Low-altitude take-off and landing facility node wind thermal environment simulation method based on TOD mode

Abstract

The application provides a low-altitude take-off and landing facility node wind-thermal environment simulation method based on a TOD mode, relates to the field of smart city design, and specifically comprises the following steps: constructing an initial planning scheme digital model of a target TOD area; performing wind-thermal environment numerical simulation on the initial planning scheme digital model in a typical day and a typical season by using a CFD model; based on the wind-thermal environment numerical simulation result, evaluating the low-altitude operation safety and the ground pedestrian comfort under the initial planning scheme digital model; feeding back the evaluated low-altitude operation safety and ground pedestrian comfort results to the CFD model for iterative simulation and verification until all preset safety and comfort thresholds are met. The technical scheme of the application overcomes the problem in the prior art that in TOD city scale area development, the ground human living environment and the low-altitude operation environment are mutually restricted, and the ground comfort and the low-altitude safety cannot be unified in the same quantitative analysis framework.

Description

Technical Field

[0001] This invention relates to the field of smart city design, specifically to a method for simulating the wind and heat environment of low-altitude take-off and landing facility nodes based on the TOD (Transit-Oriented Development) model. Background Technology

[0002] Transit-Oriented Development (TOD), a public transport-oriented development model, is a key strategy for promoting sustainable urban development. However, its high-density and high-intensity development characteristics can easily lead to the "canyon effect" and "heat island effect," creating localized areas of strong or calm winds and high temperatures, severely impacting pedestrian comfort and building energy consumption. Meanwhile, the rise of the low-altitude economy makes TOD hubs (such as railway stations and subway overpasses) ideal nodes in urban air transport networks. However, complex and turbulent local wind fields pose a serious threat to the takeoff and landing safety of drones and eVTOL (eVTOL) systems, while high-temperature environments can affect aircraft battery efficiency and payload.

[0003] Currently, research and practice in these three fields are disconnected: Urban planners rarely consider the micro-wind environment impact on low-altitude operations when designing TOD hubs.

[0004] Low-altitude operators lack sophisticated risk assessment tools for the complex environment of TOD hubs when selecting take-off and landing sites.

[0005] The wind and heat simulation results of environmental simulation experts are difficult to directly translate into decision-making basis that can be used for low-altitude flight and urban design.

[0006] Therefore, there is a need for an integrated technology that can integrate TOD planning, wind and thermal environment, and low-altitude operations to assist in the site selection and certification of low-altitude aircraft take-off and landing sites, the dynamic management of airway networks, and the simulation method of wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model, taking into account ground comfort. Summary of the Invention

[0007] The main objective of this invention is to provide a method for simulating the wind and heat environment of low-altitude take-off and landing facility nodes based on the TOD model, in order to solve the problem in the existing technology that the ground living environment and the low-altitude operation environment are mutually restrictive in the TOD urban-scale regional development, and that ground comfort and low-altitude safety cannot be unified in the same quantitative analysis framework.

[0008] To achieve the above objectives, this invention provides a method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD (Transit-Oriented Development) model, specifically including the following steps: S1, Construct a digital model of the initial planning scheme for the target TOD area; S2, using CFD models to perform numerical simulations of wind and heat environment on typical days and in typical seasons on the digital model of the initial planning scheme; S3, based on the results of numerical simulation of wind and heat environment, evaluates the safety of low-altitude operation and the comfort of ground pedestrians under the digital model of the initial planning scheme; S4 feeds the results of the assessment of low-altitude operational safety and pedestrian comfort on the ground into the CFD model for iterative simulation and verification until all preset safety and comfort thresholds are met.

[0009] Furthermore, step S1 specifically includes the following steps: S1.1, acquire Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data.

[0010] S1.2 unifies the format of Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data, and performs semantic mapping and entity association on the data in these four fields based on the unified format.

[0011] Furthermore, step S1.2 specifically includes the following steps: S1.2.1 converts the raw data from Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data into RDF format.

[0012] S1.2.2, locate low-altitude infrastructure data to buildings, set the take-off and landing points and search radius of low-altitude aircraft, find building entities near the take-off and landing points, and correlate and locate the take-off and landing points, geographic information and buildings.

[0013] S1.2.3, Define and implement a unified spatial reference system to integrate local coordinates in the BIM. Convert to projected coordinates in GIS : ; in, For translation parameters, For rotation angle parameters, This is the scaling factor.

[0014] S1.2.4, associate building information with traffic network information to find nearby roads around the building.

[0015] S1.2.5, Read the real-time traffic flow information of the surrounding roads and bind the traffic flow information to specific roads.

[0016] S1.2.6, Based on the building and traffic flow information around the building, and by querying all no-fly zones, determine the take-off and landing points and locations of low-altitude aircraft.

[0017] Furthermore, step S2 specifically includes the following steps: S2.1, deploy ultrasonic anemometers and temperature sensors on the rooftops and sidewalls of buildings surrounding the low-altitude aircraft take-off and landing field to collect wind and temperature data in real time. Input the wind and temperature data into the CFD model to perform rolling wind field prediction at the minute or second level, and generate a three-dimensional turbulence intensity and wind shear distribution map for the future time period.

[0018] S2.2, using ENVI-met to conduct numerical simulations, analyze the relationship between microclimate and comfort in the low-altitude aircraft take-off and landing corridor and the TOD radiation area. Furthermore, the low-altitude operation safety assessment in step S3 specifically includes the following steps: S3.1, conduct a downwind turbulence intensity assessment in the takeoff and landing area, activate flight control stabilization mode, or consider closing the takeoff and landing area. The formula for calculating downwind turbulence intensity is: ; in, The intensity of turbulence in the downwind direction. For wind speed standard deviation, This represents the average wind speed.

[0019] S3.2, assess whether the wind shear tolerance of the low-altitude aircraft is exceeded based on the vertical wind shear index. (Vertical wind shear index) The calculation formula is: ; in, For height Wind speed at that location.

[0020] S3.3, using flow velocity scale Assess the impact of thermal turbulence on the vertical motion of low-altitude aircraft: ; in, It is the acceleration due to gravity. For surface sensible heat flux, The height of the mixing layer. This is a virtual temperature. air density, It is a specific heat at constant pressure.

[0021] S3.4, quantify the control margin and evaluate it in the disturbed wind field. The simplified dynamic equation for the additional control force or torque required by the control system to maintain the target's hovering state is as follows: ; in, For the mass of the aircraft, This is the position vector of the aircraft in the inertial coordinate system or the ground coordinate system. For the speed of the aircraft, For the acceleration of the aircraft, For wind speed vectors, It is the gravitational acceleration vector. To control force, It is the nonlinear aerodynamic vector generated by the coupling between the body and the complex wind field.

[0022] Furthermore, the pedestrian comfort assessment in step S3 includes the following steps: S3.5, superimposed correction on the wind speed field: ; in, This is the corrected wind speed field. For spatial coordinates, For time, The background wind field velocity vector, The velocity vector of the downwash flow; S3.6, perform superposition correction on the temperature field: ; in, For the corrected temperature field, The spatial position vector of the pedestrian. Background air temperature field, Temperature disturbances caused by dynamic mixing; S3.7, perform superposition correction on the humidity field: ; in, This is the corrected humidity field. Background relative humidity, This is humidity disturbance caused by the mixing of the downwash stream with air layers of different humidity levels; S3.8, mean radiant temperature Calculation formula: ; in, The Stefan-Boltzmann constant is... Radiation energy absorbed by the human body For emission rate, Air temperature; Superposition correction calculation of the radiation field: ; in, The corrected radiation field. Background mean radiation temperature The change in radiation temperature caused by the shadowing effect. Radiation energy absorbed by the human body.

[0023] Furthermore, the pedestrian comfort assessment in step S3 also includes the following steps: S3.9 Calculate the corrected outdoor standard effective temperature after superimposing wind speed field, temperature field, humidity field, and radiation field. : ; in, Radiation energy absorbed by the human body The human body's metabolic rate. For the thermal resistance of clothing, This is a function for calculating the outdoor standard effective temperature based on the Gagge two-node thermophysiological model. S3.10 Calculate the physiologically equivalent temperature after superimposing wind speed, temperature, humidity, and radiation fields for correction. : ; in, The background wind field velocity vector, This is the physiological equivalent temperature calculation function based on the Munich human body heat balance model; S3.11 Calculate the general thermal climate index after superimposing corrections for wind speed, temperature, humidity, and radiation fields. : ; in, This is a function for calculating a general thermal climate index based on the Fiala human body model.

[0024] The present invention has the following beneficial effects: This invention, during the TOD (Transit-Oriented Development) urban-scale regional planning and design phase, can proactively avoid unacceptable low-altitude wind risks or ground thermal stress caused by morphological layout, preventing a passive situation after completion. It is synergistic, breaking down technical barriers in planning, transportation, environment, and aviation, finding a common language and collaborative path to improve ground comfort and ensure low-altitude safety. It is scientific, providing quantitative scientific basis for the selection of low-altitude take-off and landing sites based on fluid dynamics simulations, rather than relying solely on experience, greatly improving the bottom line of operational safety. It is intelligent, with extended dynamic operation management functions enabling the built environment to possess "sensing-analysis-response" capabilities, proactively adapting to real-time changes in the environment and serving dynamic low-altitude traffic flows. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A flowchart of a method for simulating the wind and heat environment of a low-altitude take-off and landing facility node based on the TOD model is shown. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0027] like Figure 1 The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model, as shown, specifically includes the following steps: S1, Construct a digital model of the initial planning scheme for the target TOD area.

[0028] S2. The CFD model is used to perform numerical simulations of the wind and heat environment on typical days and in typical seasons on the digital model of the initial planning scheme.

[0029] S3, based on the results of numerical simulation of wind and heat environment, evaluates the safety of low-altitude operation and the comfort of ground pedestrians under the digital model of the initial planning scheme.

[0030] S4 feeds the results of the assessment of low-altitude operational safety and pedestrian comfort on the ground into the CFD model for iterative simulation and verification until all preset safety and comfort thresholds are met.

[0031] Specifically, step S1 includes the following steps: S1.1, acquire Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data.

[0032] S1.2 unifies the format of Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data, and performs semantic mapping and entity association on the data in these four fields based on the unified format.

[0033] Specifically, step S1.2 includes the following steps: S1.2.1 Convert the raw data of Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data into RDF format; S1.2.2, locate low-altitude infrastructure data to buildings, set the take-off and landing points and search radius of low-altitude aircraft, find building entities near the take-off and landing points, and correlate and locate the take-off and landing points, geographic information and buildings. S1.2.3, Define and implement a unified spatial reference system to integrate local coordinates in the BIM. Convert to projected coordinates in GIS To achieve the integration of BIM and GIS: ; in, For translation parameters, For rotation angle parameters, This is the scaling factor.

[0034] S1.2.4, link building information with traffic network information to find nearby roads around the building; S1.2.5, Read the real-time traffic flow information of the adjacent roads around the building and bind the traffic flow information to specific roads; S1.2.6, Based on the building and traffic flow information around the building, and by querying all no-fly zones, determine the take-off and landing points and locations of low-altitude aircraft.

[0035] Heterogeneous data from four fields—BIM, GIS, traffic flow, and low-altitude infrastructure—are transformed into RDF maps, and a standard ontology definition is established. In the BIM field: using ifcOWL ontology to describe building components and their detailed geometric properties.

[0036] In the GIS field: CityGML-RDF is used to describe terrain, administrative boundaries, and macro-level urban infrastructure.

[0037] Traffic flow: Construct TrafficOnto and define dynamic attributes such as road segments, nodes, flow speed, and flow rate.

[0038] Low-altitude infrastructure: Construct LowAltOnto, defining takeoff and landing fields, waypoints, airspace corridors, and obstacle avoidance surfaces.

[0039] Specifically, step S2 includes the following steps: S2.1, deploy ultrasonic anemometers and temperature sensors on the rooftops and sidewalls of buildings around the low-altitude aircraft take-off and landing field to collect wind and temperature data in real time. Input the wind and temperature data into the CFD model to perform rolling wind field prediction at the minute or second level, and generate a three-dimensional turbulence intensity and wind shear distribution map for the future time period. S2.2 Numerical simulation was conducted using ENVI-met to analyze the relationship between microclimate and comfort in the low-altitude aircraft take-off and landing corridor and the TOD radiation area; modeling, parameter setting, calculation and result analysis were completed in ENVI-met software to obtain the distribution of air temperature, relative humidity and wind direction and speed in the study area; Specifically, the low-altitude operation safety assessment in step S3 includes the following steps: S3.1, conduct a downwind turbulence intensity assessment in the takeoff and landing area, activate flight control stabilization mode, or consider closing the takeoff and landing area. The formula for calculating downwind turbulence intensity is: ; in, The intensity of turbulence in the downwind direction. For wind speed standard deviation, This represents the average wind speed.

[0040] S3.2, assess whether the wind shear tolerance of the low-altitude aircraft is exceeded based on the vertical wind shear index. (Vertical wind shear index) The calculation formula is: ; in, For height Wind speed at that location.

[0041] S3.3, using flow velocity scale Assess the impact of thermal turbulence on the vertical motion of low-altitude aircraft: ; in, It is the acceleration due to gravity. For surface sensible heat flux, The height of the mixing layer. This is a virtual temperature. air density, It is a specific heat at constant pressure.

[0042] S3.4, quantify the control margin and evaluate it in the disturbed wind field. The simplified dynamic equation for the additional control force or torque required by the control system to maintain the target's hovering state is as follows: ; in, For the mass of the aircraft, This is the position vector of the aircraft in the inertial coordinate system or the ground coordinate system. for The first derivative with respect to time, i.e., the velocity of the aircraft. for The second derivative with respect to time, i.e., the acceleration of the aircraft, For wind speed vectors, It is the gravitational acceleration vector. The total force vector output by the control system, i.e., the control force. It is the nonlinear aerodynamic vector generated by the coupling between the body and the complex wind field.

[0043] Specifically, the pedestrian comfort assessment in step S3 includes the following steps: S3.5, superimposed correction on the wind speed field: ; in, This is the corrected wind speed field. For spatial coordinates, For time, The background wind field velocity vector, The velocity vector of the downwash flow; S3.6, perform superposition correction on the temperature field: ; in, For the corrected temperature field, The spatial position vector of the pedestrian. Background air temperature field, Temperature disturbance caused by dynamic mixing; S3.7, perform superposition correction on the humidity field: ; in, This is the corrected humidity field. Background relative humidity, This is humidity disturbance caused by the mixing of the downwash stream with air layers of different humidity levels; S3.8, mean radiant temperature Calculation formula: ; in, The Stefan-Boltzmann constant is... Radiation energy absorbed by the human body For emission rate, Air temperature; Superposition correction calculation of the radiation field: ; in, The corrected radiation field. Background mean radiation temperature The change in radiation temperature caused by the shadowing effect. Radiation energy absorbed by the human body.

[0044] Specifically, the pedestrian comfort assessment in step S3 also includes the following steps: S3.9 Calculate the corrected outdoor standard effective temperature after superimposing wind speed field, temperature field, humidity field, and radiation field. : ; in, Radiation energy absorbed by the human body The human body's metabolic rate. For the thermal resistance of clothing, This is a function for calculating the outdoor standard effective temperature based on the Gagge two-node thermophysiological model. S3.10 Calculate the physiologically equivalent temperature after superimposing wind speed, temperature, humidity, and radiation fields for correction. : ; in, The background wind field velocity vector, This is the physiological equivalent temperature calculation function based on the Munich human body heat balance model; S3.11 Calculate the general thermal climate index after superimposing corrections for wind speed, temperature, humidity, and radiation fields. : ; in, This is a function for calculating a general thermal climate index based on the Fiala human body model.

[0045] Based on physiological equivalent temperature, standard effective temperature, general thermal climate index, and thermal sensation voting, a thermal comfort response mapping table corresponding to the operating scenario is established.

[0046] The method provided by this invention shifts the evaluation process from qualitative description to quantitative, computable, and verifiable engineering science analysis. This provides a solid mathematical foundation for building morphology and layout, site selection and certification of low-altitude aircraft take-off and landing sites, dynamic management of airway networks, and environmentally friendly urban design.

[0047] Create a "safety-comfort" overlay map to identify high-risk spatiotemporal regions. and Using threshold values ​​as constraints, an optimization algorithm for low-altitude aircraft takeoff and landing site selection is proposed. A design optimization based on quantization results is also presented.

[0048] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD (Transit-Oriented Development) model, characterized in that, Specifically, the steps include the following: S1, Construct a digital model of the initial planning scheme for the target TOD area; S2, using CFD models to perform numerical simulations of wind and heat environment on typical days and in typical seasons on the digital model of the initial planning scheme; S3, based on the results of numerical simulation of wind and heat environment, evaluates the safety of low-altitude operation and the comfort of ground pedestrians under the digital model of the initial planning scheme; S4 feeds the results of the assessment of low-altitude operational safety and pedestrian comfort on the ground into the CFD model for iterative simulation and verification until all preset safety and comfort thresholds are met.

2. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 1, characterized in that, Step S1 specifically includes the following steps: S1.1, acquire Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data; S1.2 unifies the format of Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data, and performs semantic mapping and entity association on the data in these four fields based on the unified format.

3. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 2, characterized in that, Step S1.2 specifically includes the following steps: S1.2.1 Convert the raw data of Building Information Modeling (BIM), Geographic Information System (GIS) data, public transportation flow data, and low-altitude infrastructure data into RDF format; S1.2.2, locate low-altitude infrastructure data to buildings, set the take-off and landing points and search radius of low-altitude aircraft, find building entities near the take-off and landing points, and correlate and locate the take-off and landing points, geographic information and buildings. S1.2.3, Define and implement a unified spatial reference system to integrate local coordinates in the BIM. Convert to projected coordinates in GIS : ； in, For translation parameters, For rotation angle parameters, The scaling factor; S1.2.4, link building information with traffic network information to find nearby roads around the building; S1.2.5, Read the real-time traffic flow information of the adjacent roads around the building and bind the traffic flow information to specific roads; S1.2.6, Based on the building and traffic flow information around the building, and by querying all no-fly zones, determine the take-off and landing points and locations of low-altitude aircraft.

4. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 1, characterized in that, Step S2 specifically includes the following steps: S2.1, deploy ultrasonic anemometers and temperature sensors on the rooftops and sidewalls of buildings around the low-altitude aircraft take-off and landing field to collect wind and temperature data in real time. Input the wind and temperature data into the CFD model to perform rolling wind field prediction at the minute or second level, and generate a three-dimensional turbulence intensity and wind shear distribution map for the future time period. S2.2, using ENVI-met to conduct numerical simulations, analyze the relationship between microclimate and comfort in the low-altitude aircraft take-off and landing corridor and the TOD radiation area.

5. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 1, characterized in that, Step S3, the safety assessment for low-altitude operations, specifically includes the following steps: S3.1, conduct a downwind turbulence intensity assessment in the takeoff and landing area, activate flight control stabilization mode, or consider closing the takeoff and landing area. The formula for calculating downwind turbulence intensity is: ； in, The intensity of turbulence in the downwind direction. For wind speed standard deviation, Average wind speed; S3.2, assess whether the wind shear tolerance of the low-altitude aircraft is exceeded based on the vertical wind shear index. (Vertical wind shear index) The calculation formula is: ； in, For height Wind speed at the location; S3.3, using flow velocity scale Assess the impact of thermal turbulence on the vertical motion of low-altitude aircraft: ； in, It is the acceleration due to gravity. For surface sensible heat flux, The height of the mixing layer. This is a virtual temperature. air density, It is a specific heat at constant pressure; S3.4, quantify the control margin and evaluate it in the disturbed wind field. The simplified dynamic equation for the additional control force or torque required by the control system to maintain the target's hovering state is as follows: ； in, For the mass of the aircraft, This is the position vector of the aircraft in the inertial coordinate system or the ground coordinate system. For the speed of the aircraft, For the acceleration of the aircraft, For wind speed vectors, It is the gravitational acceleration vector. To control force, It is the nonlinear aerodynamic vector generated by the coupling between the body and the complex wind field.

6. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 5, characterized in that, Step S3, the assessment of pedestrian comfort on the ground, includes the following steps: S3.5, superimposed correction on the wind speed field: ； in, This is the corrected wind speed field. For spatial coordinates, For time, The background wind field velocity vector, The velocity vector of the downwash flow; S3.6, perform superposition correction on the temperature field: ； in, The corrected temperature field, The spatial position vector of the pedestrian. Background air temperature field, Temperature disturbance caused by dynamic mixing; S3.7, perform superposition correction on the humidity field: ； in, This is the corrected humidity field. Background relative humidity, This is humidity disturbance caused by the mixing of the downwash stream with air layers of different humidity levels; S3.8, mean radiant temperature Calculation formula: ； in, The Stefan-Boltzmann constant is... Radiation energy absorbed by the human body For emission rate, Air temperature; Superposition correction calculation of the radiation field: ； in, The corrected radiation field. Background mean radiation temperature The change in radiation temperature caused by the shadowing effect. Radiation energy absorbed by the human body.

7. The method for simulating the wind and thermal environment of low-altitude take-off and landing facility nodes based on the TOD model according to claim 6, characterized in that, Step S3, the assessment of pedestrian comfort on the ground, also includes the following steps: S3.9 Calculate the corrected outdoor standard effective temperature after superimposing wind speed field, temperature field, humidity field, and radiation field. : ； in, Radiation energy absorbed by the human body The human body's metabolic rate. For the thermal resistance of clothing, This is a function for calculating the outdoor standard effective temperature based on the Gagge two-node thermophysiological model. S3.10 Calculate the physiologically equivalent temperature after superimposing wind speed, temperature, humidity, and radiation fields for correction. : ； in, The background wind field velocity vector, This is the physiological equivalent temperature calculation function based on the Munich human body heat balance model; S3.11 Calculate the general thermal climate index after superimposing corrections for wind speed, temperature, humidity, and radiation fields. : ； in, This is a function for calculating a general thermal climate index based on the Fiala human body model.

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