Airport low-altitude wind shear forecasting and early warning method based on computational fluid mechanics

Abstract

The invention discloses an airport low-altitude wind shear forecasting and early warning method based on computational fluid mechanics. The airport low-altitude wind shear forecasting and early warning method is used for forecasting and early warning of low-altitude wind shear or low-altitude turbulence formed by interaction of strong wind and terrain. The method comprises the following steps of S1, performing physical modeling on an airport and a terrain environment within a certain range around the airport by importing real terrain data; s2, analyzing weather examples of historical strong wind with wind shear weather of the target airport, and determining wind direction and wind speed parameters of a boundary layer in strong wind weather; and S3, based on computational fluid mechanics, generating vortex distribution diagrams on a glide path (five sides of the airport) and a take-off and climbing path (one side of the airport) of the aircraft by using fluid simulation software and wind speed parameters, and representing wind shear and turbulence distribution areas. And S4, changing wind speed parameters, repeating the step S3, outputting vortex distribution conditions under different wind direction and wind speed conditions, and establishing a picture library. And S5, combining the picture library generated in the step S4 with a numerical forecasting mode and a radar product for application.

Description

Technical Field

[0001] The invention belongs to the field of aviation meteorological forecasting, and relates to the forecasting and early warning technology of low-altitude wind shear and low-altitude turbulence in aviation operations. Background Art

[0002] Wind shear refers to the vector difference of wind between two points in space. Wind shear is divided into horizontal wind shear and vertical wind shear. In aviation meteorology, low-altitude wind shear usually refers to vertical wind shear below 600m above the ground. Low-altitude wind shear seriously endangers the safety of aviation activities, especially during the takeoff and landing phases of aircraft. Low-altitude wind shear will be affected by multi-scale weather systems, with small temporal and spatial scales, high intensity, sudden occurrence and disappearance, etc. Low-altitude wind shear is difficult to detect and predict, which will bring a series of difficulties to air traffic control and flight. With the continuous increase in air transport volume, the harm of wind shear will become more and more serious.

[0003] In aviation meteorology, low-level wind shear can usually be divided into cold front type, jet stream type, thunderstorm type and inversion type according to the type of occurrence. In addition, under the interaction of strong wind and terrain, eddy currents will also form on the leeward side of the mountain, causing low-level turbulence or low-level wind shear. This type of wind shear often occurs at Dalian Zhoushuizi International Airport. Dalian Airport is located in the hilly area of ​​Liaodong Peninsula. From late autumn to early spring, whenever the Mongolian high pressure moves eastward and southward, Dalian Airport is in front of the high pressure, and northerly strong winds often occur. The low-level wind shear or low-level turbulence caused by the northerly strong wind and terrain is the most important low-level wind shear that affects the flight safety of Dalian Airport. Commonly used detection methods for this type of wind shear or turbulence include laser wind radar, wind profiler radar and low-level wind shear warning system. Their detection and calculation principles are mainly based on the definition of wind shear, and there are very obvious detection deficiencies: single-point measurement of wind profiler radar is insufficient for plane or track detection, laser wind radar has the disadvantage of being unable to measure cross-wind and calculate cross-wind shear, and the numerical forecast model filters out turbulent eddies after parameterization of the boundary layer and cannot calculate the wind shear or eddy caused by the interaction between strong wind and terrain; in addition, various detection products and models cannot be effectively networked and perform data assimilation, which reduces the forecast and warning efficiency of wind shear. Summary of the invention

[0004] A method for forecasting and warning low-altitude wind shear at an airport based on computational fluid dynamics, characterized in that in the process of solving the low-altitude wind shear or turbulence caused by the interaction between strong winds and terrain, after using the wind field data predicted by the numerical model or the wind field data detected by radar as input data, fluid simulation is performed according to computational fluid dynamics, and the vortex distribution produced by the simulation is used to represent the area where low-altitude wind shear or low-altitude turbulence occurs.

[0005] The technical solution of the present invention is as follows: S1. First, according to the actual geographical location of the airport, import the real terrain data, and conduct physical modeling of the terrain environment of the airport and a certain range around it, focusing on the mountains and track direction in the upwind area, with a grid scale of 30m x 30m; S2. Analyze the historical weather cases of strong winds accompanied by wind shear at the target airport, and determine the height of the top of the boundary layer friction layer and the wind direction and speed range of the top of the friction layer during strong wind weather; S3. Based on computational fluid dynamics, using fluid simulation software, set a constant wind direction and wind speed uniformly at the top of the friction layer, set a certain wind direction and wind speed at a height of 10 meters, and according to the formula u = U 10 ( z / 10) α generate α After the numerical value is calculated, the location of the vortex area under the action of strong wind and terrain is simulated; the vortex distribution map on the aircraft glide path (five sides of the airport) and the takeoff climb path (one side of the airport) is generated, including the vertical section vortex distribution map perpendicular to the runway direction and the section vortex distribution map passing the glide path and perpendicular to the previous vertical section; the vortex distribution position is used to represent the location of low-altitude wind shear and low-altitude turbulence.

[0006] S4. Change the wind direction and wind speed values ​​at the friction layer height, repeat S3, output the vortex distribution on the fifth side and one side of the airport under different wind direction and wind speed conditions, and establish a picture library; S5. Apply the image library generated by S4; manually retrieve the impact of vortices on take-off and landing aircraft under different wind directions and speeds according to the estimated wind direction and speed; update and display the impact position of vortices on take-off and landing aircraft in real time according to the fixed-altitude wind field data updated in real time by the laser wind radar or wind shear radar; display the impact position of vortices on take-off and landing aircraft in real time according to the forecast results of numerical forecast products for fixed-altitude wind field data. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic flow chart of the method of the present invention.

[0008] Figure 2 This is a schematic diagram of the modeling range of Dalian Airport and its surroundings in an embodiment of the present invention. Figure 3 This is a schematic diagram of modeling of Dalian Airport and its surroundings in an embodiment of the present invention Figure 4 The wind distribution diagram with height in two typical wind shear weather cases in the embodiment of the present invention is Figure 5 Schematic diagram of vorticity field simulation results (including topographic map) in an embodiment of the present invention Figure 6Schematic diagram of vorticity field simulation results in an embodiment of the present invention (excluding topographic map) Figure 7 Schematic diagram of vorticity field simulation results in an embodiment of the present invention (including the glide path and climb path) DETAILED DESCRIPTION

[0009] Taking Dalian Zhoushuizi International Airport (Dalian Airport for short) as an example, Dalian Zhoushuizi International Airport will experience low-level wind shear and low-level turbulence under strong northerly wind conditions. Dalian is surrounded by the sea on three sides and its land is hilly. Dalian Airport is surrounded by mountains on three sides, and there are 200-300-meter high mountains in the north and south of the airport. When the northerly wind prevails in Dalian, affected by the terrain around the airport, low-level turbulence or wind shear weather often forms near the ground layer of the airport. For example, from January 13 to 15, 2023, affected by the eastward and southward movement of the Mongolian high pressure, Dalian Airport experienced strong northerly winds. During the strong winds, Dalian Airport experienced a long period of low-altitude wind shear, and the wind shear caused more than 70 flights to go around; on March 15, 2018, affected by the eastward and southward movement of the Mongolian high pressure, Dalian Airport experienced strong northerly winds. During the strong winds, Dalian Airport experienced a long period of low-altitude wind shear, and the forecast room received 8 voice aircraft reports, affecting a total of 14 flights, causing 16 go-arounds, of which 2 flights went around twice.

[0010] The terrain modeling was carried out in Dalian Airport and its surrounding areas. The direction of the airport runway is east-west. The mountainous area to the north of the airport and its glide path is the focus area of ​​terrain modeling. A rectangular area of ​​10km by 20km was selected as the modeling area, focusing on the runway and its glide path and the mountainous area to the north of it ( Figure 2 , Figure 3 ).

[0011] The distribution of high and low altitude wind fields when wind shear occurs in Dalian is analyzed. It is found that the top of the friction layer in typical wind shear weather is about 500m, the wind speed varies between 15-25m / s, the average wind speed at a height of 10m near the ground is between 7-13m / s, and the wind direction is mostly northerly (360°) ( Figure 4 ); The wind direction at 500m is initially set to 360° and the wind speed is 20m / s; The wind direction at 10m is initially set to 360° and the wind speed is 10m / s. According to the formula u = U 10 ( z / 10) α The calculation results show that α=0.1772.

[0012] According to the above parameters, the flow field distribution in the selected area is simulated using ANSYS fluid simulation software, the vorticity (Vorticity Magnitude) value is output, and a vertical profile is displayed along the runway direction ( Figure 5 , Figure 6 ), according to the output results, areas with vorticity values ​​greater than 0.05 can be considered to have wind shear or turbulence.

[0013] Repeat the setting of wind direction and wind speed at a height of 500m and 10m, output the graphic library as the display library for forecast and warning products, and make data labels.

[0014] It can be further combined with laser wind radar, wind profile radar or model output values ​​to achieve automatic update display.

[0015] Beneficial effects of the present invention: Based on the estimated wind direction and speed, the impact of vortices on take-off and landing aircraft under different wind directions and speeds can be manually retrieved; The position of the vortex affecting the take-off and landing aircraft can be updated in real time based on the wind field data of fixed altitude layers updated in real time by the laser wind radar or wind shear radar; Based on the forecast results of numerical forecast products for wind field data at fixed altitude layers, the impact position of vortices on take-off and landing aircraft can be displayed in real time.

[0016] The present invention makes up for the shortcoming of insufficient plane or track detection of single-point measurement of wind profile wind measuring radar, the shortcoming of inability to measure lateral wind and calculate lateral wind shear of laser wind measuring radar, and the shortcoming of inability to calculate wind shear or eddy caused by interaction between strong wind and terrain after filtering turbulent eddy currents in numerical forecast models after parameterization of boundary layer.

[0017] The present invention also provides a feasible solution for the detection of low-altitude wind shear and low-altitude turbulence by data networking such as laser radar, wind measuring radar and numerical model.

Claims

1. A method for forecasting and warning low-altitude wind shear at an airport based on computational fluid dynamics, characterized in that In the process of solving the low-level wind shear or turbulence caused by the interaction between strong winds and terrain, after using the wind field data predicted by the numerical model or the wind field data detected by radar as input data, fluid simulation is performed according to computational fluid dynamics, and the vortex distribution produced by the simulation is used to represent the area where low-level wind shear or low-level turbulence occurs.

2. The method for forecasting and warning low-altitude wind shear at an airport based on computational fluid dynamics according to claim 1 is characterized in that: The processing steps are as follows: S1. Import real terrain data and conduct physical modeling of the terrain environment of the airport and a certain range of its surroundings, with a grid scale of 30m x 30m; S2. Analyze the historical weather cases of strong winds accompanied by wind shear at the target airport, and determine the height of the top of the boundary layer friction layer and the wind direction and speed range of the top of the friction layer during strong wind weather; S3. Based on computational fluid dynamics, using fluid simulation software, set a certain wind direction and wind speed to appear uniformly at the top height of the friction layer, set a certain wind direction and wind speed at a height of 10 meters, generate the α value according to the formula u=U10(z / 10)α, and simulate the location of the vortex area under the action of strong wind and terrain; generate the vortex distribution map on the aircraft glide path (the fifth side of the airport) and the take-off climb path (one side of the airport), including the vertical section vortex distribution map perpendicular to the runway direction and the section vortex distribution map passing the glide path and perpendicular to the previous vertical section; use the vortex distribution position to represent the location of low-altitude wind shear and low-altitude turbulence; S4. Change the wind direction and wind speed values ​​at the friction layer height, repeat S3, output the vortex distribution on the fifth side and one side of the airport under different wind direction and wind speed conditions, and establish a picture library; S5. Apply the image library generated by S4; manually retrieve the impact of vortices on take-off and landing aircraft under different wind directions and speeds according to the estimated wind direction and speed; update and display the impact position of vortices on take-off and landing aircraft in real time according to the fixed-altitude wind field data updated in real time by the laser wind radar or wind shear radar; display the impact position of vortices on take-off and landing aircraft in real time according to the forecast results of numerical forecast products for fixed-altitude wind field data.

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