38 results about "Downburst" patented technology

The present invention discloses an airplane attitude control method under the influence of a wind field. The method comprises the following steps of 1, establishing an airplane motion equation under the influence of the wind field; 2, establishing a micro-downburst wind field suitable for the flight real-time simulation based on the vortex ring principle; 3, designing a control loop based on a non-linear dynamic inversion theory; 4, establishing an overall simulation model containing the wind field and the control, and changing a gain coefficient in the model by a tracking result. According to the present invention, the micro-downburst wind field established based on the vortex ring principle can be embedded in a flight real-time simulation model to calculate the wind field at an airplane center of mass position real-timely, thereby improving the calculation precision, and being suitable for the aircraft motion and control simulation under the influence of the wind field.

The invention provides a method for determining a downburst wind profile of a horizontal movement. The method comprises the following steps of 1, simulating a jet model of a downburst; 2, transforming the jet model into a numerical calculation model; and 3, determining the downburst wind profile of the horizontal movement. By the method, a wind speed computation formula of the downburst is put forward based on the simulation result of the full size computational fluid dynamics (CFD), and a theoretical reference is provided for engineering design. The method is simple in form, thorough in consideration factors, high in precision and efficient in computation.

The invention discloses a downburst intelligent identification and early warning method based on radar data. Firstly the optical flow field of the reflectivity factor vertical section is analyzed by using an optical flow method so as to obtain the development law of the storm core along with time; then function fitting is performed on the descending process of the top of the storm core by using the Lagrange mechanical model; and then matching identification is performed on the images of the "positive and negative velocity pairs" of the radial velocity field of the middle layer of the storm core by using the histogram and the Bhattacharyya coefficient statistical analysis method, and downburst intelligent early warning is finally realized through synthesis of judgment of a series of thresholds. With application of the method, the potential downburst can be identified in the early stage of lifting and sharp descending of the storm core and the descending rate of the storm core and the time of reaching the near surface can be estimated so that downburst intelligent identification and early warning can be realized.

The present invention discloses a wind tunnel test device for simulating thunderstorm downbursts. The wind tunnel test device comprises four vertical brackets, two oppositely-arranged vertical flow guiding plates and one or more tilt flow guiding plates; the vertical brackets are fixed in a wind tunnel test section through bolts at the upper ends and lower ends of the vertical brackets; a plurality of bolt limiting holes are evenly formed in each vertical bracket along the height direction of the vertical bracket; two sides of each vertical flow guiding plate are fixed into the bolt limiting holes of the corresponding vertical brackets; the tilt flow guiding plates are located between the two vertical flow guiding plates; the front ends and back ends of the left side edge and right side edge of each tilt flow guiding plate are provided with two sets of guide rails; each set of guide rails is slidingly connected with sliders; the sliders are fixed into the bolt limiting holes of the corresponding vertical brackets; and the tilt angles of the tilt flow guiding plates can be adjusted through moving the sliders upwards and downwards. The wind tunnel test device of the invention has the advantages of simple structure and flexible use. According to the wind tunnel test device, the profiles of the thunderstorm downbursts can be simulated in a conventional boundary layer wind tunnel without special construction of a thunderstorm downburst laboratory required, and therefore, a lot of financial resources and manpower can be saved, and the research area of the conventional boundary layer wind tunnel can be greatly expanded.

The invention discloses an experimental device for simulating dynamic characteristics of a high-voltage transmission conductor under the action of downburst. The experimental device is characterized in that four vertical columns of a rectangular supporting platform are fixed onto the ground, and an axial flow fan is mounted on the rectangular supporting platform. Wind speed is regulated by a frequency converter, and different downburst wind speeds are simulated. The transmission conductor is simulated by the aid of a hollow aluminum tube, and two solid shafts are welded at two ends of the aluminum tube respectively. Two spring-damping systems are suspended at two ends of each solid shaft respectively and fixed to two rectangular frames, and the dynamic characteristics of the hollow aluminum tube at different dip angles, different wind angles and different positions are analyzed by horizontal and vertical relative movement of the rectangular frames. A nozzle and a water supply device are connected with each other and fixed at a 1m position under the axial flow fan, water is sprayed to the hollow aluminum tube to simulate various rainfall states, and the water supply device comprises a water reservoir and a water pump. Rainfall is adjusted by an adjusting valve. A displacement sensor and an acceleration sensor are mounted on the outer sides of the two ends of each solid shaft respectively, and acquired signals are transmitted to an acquisition card through a data line.

The invention discloses a method for simulating downburst by coupling wall surface jet flow and a boundary layer wind tunnel of a multi-blade wing grid, which comprises the steps of starting an axialflow fan of a wall surface jet flow device to obtain a jet flow wind field, adjusting the height of an air outlet of the wall surface jet flow device and the angle of an air outlet adjusting plate soas to change the spatial characteristic distribution of the jet flow wind field, and enabling the maximum radial wind speed of the jet flow wind field to appear at a set height; starting a wind tunnelfan at the same time, and forming a background wind field with the set flow speed in a wind tunnel flow channel; coupling the jet flow wind field and the background wind field, and obtaining a downburst outflow wind field with set spatial characteristic distribution; and adjusting the angle of a guide plate of the guide device to change along with time according to a set rule so as to enable thespatial characteristic distribution of the background wind field to change along with time, enabling the flow field characteristic of the downburst outflow wind field to change along with time, and simulating the abrupt change characteristic of the downburst outflow wind field changing along with time. Space characteristics of downburst outflow air development areas can be simulated, and time-varying unsteady characteristics and vortex area development characteristics of downburst outflow air can also be simulated.

The invention discloses a downburst wake flow section wind field simulation device. The downburst wake flow section wind field simulation device can simulate a downburst wake flow section wind field,and the simulation of the downburst relatively large geometric scale ratio wind field is realized. The downburst wake flow section wind field simulation device comprises a boundary layer wind tunnel,a wall surface jet air duct and a mixed flow fan, wherein a receding opening is formed in the bottom wall of the boundary layer wind tunnel; the wall surface jet air duct is arranged at the receding opening, and the wall surface jet air duct is C-shaped; the mixed flow fan is mounted in the air inlet in the side end of the lower part of the wall surface jet air duct; the air outlet in the upper part side end of the wall surface jet air duct is located in the boundary layer wind tunnel, and the direction of the air outlet is the same as the air outlet direction of the boundary layer wind tunnel; and the device is used for simulating the wind field of the downburst wake flow section.

The invention relates to a multi-fan active controlling tornado wind tunnel which mainly comprises a wind tower, a multi-fan section, a rotary disc, a translational motion mechanism and a lifting mechanism. The multi-fan section comprises an upper single-fan section located in the center of the top layer of the wind tower and multiple lower single-fan sections evenly and circumferentially distributed at the bottom of the wind tower, the rotary disc is located at the bottom of the wind tower, the translational motion mechanism is mounted on the upper surface of the rotary disc, and the liftingmechanism is mounted on the translational motion mechanism. The multi-fan active controlling tornado wind tunnel has the advantages of simple structure, the wind tower is integrally of a barrel structure, and blowing and inhaling functions of all the single-fan sections can be achieved; tornados and downburst wind fields can be simulated, translational motion effect of the tornados can be achievedby adjusting the translation motion mechanism, and depth-width ratio of wind fields of the tornados can be adjusted by adjusting a lifting platform of the lifting mechanism in height.

The invention provides a radar three-dimensional wind field inversion method based on high-resolution mode dynamic constraint, and the method comprises the following steps: determining the inversion resolution and range, and building an analysis grid; acquiring a three-dimensional wind field of the high-resolution numerical forecasting system in the inversion area in the short-term and imminent forecasting time efficiency, and interpolating the three-dimensional wind field to the analysis grid; extracting radial wind elements from the polarization radar in the inversion area, performing speed deblurring processing, and interpolating to an analysis grid; on the basis of establishing a cost function by means of a radial speed, a mass continuity equation and a smooth item, adding a mode dynamic constraint item to form a new cost function; and performing iterative solution based on a cost function minimization principle, and finally obtaining a complete three-dimensional wind field in the region. According to the method, through high-resolution mode dynamic constraint, the three-dimensional wind field obtained through radar inversion has physical and dynamic coordination, the completeness and precision of wind field inversion can be improved, and the monitoring and early warning capacity for strong weather such as vertical wind shear and downburst can be effectively improved.

The invention relates to a method for designing low-altitude wind shear models by means of fusing vortex rings and discrete gust models. The method includes designing micro-downburst models and the discrete gust models. The method includes steps of firstly, establishing the vortex rings in runway coordinate systems; secondly, determining vortex ring centers, vortex ring radiuses and central perpendicular wind speeds to obtain vortex ring models with fixed vortex ring central intensity; thirdly, configuring mirror vortex rings; fourthly, importing the discrete gust models; fifthly, adjusting gust gradients of the gust models imported at the fourth step; sixthly, adjusting the relative locations of the centers of the gust models and the centers of the vortex rings so that the magnitude of wind shear central intensity can be changed at any moment, and the magnitude of the intensity of integral wind shear wind fields can be simulated. Runway entrances are used as origins of the runway coordinate systems, and approach directions are used as +XR axes of the runway coordinate systems. The method has the advantages that the wind shear models can be designed by means of fusing the vortex rings and the discrete gust models, and the magnitude of the vortex ring central wind speeds of the wind shear models can be changed along with change of the time.

The invention provides a method for determining a downburst crosswind profile. The method comprises the following steps that a downburst crosswind field is determined; ground boundary layer parameters are determined; the downburst crosswind profile is determined. According to the method for determining the downburst crosswind profile, the crosswind profiles within the range of the height smaller than the height of the position with the maximum wind speed are corrected, and the theoretical reference is provided for the engineering design.

The invention discloses a method and system for evaluating the safety of a power transmission tower under downburst and a storage medium. The method comprises the following steps: according to designinformation of the power transmission tower, dividing tower sections of the power transmission tower, setting wind load simulation points, establishing a three-dimensional finite element numerical model of the power transmission tower, and presetting a load information file interface in a model file; determining a downburst wind field structure, completing the simulation of each component of the wind field structure, traversing the wind load simulation points, and generating the wind speed and the wind load at each wind load simulation point; importing the load into a three-dimensional numerical model of the power transmission tower, performing transient dynamic analysis on the tower, and calculating an overall wind vibration coefficient of the power transmission tower structure accordingto an analysis result; according to the weather forecast data, generating downburst parameters, calculating time-varying average wind of each point, amplifying the average wind by using the overall wind vibration coefficient of the structure to obtain an equivalent static wind load, performing quasi-static analysis on the tower, and evaluating the structural safety of the power transmission towerby using an analysis result.

The invention discloses a thunderstorm downburst multifunction experiment simulator. A frame is fixed on a base plate; an upper part is suspended and provided with a vertical blow drier of a variable cross-section of a frequency conversion axial flow fan; vertical columns, two of which form one group and can move on the base plate are respectively arranged on both sides of the frame; a cross beamwhich can move up and down along the groups of the vertical columns is arranged between the two groups of the vertical columns; two parallel trusses pass through a rectangular frame and fixed on the cross beam; idler wheels which are uniformly distributed are arranged on the two trusses; a platform is paved on the idler wheels and can slide along the trusses; two chain wheels are respectively arranged on the middle parts of the two cross beams; the chain wheel is arranged on a rotating shaft of a direct current speed regulation motor; the three chain wheels are connected into an enclosing chain ring by chains; and the central point at the bottom surface of the platform is connected with the chains. Thunderstorm downbursts with different heights, incoming flow wind directions and moving speeds are simulated by changing the height, inclining angle and moving speed of a windarea platform; and the thunderstorm downbursts with different strengths are simulated by changing the rotating speed of the fan. The simulator is suitable for wind resistance experiments under the action of the thunderstorm downbursts.

The invention discloses a downburst identification calculation method based on a near-ground divergence field, which comprises the following steps: firstly, extracting a reflectivity factor and radial speed information of convective echoes detected by a Doppler weather radar, carrying out quality control to obtain speed data and reflectivity factor information after quality control, and then using a linear least square method, obtaining the divergence of multiple elevation angles through calculation, obtaining the distribution of the multi-elevation-angle divergence of the preliminarily deleted convective echoes through a set distance threshold value and a reflectivity factor threshold value, extracting the convergence of the convective echoes and the vertical distribution of the radiation on the basis, and analyzing the space structure of the convective echoes; and obtaining a downburst occurrence probability based on a divergence threshold established by typical downburst examples in warm seasons. According to the method, the defects of downburst monitoring, forecasting and early warning can be overcome, and the requirements of sensitive users for monitoring downburst and forecasting and early warning disastrous gale generated by the sensitive users are met.

The invention discloses a portable device for measuring the three-dimensional wind speed of a wind field, and a manufacturing and application method of the portable device. The device comprises an I-shaped support which consists of an upper end face, a lower end face, and a central part. The central part of the I-shaped support is a streamline shaped housing, and the upper and lower end faces of the I-shaped support are respectively provided with a cover plate. The cover plates are fixed with the streamline shaped housing in a sealed manner, and the interior of the streamline shaped housing is fixedly provided with a clamping groove. The interior of the clamping groove is provided with a probe installation plate, and the probe installation plate is in fixed clamping connection with a clamping groove. The device also comprises a housing installation plate, and the upper part of the housing installation plate is closely provided with a level plate which is hinged to one end of the housing installation plate. The probe installation plate is provided with scale and a plurality of probe installation holes, and positioning grooves are respectively disposed above each probe installation hole. The device is simple in manufacture, is convenient to install, is wide in application range, is low in construction cost, and can achieve the quick measurement of the three-speed wind speed of wind speeds, such as complex mountains and valleys, and downburst.

The invention discloses a two-in-one simulation device of tornado and downburst. The two-in-one simulation device comprises a center wind channel, first flow guide wind channels and second flow guidewind channels, wherein a simulation fan is mounted in the center wind channel; wind inlet ends of the first flow guide wind channels are connected with a wind outlet end of the simulation fan; wind outlet ends of the first flow guide wind channels are connected with a wind inlet end of the simulation fan; a first valve is arranged between the wind inlet end of each first flow guide wind channel and the wind outlet end of the simulation fan; a wind inlet end of each second flow guide wind channel is communicated with the wind outlet end of the simulation fan; a second valve is arranged betweenthe wind inlet end of each second flow guide wind channel and the wind outlet end of the simulation fan; a second wind inlet channel located between the wind inlet end of the simulation fan and the wind outlet end of each first flow guide wind channel is arranged in the center wind channel; a third valve is arranged in each second wind inlet channel; and a fourth valve located among the second wind inlet channels and the wind inlet ends of the first flow guide wind channels is arranged on the center wind channel. The invention also discloses a simulation method using the two-in-one simulationdevice of tornado and downburst.

The invention discloses a method and a system for measuring downburst wind field parameters near a power transmission line. The method comprises the following steps: measuring the wind speed and the wind direction of a downburst of a to-be-determined wind field parameter passing through an observation point; for each group of wind field parameters in the multiple groups of wind field parameters, simulating a wind speed and a wind direction by utilizing a pre-constructed downburst wind field model based on a set downburst life cycle, and fitting the simulated wind speed and the wind direction with the measured wind speed and the measured wind direction to obtain a goodness-of-fit result; and determining the wind field parameter corresponding to the optimal goodness-of-fit result from all the groups as the wind field parameter of the downburst to be determined. The method provides data support for guiding the design work of windproof measures of the power transmission line, improving thepower supply reliability of the power transmission line and researching downburst.

The invention discloses a downburst wind field simulation test device and method based on a boundary layer wind tunnel, wherein the device comprises a bottom frame, a side frame and a top frame whichform a detachable hollow frame structure, and the rear part of the frame is provided with a group of opening and closing plates which are oppositely arranged at the left and right sides and are controlled by a drive system. The group of opening and closing plates and the hollow part of the frame form an air duct, and an inclined plate with adjustable height and inclination angle is transversely arranged in the air duct; by changing the opening and closing and the opening and closing angle of the opening and closing plate and changing the height and inclination angle of the inclined plate, a downburst wind profile and a downburst transient wind speed are simulated in a boundary layer wind tunnel. According to the invention, the problem of carrying out bridge model wind-induced response testresearch under the action of downburst in a boundary layer wind tunnel is solved.

The invention discloses a tornado and downburst integrated physical simulation device. The device comprises a simulation frame, a generator and a moving mechanism, wherein the generator comprises a tornado generator and a downburst generator, the tornado generator and the downburst generator are both arranged on the simulation frame, and the tornado generator and / or the downburst generator can move; the moving mechanism is arranged on the simulation frame and located below the generator, and the moving mechanism at least has four degrees of freedom. The device is advantaged in that the tornado and the downburst which have the characteristics of different forms, moving speeds, moving paths, wider range and the like are obtained, and the tornado and the downburst which are closer to the real tornado and the real downburst in the nature are simulated; wind field characteristics with angles and moving states in a tornado and downburst coupling state can be simulated, and the method is closer to actual conditions; switching of the tornado simulation experiment and the downburst simulation experiment in a short time is achieved, and the time cost and the economic cost for independently conducting the two simulation experiments are reduced.

The embodiment of the invention provides a method for determining a wind shear load caused by downburst when a passenger plane takes off and lands. The method comprises the steps of building a three-dimensional model according to structural information of the passenger plane; establishing a wind field model corresponding to the downburst, and adding the three-dimensional model into the wind fieldmodel according to the position information of the passenger plane; dividing the wind field model into grids in different forms through a preset grid division method; obtaining the edge grid wind pressure of the wind field model and the wall surface boundary type of the wind field model, and calculating the wind pressure data of each grid according to the edge grid wind pressure, the wall surfaceboundary type and the division condition of the grids; and determining the wind pressure data of the passenger plane flying on the flight path according to the flight path information of the passengerplane and the wind pressure data of each grid. By the adoption of the method, the load of wind shear caused by downburst when the passenger plane takes off and lands can be studied, and then the safety of the passenger plane during wind shear caused by downburst can be improved.

The invention relates to the technical field of power transmission circuit design and running maintenance in electric disaster prevention and reduction, in particular to a generation method for a grid wind speed distribution map. According to the method, the grid wind speed distribution map is generated by collecting data such as wide observation data and conforming basic wind speed and basic wind speed correction of non-conventional wind. With the combination of wind speed grading, and the consideration of harm to a power transmission circuit of non-conventional wind such as typhoon and downburst wind, the method provides a mapping manner integrating wind speed observation data and typical wind disaster record of the power transmission circuit; compared with the conventional electric grid wind speed distribution mapping manner, the method is better in applicability and precision.

The invention discloses an integrated wind tunnel simulating mobile tornado and downburst. The integrated wind tunnel comprises a wind tunnel channel in which a simulated test area is provided. A simulated test through hole is arranged on one side of the simulated test area, and a simulated tuyere two-dimensional plane moving device is installed on the simulated test through hole. The simulated tuyere two-dimensional plane moving device comprises a soft shielding belt covering the simulated test through hole, and a simulated tuyere is provided on the soft shielding belt, and the two ends of the soft shielding belt are respectively provided with a simulated tuyere moving mechanism for driving the soft shielding belt to move and enabling the simulated tuyere to move in a two-dimensional plane in the simulated test through hole area. The simulated tuyere moving mechanism comprises an unwinding and rewinding roller for unwinding and rewinding the soft shielding belt and an axial moving mechanism for driving the unwinding and rewinding roller to move in an axial direction thereof. The simulated tuyere moving mechanism also comprises a simulator mount that moves synchronously with the simulated tuyere, and a two-in-one simulator for simulating tornado and downburst is installed on the simulator mount.

The invention discloses an experimental device for simulating dynamic characteristics of a high-voltage transmission conductor under the action of downburst. The experimental device is characterized in that four vertical columns of a rectangular supporting platform are fixed onto the ground, and an axial flow fan is mounted on the rectangular supporting platform. Wind speed is regulated by a frequency converter, and different downburst wind speeds are simulated. The transmission conductor is simulated by the aid of a hollow aluminum tube, and two solid shafts are welded at two ends of the aluminum tube respectively. Two spring-damping systems are suspended at two ends of each solid shaft respectively and fixed to two rectangular frames, and the dynamic characteristics of the hollow aluminum tube at different dip angles, different wind angles and different positions are analyzed by horizontal and vertical relative movement of the rectangular frames. A nozzle and a water supply device are connected with each other and fixed at a 1m position under the axial flow fan, water is sprayed to the hollow aluminum tube to simulate various rainfall states, and the water supply device comprises a water reservoir and a water pump. Rainfall is adjusted by an adjusting valve. A displacement sensor and an acceleration sensor are mounted on the outer sides of the two ends of each solid shaft respectively, and acquired signals are transmitted to an acquisition card through a data line.

The present invention discloses a wind tunnel for simulating the coupling of the wave and the moving downburst under the action of background wind. The wind tunnel comprises: a wind tunnel flow passage; a wind tunnel fan; a wave trough; and a downburst simulation device for simulating the downburst in the moving state. The top of the wind tunnel flow passage is provided with a simulated test through hole above the wave trough, and a two-dimensional plane moving device is installed on the simulated test through hole; the two-dimensional plane moving device comprises a soft shielding belt covering on the simulated test through hole, the soft shielding belt is provided with a simulated tuyere, and both ends of the soft shielding belt are respectively provided with a simulated tuyere moving mechanism; the simulated tuyere moving mechanism comprises a receiving and release roller for receiving and releasing the soft shielding belt and an axial moving mechanism for driving the receiving andrelease roller to move in the axial direction of the simulated tuyere moving mechanism; and the downburst simulation device comprises a downburst simulator mounting frame that moves synchronously withthe simulated tuyere, and the downburst simulator mounting frame is provided with a downburst simulator for simulating the downburst.

An embodiment of the present invention provides a method for determining a load of wind shear caused by a downburst during takeoff and landing of a passenger aircraft. The method includes: establishing a three-dimensional model according to structural information of the passenger aircraft; establishing a wind field model corresponding to the downburst , and add the three-dimensional model to the wind field model according to the position information of the passenger aircraft; divide the wind field model into different forms of grids by the preset grid division method; obtain the edge grid wind pressure of the wind field model and the wind field model For the type of wall boundary, the wind pressure data of each grid is calculated according to the wind pressure of the edge grid, the type of wall boundary and the division of the grid; the flight trajectory information of the passenger aircraft is combined with the wind pressure data of each grid to determine the flight trajectory of the passenger aircraft. Wind pressure data for the flight. The method can provide a method for studying the wind shear load caused by the downburst caused by the take-off and landing of the passenger aircraft, thereby increasing the safety of the passenger aircraft when encountering the wind shear caused by the downburst.

The invention discloses a method for intelligent identification and early warning of downburst based on radar data. First, the optical flow field of the vertical section of the reflectivity factor is analyzed by the optical flow method, and the law of the evolution of the storm core over time is obtained. Then, the Lagrangian mechanical model is used to perform function fitting on the descending process of the storm core top height. Then, the histogram and Barthel coefficient statistical analysis method are used to match and identify the "positive and negative velocity pair" images in the radial velocity field in the middle layer of the storm core, and a series of threshold judgments are combined to finally realize the intelligent early warning of the downburst. Using this method, potential downbursts can be identified in the early stage of storm core uplift and rapid sinking, and the sinking rate of the storm core and the time to reach near the ground can be estimated, so as to realize the intelligent identification of downbursts , early warning.

The invention discloses a physical simulation method for coupling of background wind and mobile downburst. The physical simulation method comprises the following steps: 1) mounting a test model structure on a test bed; 2) starting a wind tunnel fan, forming background wind with set flow speed in a wind tunnel runner, and after the characteristic of a background wind field is stable, measuring thegenerated flow field characteristic of the background wind; 3) starting a downburst simulator to simulate the downburst with set wind power, setting a moving path of the downburst simulator, using a downburst simulator moving device to drive the downburst simulator to move, and enabling the moving path of the downburst simulator to pass through a test model structure from far to near or from nearto far; and 4) measuring the wind field characteristic after downburst coupling under the background wind and mobile state and coupling load borne by the test model structure under different downburstwind field distance conditions. The wind field characteristic and coupling load under the coupling action of the downburst and the background wind can be better studied.

The invention provides a numerical simulation method for a downburst non-stationary fluctuating wind speed. The method comprises the steps of modulating a power spectrum through a time varying average wind speed model of the downburst and an inhomogeneous modulation function related to time frequency so as to obtain the time varying power spectrum of the downburst non-stationary fluctuating wind speed; building a TAR (Terrain Avoidance Radar) time varying model of a stationary stochastic process by further considering the time varying characteristic of an AR (Access Rate) model of the stationary stochastic process; and effectively stimulating the downburst non-stationary fluctuating wind speed by the time varying power spectrum and the TAR time varying model. The relevance of the downburst non-stationary fluctuating wind speed simulated by the numerical simulation method provided by the invention can be weakened along with the increasing of the distances among different positions, the amplitude can be improved to be consistent with the characteristics of a practical wind field as the time varying average wind speed is improved; the power spectrum of the simulated downburst non-stationary fluctuating wind speed has an obvious time varying characteristic, and is consistent with the time varying characteristic of a target time varying spectrum, and the average power spectrum of sample statistics and relevant functions are consistent with the targets.