then fill all other fuel tanks to the maximum. Determine the ambient temperature and fuel temperature.

[0006] Furthermore, the initial fuel level in the fuel tank = the fuel level required for the test + the amount of unavailable fuel.

[0007] Furthermore, ambient temperature: ≥85°F.

[0008] Furthermore, the initial fuel temperature is 44–46°C.

[0009] Furthermore, in S2, the first time is 1 minute.

[0010] Furthermore, in S3, the climb rate must maintain the airbag pressure within the normal range.

[0011] Furthermore, in S2, the minimum safe height is 50m to 100m above the field height.

[0012] Furthermore, in S3, the rate of ascent is no greater than 7 m / s.

[0013] Beneficial effects: This invention fills a gap in the test flight method for the thermal climate type qualification certification of tropospheric manned airships' fuel systems, realizing a repeatable and standardized test flight plan. It standardizes test flight preparation, test flight procedures, and test flight methods, forming unified verification requirements and improving the test flight efficiency and quality of tropospheric manned airship fuel systems in thermal climate conditions. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of a thermal climate test flight method for the fuel system of a tropospheric manned airship according to the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0018] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0020] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0022] The Civil Aviation Administration of China (CAAC) issued the type certification for the airship (AC-21-AA-2009-09R1), which adopted FAA P-8110-2 airship design guidelines, specifically Clause 5.14 regarding the thermal climate requirements of the fuel system. It explicitly requires that fuel be used under critical operating conditions at an air temperature of 110°F (43°C), under which time each fuel system must be free from vapor lock. Based on these requirements, this invention clarifies the flight test method for the thermal climate conditions of the airship fuel system and provides qualification criteria.

[0023] A hot climate flight test method for the tropospheric manned fuel system applicable to FAA P-8110-2, comprising the following steps: Step 1: Preparing conditions for flight testing; 1) Weight and center of gravity: No requirement; 2) Airship is equipped with: auxiliary fuel supply system, fuel pressure sensor, and fuel temperature sensor; the onboard fuel system supplies fuel to one main engine, and the auxiliary fuel tank supplies fuel to the other engines; 3) Fuel quantity: Initial fuel quantity in the fuel tank = fuel quantity required for the test + unusable fuel quantity; fill the auxiliary fuel tank with fuel; 4) Ambient temperature: ≥85°F (29.4℃); 5) Fuel temperature: Hot water heats aviation gasoline to over 46°C, then adds it to the main fuel tank and allows it to stand until it reaches its initial temperature (44-46)°C.

[0024] Step 2: After the airship climbs to the minimum safe altitude, it flies steadily for 1 minute, and then gradually increases the transmitter power to the maximum continuous power. Step 3: After the speed stabilizes, climb to the maximum operating height with maximum continuous power (maximum throttle) (climb rate ≤ the climb rate that keeps the airbag pressure within the normal range). Step 4: During the climb, the pilot monitors fuel pressure, fuel flow and engine operation, and monitors for any vapor lock caused by fuel overheating, which could lead to unstable engine operation.

[0025] Step 5: If not, the airship climbs to its maximum operating altitude and returns to land; Step 6: Criteria for Qualification; 1) Throughout the entire test, the fuel pressure remained within the normal range; 2) Throughout the entire test, the fuel flow rate remained within the normal range; 3) Throughout the entire test, the engine did not malfunction due to fuel interruption (there was no vapor lock caused by fuel overheating, which would have led to unstable engine operation). Step 7: Complete the hot climate test flight of the fuel system.

[0026] The thermal climate implementation process for the fuel system of a tropospheric manned airship is as follows: Figure 1 As shown: The following will provide a detailed explanation with examples: Implementation Example: The thermal climate type qualification test flight process for the fuel system of a manned airship is as follows: 1) Set up the test conditions according to the test requirements before the test; Test conditions: Select the normal weight and normal center of gravity of the airship as the test benchmark, the sea surface ambient temperature is 31.2℃, the auxiliary fuel tank is filled with fuel, use (70±5)℃ hot water to heat the aviation gasoline to (52~55)℃, after filling the fuel tank, let it stand until the initial temperature (44~46)℃, and the displayed fuel quantity is 43L.

[0027] 2) Once the temperature stabilizes at (44~46)℃, start the engine immediately and perform pre-flight checks; 3) After the airship flies normally to the field altitude (50m~100m), the engine continuously climbs at maximum power (maximum throttle) (climb rate not greater than 7m / s) to the maximum operating altitude; 4) Pilots monitor fuel pressure, fuel flow and engine operation, and monitor for fuel overheating that could cause vapor lock, leading to unstable engine operation. 5) After climbing to the maximum operating altitude, return and land normally; 6) Criteria for successful experiment: i) Fuel pressure is in the range of 97 kPa to 310 kPa; ii) Fuel flow rate is in the range of (0~76) L / h; iii) During the test, the engine did not malfunction due to fuel interruption.

[0028] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for hot climate flight testing of the fuel system of a tropospheric manned airship, characterized in that, include: S1: Determine the conditions for test flight; S2: After the airship climbs to the minimum safe altitude and stabilizes in level flight, gradually increase the transmitter power to the maximum continuous power. S3: After the speed stabilizes, climb to the maximum operating height with maximum continuous power; S4: During the climb, monitor fuel pressure, fuel flow and engine operation, and monitor for the presence of vapor lock caused by fuel overheating, which could lead to unstable engine operation. S5: In the absence of fuel overheating causing airlock and resulting engine instability, the airship climbs to its maximum operating altitude and returns to land. S6: If the fuel pressure and fuel flow are within the normal range, and the engine does not malfunction due to fuel interruption during the test, then the hot climate test of the fuel system is complete.

2. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, In S1, the test flight conditions include: The boat is equipped with an auxiliary fuel supply system, a fuel pressure sensor, and a fuel temperature sensor. Determine the initial fuel level in the fuel tanks and fill the main engine fuel tank to its initial level, then fill all other fuel tanks to the maximum. Determine the ambient temperature and fuel temperature.

3. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 2, characterized in that, Initial fuel level in the fuel tank = fuel required for the test + unusable fuel level.

4. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 3, characterized in that, Ambient temperature: ≥85°F.

5. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, Initial fuel temperature: 44–46°C.

6. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, In S2, the first time is 1 minute.

7. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, In S3, the climb rate should be maintained so that the airbag pressure is within the normal range.

8. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, In S2, the minimum safe height is 50m to 100m above the field height.

9. The thermal climate test flight method for the fuel system of a tropospheric manned airship according to claim 1, characterized in that, In S3, the rate of ascent is no greater than 7 m / s.

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