A fixed-wing fire-fighting aircraft water dropping effect evaluation method

Abstract

The application provides a fixed-wing fire-fighting aircraft water-throwing effect evaluation method, which comprises the following steps: S1, defining a typical forest fire-fighting task scene based on the distribution of key forest fire-fighting areas in China and surrounding available airports and water sources of fixed-wing aircraft; S2, planning initial refueling amount and single water pumping amount of the fixed-wing aircraft according to flight weight characteristics and performance requirements; S3, calculating fuel consumption, water-throwing frequency, water-throwing amount and operation time of the aircraft in single flight under various typical fire-fighting modes and task scenes according to the typical forest fire-fighting task scene, the initial refueling amount and the single water pumping amount of the fixed-wing aircraft; S4, analyzing the efficiency indexes of the water-throwing amount per hour of the aircraft, the total water-throwing amount per single refueling, the total water-throwing frequency and the task time; and S5, performing comprehensive efficiency evaluation based on an ADC model. The method can comprehensively and accurately evaluate the water-throwing effect of the fixed-wing fire-fighting aircraft based on the distribution of key forest fire-fighting areas in China and surrounding available airports and water sources of fixed-wing aircraft.

Description

Technical Field

[0001] This invention belongs to the field of aerial forest fire prevention and control, and relates to a method for evaluating the water drop effect of fixed-wing firefighting aircraft, including indicators such as forest fire scene, mission planning, water drop volume calculation, flame suppression, and coverage rate. Background Technology

[0002] The applicant's research revealed that forest fires are characterized by rapid spread, long ignition time, high difficulty in extinguishing, and strong destructive power. Current methods primarily include suffocation, cooling, and isolating combustible materials. Cooling methods mainly involve covering with damp soil and water spraying.

[0003] In water-spraying methods, the effectiveness of water droplets from firefighting aircraft is a key indicator of their performance. However, this indicator is influenced by numerous factors, and a comprehensive and systematic evaluation requires a large amount of data on aircraft water droplet characteristics, fire intensity, fuel characteristics, etc. Forest fires are characterized by their suddenness, making it difficult to collect this data in actual fire scenes. Therefore, currently, the effectiveness of aircraft water droplets is mainly judged roughly based on human experience, and a systematic evaluation method and indicator system for aircraft firefighting efficiency has not yet been established. Summary of the Invention

[0004] The purpose of this invention is:

[0005] A comprehensive evaluation model for the firefighting capabilities of fixed-wing aircraft was developed, and a method for demonstration, verification, and evaluation was defined.

[0006] The technical solution of this invention is:

[0007] A method for evaluating the effectiveness of water-dropping from fixed-wing firefighting aircraft is proposed. This method studies the distribution of available water sources and airports for fixed-wing aircraft in forest areas and for firefighting using water droplets in my country, and establishes typical mission scenarios for water-dropping firefighting using fixed-wing aircraft. Based on these typical mission scenarios, a reasonable profile of typical firefighting missions for aircraft is planned. Flight performance analysis is conducted based on the aircraft's water-dropping characteristics, calculating indicators such as the number of water drops, the amount of water dropped, mission time, and fuel consumption. Based on the performance calculation results, the method analyzes the efficiency indicators of fixed-wing aircraft water-dropping firefighting, including hourly water drop volume, total water drop volume per refueling, total number of water drops, and mission time.

[0008] The forest areas mentioned mainly include high-risk fire zones and high-risk fire areas, and are mainly distributed in the forest areas of Northeast and Southwest my country.

[0009] Flight tests were used to study the characteristics of water drop volume (rate of water line construction), distribution direction (difference between the location of water drop and the target), coverage level (coverage of the main combustion points), and impact on the fire (reduction of fire intensity, reduction of fire spread, and duration of fire suppression).

[0010] This invention describes a method for evaluating the effectiveness of water droplets from a fixed-wing firefighting aircraft, specifically including the following steps:

[0011] 1) Define typical forest fire fighting mission scenarios. Define the typical characteristics and relative positions of aircraft performing forest fire fighting missions, such as fire sites, airports, and water sources. Define different fire fighting methods, water drop strategies, and water drop modes to establish typical mission scenarios for fixed-wing aircraft water drop fire fighting.

[0012] 2) Plan typical tasks. Based on the analysis results in 1), rationally plan the initial refueling amount and single water scoop amount of the fixed-wing aircraft according to the flight weight characteristics and performance requirements.

[0013] 3) Flight performance calculation. Based on the results of 1) and 2), calculate the mission performance indicators such as fuel consumption, number of water drops, water volume, and flight time of the aircraft per flight under various typical firefighting modes and mission scenarios.

[0014] 4) Analyze the overall effect of water drop by fixed-wing aircraft. Based on the calculation results in 3), analyze the performance indicators such as the hourly water drop volume for firefighting, the total water drop volume per refueling, the total number of water drops, and the mission time.

[0015] 5) Comprehensive Performance Evaluation. Based on the ADC model, a basic model for comprehensive fire extinguishing performance is constructed:

[0016] E = A * D * C

[0017] A—Effectiveness

[0018] A = Attendance Reliability

[0019] D—Task completion rate.

[0020] D = Hit rate when diving

[0021] C—Water discharge capacity

[0022] Water release capacity model:

[0023] C = (G 单 *n) / t 总

[0024] A higher E value is preferable.

[0025] n—Total number of water-throwings

[0026] n = (a / w) * (b / L) = n1 + n2 + ...

[0027] b. Length of the isolation strip

[0028] L—Effect water hose length for a single water injection

[0029] L = Length of water coverage with a thickness of 1.7mm or more

[0030] Width of the isolation belt

[0031] W - Effective water belt width for a single water injection

[0032] W = Width where the water volume coverage thickness reaches 1.7 mm or more

[0033] n1 - Number of water injections for a single mission

[0034] n1 = (F0 - F1 - F2 - F 备 ) / F 单

[0035] n2 - Number of water injections for the second deployment

[0036] n2 = (a / w) * (b / L) - n1

[0037] n2 - Number of water injections for the second deployment

[0038] t 总 - Total water injection time

[0039] t 总 = t 首 + t1 + t2 + t 单 * n1 + t0 + t1 + t2 + t 单 * n2 +......

[0040] If n2 is 0, then t0 + t1 + t2 + t does not need to be considered 单 * n2

[0041] t_first - Preparation time for the first deployment;

[0042] t1 - Flight time from the airport to the water source

[0043] t2 - Flight time from the fire site to the base

[0044] t 单 - Time for the round trip between the water source and the fire site;

[0045] t0 - Preparation time for the second deployment;

[0046] G 单 - Single water injection volume

[0047] F0 - Fuel consumption required for the initial fuel load mission

[0048] F1 - Fuel consumption from the base to the water source

[0049] F2 - Fuel consumption for the return from the fire site to the base

[0050] F 单 - Fuel consumption for a single round trip between the water source and the fire site

[0051] 6) Based on the fire extinguishing effect of a single aircraft and referring to the characteristics of fire distribution, area, and frequency in the Northeast and Southwest forest areas, suggestions are made for the configuration of fixed-wing aircraft.

[0052] The beneficial effects of this invention are:

[0053] The present invention provides a method for evaluating the water-dropping effect of fixed-wing firefighting aircraft. By studying typical forest firefighting mission scenarios of fixed-wing aircraft, rationally planning firefighting missions, calculating the amount of water dropped by the aircraft, and formulating a comprehensive capability evaluation model, the method assesses the water-dropping firefighting effect of fixed-wing aircraft.

[0054] Based on the distribution of available airports and water sources for fixed-wing aircraft in key forest fire prevention areas and surrounding regions in my country, this evaluation and comparison method avoids being unsuitable for my country's national conditions. The definition of typical aircraft mission profiles and mission planning involved in this evaluation method can provide important functional and performance references for the aircraft design process. It can provide a preliminary comprehensive assessment of the water-dropping effectiveness of fixed-wing firefighting aircraft and offer a reference for equipment procurement and configuration. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, 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.

[0056] Figure 1 A simplified model for fire spread;

[0057] Figure 2 Model of a fire-retardant zone for fire spread;

[0058] Figure 3 A typical water-fighting firefighting mission profile;

[0059] Figure 4 Typical task profile of water injection fire extinguishing;

[0060] Figure 5 A system of indicators for the effectiveness of fixed-wing aircraft in firefighting and water delivery. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] This invention relates to a method for evaluating the effectiveness of water-dropping from a fixed-wing firefighting aircraft. This method is used for a comprehensive evaluation of forest fire suppression by a large amphibious aircraft in a southwestern forest region. The implementation process is as follows:

[0064] 1) Based on historical statistics of forest fires in my country and with reference to the key forest fire prevention areas designated by the State Forestry Administration, which mainly include high-level forest fire areas and high-risk forest fire areas, typical forest fire areas were selected, and environmental conditions such as fire altitude, typical temperature and wind force were defined. The typical fire altitude is 3500m and the typical temperature is ISA+10℃.

[0065] Analysis of forest fire area data shows that, assuming the initial fire area was 1 hectare... 2 (To simplify the fire scene model, it is defined as a regular 100m × 100m model.) Successfully suppressing the fire within 5 hours is considered a success; at this point, the fire will have developed into a 5hm² fire. 2 Based on the fire spread model, it is calculated that, given the wind speed and direction, the fire will develop into a regular 250m × 200m pattern within 5 hours. A simplified model is shown below. Figure 1 As shown.

[0066] 2) Based on the water-drawing characteristics of fixed-wing firefighting aircraft and the water-drawing area requirements, and according to the distribution of surrounding obstacles and altitude, define potential usable water sources for aircraft. The altitude of the water source should not exceed 3,000 meters, including 34 usable water sources such as Qionghai Lake and Lugu Lake, with a typical altitude of 2,000 meters.

[0067] 3) Select airports for fixed-wing aircraft operation based on the characteristics of aircraft take-off and landing on land and water. The airport altitude should not exceed 3,000 meters, including 22 airports such as Xichang Qingshan Airport and Dali Airport. The typical airport altitude is 1,700 meters.

[0068] 4) Selecting a water-fighting strategy. Water-fighting can be divided into direct and indirect methods. Direct water-fighting includes water-drawing and water-injection modes. For fires with large areas, strong winds, and complex terrain, indirect methods such as firebreaks are preferred, as in the Muli fire. For fires in their initial stages, with small areas and flat terrain, direct water-fighting is preferred, as in the Xichang fire.

[0069] Considering 5hm 2The fire area is too large, and direct firefighting is not feasible under current conditions. Therefore, a fire-blocking method using water to create a firebreak will be employed. Based on the aforementioned fire spread model, it is proposed to deploy a 250m long water hose within 5 hours to achieve a flame-retardant effect. The model for adding a flame-retardant hose is as follows: Figure 2 As shown. The water adhesion time is not considered here, and no superimposed water injection assessment is performed.

[0070] 5) Based on the relative locations and altitudes of the fire site, airport, and water source as defined above, establish typical mission scenarios for fixed-wing aircraft to extinguish fires by drawing water, following the principle of proximity. (Reference) Figure 3 Typical mission scenarios include takeoff, climb, cruise, descent, water intake, water drop, return, and landing, and define relatively typical distances and environmental conditions for airports, water sources, and fire sites; the distance between the airport and the water source in the Southwest Forest Area is 120km, the distance between the water source and the fire site is 50km, and the distance between the fire site and the airport is 120km.

[0071] 6) Select the water injection mode. For strong fires, use the rapid water injection mode (12t water per injection). For weak fires, use the maximum water injection mode (increasing from 9t to 12t as fuel is consumed). (Reference) Figure 4 Typical mission scenarios include takeoff, climb, cruise, descent, water drop, climb, cruise, descent, and landing.

[0072] 7) Based on the flight weight characteristics and performance requirements, the initial refueling amount and water intake amount for fixed-wing aircraft should be planned reasonably. The initial water intake amount for the Xichang fire was 9t, and the water intake amount increased from 9t to 12t as fuel consumption increased.

[0073] 8) Calculate the mission performance indicators such as fuel consumption, number of water drops, water volume, and flight time for a single flight of the aircraft under various typical fire extinguishing modes and mission scenarios.

[0074] 9) Based on the above performance evaluation model,

[0075] The values ​​of various indicators for water-based fire extinguishing were calculated. Based on the data of water drop from the large amphibious aircraft 001, the effective water spraying area with a coverage thickness of 1.7mm / L is approximately 87m*30m, with an average thickness of 2.7mm.

[0076] ESouthwest = A * D * C = 16.6

[0077] 10) Based on the firefighting effectiveness of a single aircraft and considering the characteristics of fire distribution, area, and frequency in the Southwest forest region, recommendations for fixed-wing aircraft configuration are proposed. Given the characteristics of small fire areas and high fire frequency in the Southwest forest region, it is recommended to deploy 4-5 large amphibious firefighting aircraft at each of the following airports: Mianyang Nanjiao Airport, Xichang Qingshan Airport, Dali Airport, and Pu'er Simao Airport.

[0078] refer to Figure 5The firefighting and water-dropping effectiveness index system for large amphibious fixed-wing aircraft includes: coordination capability, environmental conditions, flight characteristics, water-dropping system characteristics, mission capability, reliability, availability, and cost.

[0079] It should be noted that the above process operations can be combined to varying degrees. For the sake of brevity, the implementation methods of various combinations will not be elaborated here. Those skilled in the art can flexibly adjust the order of the above operation steps or flexibly combine the above steps according to actual needs.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A method for evaluating the water-dropping effect of a fixed-wing firefighting aircraft, characterized in that, It includes the following steps: S1 defines typical forest fire fighting scenarios based on the distribution of available airports and water sources for fixed-wing aircraft in key forest fire prevention areas and surrounding areas of my country. S2, based on typical forest fire fighting mission scenarios, and considering flight weight characteristics and performance requirements, plans the initial refueling amount and single water scooping amount for fixed-wing aircraft; S3, based on typical forest fire fighting mission scenarios, initial refueling amount of fixed-wing aircraft and single water scooping amount, calculate the mission performance indicators of fuel consumption, number of water drops, water drop volume and running time of aircraft per flight under various typical fire fighting modes and mission scenarios. S4 analyzes the performance indicators of aircraft firefighting hourly water volume, total water volume per refueling, total number of water drops, and mission time. S5, based on the ADC model, performs a comprehensive performance evaluation; Based on the firefighting effectiveness of a single aircraft and taking into account the fire distribution, area, and frequency characteristics of forest fires in Northeast and Southwest China, S6 proposes recommendations for the configuration of fixed-wing aircraft. Step S5 includes: Based on the ADC model, a basic model for comprehensive fire extinguishing effectiveness is constructed: E = A * D * C; A represents attendance reliability; D represents the water-throwing hit rate; C represents the water delivery capacity model; C=(G 单 *n) / t 总 n represents the total number of times water was thrown in; n=(a / w)*(b / L)= n1+n2; b is the length of the isolation strip; L is the effective water hose length for a single water injection; A represents the width of the isolation strip; W represents the effective width of the water jet in a single water injection; n1 represents the number of water drops in a single task; n1 = (F0-F1-F2-F 单 ) / F 单 ; n2 represents the number of times the water can be deployed again. n2 = (a / w) * (b / L) - n1; t 总 This refers to the total water injection time; t 总 =t 首 + t1+ t2+ t 单 *n1+ t0+ t1+ t2+ t 单 * n2; If n2 is 0, then t0 + t1 + t2 + t does not need to be considered. 单 * n2; The first step is the preparation time for the initial deployment; t1 is the flight time from the airport to the water source; t2 is the flight time from the fire site to the base; t 单 The time spent traveling between the water source and the fire site; t0 is the preparation time for another deployment; G 单 This refers to the amount of water added in a single operation. F0 represents the initial fuel load and the amount of fuel required for the mission. F1 represents fuel consumption from the base to the water source. F2 represents the fuel consumption for returning to base from the fire. F 单 This refers to the fuel consumption for a single round trip between the water source and the fire site.

2. The method according to claim 1, characterized in that, Step S1 includes: Define the typical characteristics and relative positions of fire sites, airports, and water-source aircraft in forest fire fighting missions; define different fire fighting methods, water drop strategies, and water drop modes; and establish typical mission scenarios for fixed-wing aircraft water-dropping fire fighting.

3. The method according to claim 1, characterized in that, in: Typical forest fire fighting scenarios are based on fire fighting scenarios in the forest areas of Northeast and Southwest my country.

4. The method according to claim 1, characterized in that, The typical fire extinguishing modes include: For fire sites with large areas, strong winds, and complex terrain, choose the indirect fire extinguishing mode with firebreaks. For fires that are in their initial stages, small in area, and on flat terrain, the direct water injection method should be selected.

5. The method according to claim 1, characterized in that, in: Fixed-wing firefighting aircraft are large amphibious aircraft.

6. The method according to any one of claims 1-5, characterized in that, in: Typical mission scenarios include: takeoff, climb, cruise, descent, water scooping, water drop, return, and landing of fixed-wing firefighting aircraft.

Images