305 results about "Aerodynamic drag" patented technology

The invention provides a whole vehicle point cloud windage coefficient prediction method and system based on multi-scale learning and convolution, and relates to the technical field of windage coefficient prediction, and the method specifically comprises the steps: obtaining point cloud data of a whole vehicle model, and carrying out the preprocessing of the point cloud data; sampling the preprocessed point cloud data through a farthest point sampling method so as to reserve geometric key points; constructing a convolutional neural network model, inputting the point cloud data into the network, sequentially carrying out two times of multi-scale convolution operations, extracting local details and global structure features through convolution kernels of different scales, mapping the features from low dimensions to 512 dimensions and expanding the features to 1024 dimensions, and completing feature aggregation; the feature expression capability is further enhanced through two-layer convolution; utilizing a maximum pooling layer to aggregate global features, and performing dimension reduction on the features through a multi-layer perceptron; introducing a physical guidance attention mechanism to physically constrain the spatial weight of the features; and establishing a mapping relation between the point cloud features and the wind resistance coefficient through a full connection layer, and outputting a wind resistance coefficient prediction result. According to the invention, the accuracy and efficiency of wind resistance coefficient prediction can be improved.

An active air flap system mounted in a predetermined portion of a vehicle, includes: a housing, a flap mounted on the housing to be relatively movable, an actuator coupled to the at least one flap and configured to drive the at least one flap, and a power transfer mechanism engaging the actuator and the flip and configured to transfer power from the actuator to the at least one flap so that the at least one flap performs a dual operation of a sliding movement operation and a rotation operation of rotating around a predetermined rotation axis, preventing the occurrence of design heterogeneity and the air resistance caused by forming the space between the at least one flap and the radiator grill, and improving shielding properties.

The invention provides an adjustable air-breathing power ultra-low orbit satellite configuration. The adjustable air-breathing power ultra-low orbit satellite configuration comprises an adjustable closed head part, a body, a stable wing surface and a contraction tail part, the adjustable closing head and the contraction tail are connected to the two opposite ends of the body respectively, and the stable wing face is connected to the side, close to the contraction tail, of the body. The design that the adjustable closing head is an openable / closable head is adopted, the adjustable closing head is a spherical head after being closed when a satellite does not need to inhale, and resistance is reduced; and after being expanded, the air inlet channel can be contracted into an inwards-concave air inlet channel, so that active compression of air is achieved. Therefore, task requirements under different flight heights can be met through flexible switching of the inspiration working mode and the non-inspiration working mode, the aerodynamic resistance of the satellite in an ultra-low orbit is effectively reduced, and the hang time of the satellite is prolonged.

The invention relates to the field of wind resistance prediction, in particular to a construction method and device of an automobile wind resistance prediction model, electronic equipment and a medium. The construction method of the automobile wind resistance prediction model comprises the steps of obtaining sample data of automobile wind resistance, wherein the sample data comprises automobile appearance point cloud data and an automobile wind resistance coefficient; in response to a to-be-trained model, obtaining prediction data of the sample data; the model to be trained comprises a PointNet + + model; model parameters of the to-be-trained model are updated to reduce loss of the prediction data and the sample data, a wind resistance prediction model is obtained, and the wind resistance prediction model is used for responding to the automobile appearance point cloud data and predicting the automobile wind resistance coefficient. The method is high in model prediction precision and prediction efficiency.

The invention provides a vehicle point cloud wind resistance coefficient integrated prediction method and system based on feature recognition, and relates to the technical field of wind resistance coefficient prediction, and the method specifically comprises the steps: obtaining the point cloud data of a vehicle model, and carrying out the preprocessing of the point cloud data; constructing a classification network model, inputting the preprocessed point cloud data into the classification network model for vehicle type classification, and outputting vehicle type categories and probability values corresponding to the vehicle type categories; constructing a plurality of specific models in one-to-one correspondence with the vehicle type categories and a generalization model; whether the maximum probability value in the vehicle type classification labels is higher than a preset threshold value or not is judged, if yes, a specific model corresponding to the vehicle type category is selected to conduct wind resistance coefficient prediction, and if not, a generalization model is selected to conduct wind resistance coefficient prediction; according to the method, the vehicle types are classified and matched with the proper wind resistance coefficient prediction model, so that the prediction speed and the accuracy of a prediction result are greatly improved.

The invention relates to a vehicle control apparatus and a vehicle control method. The vehicle control apparatus may calculate a sum of power consumed according to at least one or any combination of power consumed due to air resistance, power consumed due to operation of a cooling fan that increases airflow introduced into an engine compartment of a vehicle, or power consumed due to operation of an air conditioner, and control at least one or any combination of flaps or cooling fans that open and close an air inlet of the engine compartment such that the sum of power consumed is minimized in response to ensuring a target air flow indicative of an air flow required through a condenser or a radiator of the air conditioner depending on vehicle operation.

The embodiment of the invention provides a vehicle aerodynamic resistance control method and device, a vehicle and a storage medium, the vehicle comprises air supply equipment and an empennage which are arranged at the tail, and the method comprises the steps that the vehicle speed and the tail static pressure of the vehicle are obtained, and the braking state of the vehicle is determined; judging whether the vehicle meets an aerodynamic resistance reduction condition or not according to the vehicle speed and the tail static pressure of the vehicle; according to the vehicle speed and the vehicle braking state, whether the vehicle meets the aerodynamic resistance increasing condition or not is judged; if the vehicle meets the aerodynamic resistance reduction control condition, air supply equipment and an empennage of the vehicle are adjusted to reduce the aerodynamic resistance of the vehicle; if the vehicle meets the control condition for increasing the aerodynamic resistance, the aerodynamic resistance of the vehicle is increased, so that the aerodynamic resistance of the vehicle can be controlled in real time by controlling the air supply equipment and the empennage mounted at the tail part of the vehicle, and the aerodynamic resistance is reduced when the vehicle runs at a high speed so as to improve the endurance; and when the vehicle is braked, the pneumatic resistance is increased to shorten the braking distance.

The invention discloses a wind turbine fairing optimization design method, which relates to the technical field of fluid machinery and engineering, and comprises the following steps: a basic parameter acquisition and working condition defining step: collecting wind turbine model parameters, and measuring the wind condition of an operation area; the flow guide cover is divided into a windward section, a middle section and a wake flow section; a multi-objective optimization system construction step: determining aerodynamic resistance, structural strength, weight and wake flow influence optimization objectives; an optimization algorithm iteration solving step, wherein an improved non-dominated sorting genetic algorithm is adopted; a simulation verification and parameter correction step: selecting a scheme to perform CFD and finite element simulation; and a physical prototype manufacturing and performance testing step: manufacturing a prototype, and carrying out wind tunnel and field testing. The design efficiency of the air guide sleeve is improved, systematicness is optimized, pneumatic, structure and weight multi-target balance is achieved, cross-model universality is improved, and the problems that traditional design is dependent on experience and unbalanced in performance are solved.

The invention relates to a wheel device, a vehicle having the wheel device and a method of controlling the wheel device. The wheel device comprises a wheel body, a cover element and a transmission assembly. The wheel body is provided with a plurality of spokes which are arranged at intervals at a preset angle, and a through opening through which air can pass is formed between every two adjacent spokes; the cover element can cover the side face of the wheel body in a rotating mode relative to the wheel body around the rotating axis of the wheel body and is provided with at least one hole opening area. A transmission assembly is disposed between the wheel body and the shroud element and is configured to rotate the shroud element relative to the wheel body about a rotational axis of the wheel body when a rotational speed of the wheel body is greater than a predetermined threshold, therefore, the through opening of the wheel body is converted from an open state in which the through opening overlaps with the orifice area to a blocked state in which the through opening does not overlap with the orifice area. The invention has the advantages of reducing air resistance, increasing endurance mileage or fuel efficiency, and improving cooling performance, braking performance and appearance design.

A rear impact guard includes at least one vertical member, and a horizontal member connected to a distal end of the at least one vertical member, the horizontal member having a plurality of through passages allowing for air flow through the horizontal member.

Embodiments of the invention are directed to systems and methods for reducing drag on an aircraft. The aircraft can include at least one propulsion system with rotor blades configured to reduce aerodynamic drag when the propulsion system is deactivated. To reduce the amount of drag, the rotor blades can be locked into an aerodynamic position, and prevented from passively spinning. Additionally, the rotor blades can be configured to have angular positions that reduce drag. For example, the rotor blades as a group may be configured to generally point toward and / or away from an airflow current.

The invention relates to the technical field of road load testing, in particular to an automobile road load testing method and system. The method comprises the steps that a wind tunnel test environment is arranged, in the wind tunnel test environment, wheels of a to-be-tested vehicle are arranged on a wheel driving unit, a vehicle body is connected with a six-component force measuring balance through a vehicle skirt restraint system, and the vehicle skirt restraint system adopts a floating mode; airflow is controlled to blow through the surface of the vehicle, the central belt simulates ground motion, and the central belt and the wheel driving unit are synchronous with wind speed; the to-be-tested vehicle moves at each reference vehicle speed; after each reference vehicle speed is stable, determining the aerodynamic resistance of the to-be-measured vehicle at each reference vehicle speed based on a balance force transducer; meanwhile, based on the wheel driving unit, the rolling resistance of the wheel is determined; and determining the road load of the to-be-tested vehicle according to the rolling resistance and the aerodynamic resistance. According to the invention, the road load can be obtained more accurately, efficiently and quickly.

The invention relates to an ornithopter, which comprises: a fuselage base; the wings are symmetrically arranged on two opposite sides above the plate surface of the fuselage base 1; the at least two groups of connecting assemblies are arranged on the fuselage base and are connected with the fuselage base and the wings; the first driving assemblies are arranged on the fuselage base and drive the wings to rotate around the axis parallel to the first direction; the second driving assemblies are arranged on the fuselage base and drive the wings to swing around the axis parallel to the second direction; the control assembly is arranged on the machine body base and electrically connected with the first driving assembly and the second driving assembly. According to the ornithopter, vertical flapping and inclined rotation relative to the horizontal plane of the wings are controlled through the first driving assembly and the second driving assembly respectively, air resistance borne by the wings during vertical flapping is changed, and therefore lift force, forward force and / or steering force are provided for the ornithopter; therefore, the flapping-wing air vehicle realizes flexible turning motion.

An aerial vehicle (AV) 100 includes a rotor system 150 with a set of rotor arms 152 and a set of propellers 154 to provide a lift force during a vertical take-off of the AV 100; and a set of landing gears movably coupled to the rotor arms 152 for movement between a deployed position to support the aerial vehicle 100 during landing and take-off, and a retracted position to form an enclosure 210 around the set of propellers 154 to reduce aerodynamic drag during a forward movement of the AV 100 after the vertical take-off. The sets of landing gears can includes a pair of L-shaped landing gears 200, a C-shaped cross sectional landing gears, an another C-shaped cross sectional landing gears, a U-shaped slidable landing gears, and a flap-shaped slidable landing gears.

The invention discloses an aircraft landing buffer device which comprises pneumatic resistance speed reduction devices, a distributed bionic four-foot adjusting mechanism, a buffer layer and a central controller which are symmetrically arranged in the circumferential direction, and all modules achieve multi-stage buffer control through position layout and function coupling. The aerodynamic resistance speed reduction device is circumferentially arranged on the edge of the chassis, aerodynamic pre-deceleration is provided through a resistance plate with an adjustable unfolding angle, landing kinetic energy is consumed, and crosswind loads are balanced. The bionic four-foot adjusting mechanisms are distributed at the four corners of the chassis, joint rigidity and friction damping are adjusted in real time based on terrain perception, and uniform distribution of impact loads of different terrains is achieved. The buffer layer is located between the chassis and the passenger compartment, and gradient energy consumption is carried out to control the impact overload peak value. By means of intelligent angle adjustment and crosswind compensation of the pneumatic resistance device, the low-altitude speed reduction efficiency and the wind resistance capacity are improved; the gradient energy consumption design of the bionic four feet and the buffer layer solves the adaptability problem of a traditional device landing on the hard ground or the soft ground.

The invention belongs to the technical field of high-speed train aerodynamic optimization, and particularly relates to a train pneumatic drag reduction and wake flow regulation and control device and method based on bionic shark fins. The device comprises a base, the base is arranged on the lower surface of the vehicle body fairing through a plurality of bolts, a fin plate is arranged on the base, and a fixing block is arranged at the bottom of the fin plate; the base is provided with a plurality of limiting and locking mechanisms, the fin plate is limited through the limiting and locking mechanisms, the limiting and locking mechanisms are provided with driving mechanisms, the driving mechanisms are connected with rotating shafts, and the rotating shafts are connected with the fixing blocks and used for driving the fin plate to rotate; a lateral reinforcing plate is arranged on the outer side of the base, a pneumatic compensation plate is arranged between the lateral reinforcing plate and the fin plate, and the pneumatic compensation plate is fixedly connected with the base plate. By dynamically adjusting the attack angle and clearance compensation of an additional device on the surface of the vehicle body, aerodynamic resistance is reduced, wake flow stability is improved, and self-adaptive optimization under complex working conditions is achieved.

The invention provides a micro structure control method for resistance reduction of a higher-speed-level train. The micro structure control method specifically comprises the steps that a closely-arranged micro ridge-shaped two-dimensional structure with ridge lines parallel to the length direction of the train is designed; performing CFD numerical experiment based on the k-omega SST turbulence model and the microstructure numerical modeling boundary, and analyzing the flow characteristics of different sizes of microstructure surfaces on the high-speed train at the operation speed of 400km / h to obtain the optimal bionic microstructure cross section size; by analyzing a flow field of a simplified model of the high-speed train, summarizing flow characteristics of streaming of the high-speed train and combining flow control characteristics of the bionic microstructures, the bionic microstructures are arranged in a straight section area of the train, and the bionic microstructures are not arranged in streamline areas of a head train and a tail train. The method is reasonable in conception, can be applied to a high-speed train with the speed of 400 km / h, optimizes flow characteristics and reduces aerodynamic resistance by arranging microstructures with specific shapes and sizes on the surface of the train, and therefore the running efficiency and stability of the train are improved.

The invention relates to the technical field of wired power flight transportation equipment, in particular to a wired power low-altitude aircraft which comprises an aircraft body, a cargo carrying box used for transporting cargoes is arranged at the bottom of the aircraft body, and a power cable is arranged on one side of the aircraft body; the lifting force counteracting device comprises a descending deflection assembly arranged on one side of the aircraft body, a first magnet is arranged on the descending deflection assembly, a matching assembly is arranged on one side of the descending deflection assembly, a second magnet is arranged on the matching assembly, and the first magnet and the second magnet are located at the same horizontal height and are in the state that like poles repel each other. A horizontal force counteracting device is arranged on one side of the lifting force counteracting device. According to the device, when the wired electric aircraft ascends or flies in the horizontal direction, air resistance borne by a power cable in the moving process of the aircraft is effectively counteracted, so that the pulling force applied to the aircraft by the power cable is reduced, and the effect that the aircraft flies stably is ensured.

The invention relates to the technical field of digital twinning, and particularly discloses a cab wind resistance contour optimization method based on digital twinning, which comprises the following steps: S1, establishing a three-dimensional model of a cab, and calculating front wind resistance according to an included angle between planes; s2, marking a standard plane in the initial model, obtaining the air velocity of the standard plane, calculating the air pressure of the standard plane, and calculating the rising force based on the air pressure; s3, marking an influence surface in the initial model, obtaining the air velocity of the influence surface, calculating the air pressure of the influence surface, and calculating the downforce based on the air pressure; and S4, calculating the friction force and the wind resistance coefficient of the initial model, and selecting an optimal model based on the wind resistance coefficient. According to the method, the effect of the optimized cab wind resistance contour is judged through a more reasonable method, so that the cab wind resistance contour with the best effect is selected, the air resistance during vehicle running is reduced, the load and fuel consumption of an engine are reduced, and the running cost is saved.

Systems and methods for determining the impact of air resistance on the power being produced by a body motion are disclosed. In one aspect, a method includes measuring positions and orientations of a portion of the body in motion. The method further includes measuring pressure experienced by the portion of the body in motion. The motion further includes calculating a static pressure based on the measured pressures and correlated position and orientation measurements. The method further includes calculating a maximum pressure and calculating an air induced power exerted on the body in motion.

The invention discloses an anti-drag foldable flapping-wing micro-aircraft, and relates to the technical field of aircrafts. Comprising a fuselage with an oval head, and an empennage is mounted at one end of the fuselage; the power structure is arranged in the fuselage, and the power structure is used for adjusting the folding wings; the folding mechanisms are arranged on the two sides of the power structure, and the folding mechanisms are used for folding the folding wings; a plurality of mounting holes are formed in the top end of the body, solar panels are mounted in the mounting holes, a mobile power supply is mounted on one side of the inner wall of the body, and a notch is formed in the inner wall of the bottom end of the body. According to the aircraft, the head of the aircraft body is arranged to be oval, air resistance can be reduced, the flight efficiency can be improved, airflow can be effectively smoothed, the air resistance encountered by the aircraft in the flight process is reduced, the stability of the aircraft in the air is better, airflow interference is reduced, and the flight stability is improved; the heat of the power structure can be effectively dissipated when the aircraft flies.

To provide a simulator capable of appropriately reproducing acceleration acting on a user.SOLUTION: The control unit of the simulator receives the squaring angle detected by the first detecting unit or the squaring angle calculated from the angular velocity detected by the first detecting unit and the angle of attack detected by the second detecting unit, calculating an inertial force generated in the support plate in the turn action from an equation of motion related to a gravity of the user acting on the support plate, a frictional force between the support plate and the reference surface, and an air resistance acting on the user in the turn action, using a friction coefficient between the support plate and the reference surface in the turn action as a sum of a first friction coefficient between the support plate and the reference surface in a carving turn action in which the turn action is performed in a state of being inclined in the roll direction and a second friction coefficient between the support plate and the reference surface in a squatting turn action in which the turn action is performed so as to rotate in the yaw direction; The turning radius of the support plate in the turn operation is calculated, and the driving part is controlled based on the calculation result.SELECTED DRAWING: Figure 1

The invention relates to a bicycle wind tunnel testing device and method. The bicycle wind tunnel testing device comprises a base; the first roller and the second roller are respectively arranged on the base and are used for enabling a front wheel of a to-be-tested bicycle to be in contact with the first roller and enabling a rear wheel of the to-be-tested bicycle to be in contact with the second roller; a pair of brackets connected to the base and supporting the bicycle from both sides of the bicycle, respectively, each bracket of the pair of brackets including an inner outer fairing and an inner support disposed within the outer fairing, and a cross-sectional shape of the outer fairing being formed in a streamline shape that minimizes wind resistance received by each bracket; and the force measuring device is used for measuring an aerodynamic load including wind resistance in a wind tunnel test. Through the testing device and method disclosed by the invention, the air resistance of the bicycle and a rider under the similar real condition can be measured, and the capability range of wind tunnel testing can be expanded.

The invention relates to a vehicle sliding resistance decomposition method and device, a storage medium and a program product, and relates to the technical field of vehicles. The technical problem of how to accurately decompose the sliding resistance in the prior art is at least solved. The method comprises the following steps: acquiring sliding resistance and rolling resistance of a vehicle; wherein the sliding resistance is the sum of the rolling resistance, the air resistance and the internal resistance of the whole vehicle, and the internal resistance of the whole vehicle is the resistance generated by a transmission system in the running process of the vehicle. A torque of a driveline in a vehicle is obtained. And determining the internal resistance of the whole vehicle based on the torque of the transmission system. And determining the air resistance of the vehicle based on the sliding resistance and the internal resistance of the whole vehicle.

The present invention is directed to a novel vehicle configuration with at least one tunnel (2) enclosed inside the vehicle body, wherein the tunnel (2) comprises an inlet (9), an outlet (10) and a middle section forming a neck (14) of the tunnel (2), wherein the tunnel (2) is narrower at the neck (14) than at the inlet (9) and outlet (10) to achieve Venturi effect The tunnel (2) is applicable to any vehicle type, with all propulsion systems, and especially to electric sports cars. The vehicle configuration with the at least one enclosed tunnel (2) has the following main advantages: reduced drag coefficient, increased downforce, increased vehicle structural rigidity, and better stability of the vehicle travelling at high speeds.

This invention discloses a landing gear and an aircraft, relating to the field of aircraft structural components. The landing gear includes a nose landing gear and two main landing gears. The nose landing gear is located at the front of the fuselage and includes a nose wheel and a nose shock strut. One end of the nose shock strut is connected to the fuselage and located inside the fuselage, while the other end extends outside the fuselage and is elastically connected to the nose wheel. The two main landing gears are respectively located on opposite sides of the fuselage. Each main landing gear includes a rocker arm, a main shock absorber, and a main wheel. The rocker arm has a hinged end and a free end, respectively. The hinged end is hinged to the inside of the fuselage so that the rocker arm can only swing along the aircraft's heading. The free end is connected to the main wheel. This invention incorporates part of the nose landing gear structure inside the fuselage and directly hinges the rocker arms of the main landing gear to the fuselage, reducing the overall frontal area of ​​the landing gear, decreasing the aerodynamic drag and overall weight of the aircraft, thereby improving the overall performance and range of the aircraft.

This invention discloses a method for calculating the fuel consumption saving rate of a vehicle platoon based on topology and dynamic characteristics. The method includes establishing a vehicle dynamics model, an external flow field model, and a mathematical analysis model of the fuel consumption saving rate of the vehicle platoon. The proposed method conducts simulation experiments for different parameters such as longitudinal vehicle spacing, lateral vehicle offset distance, and vehicle speed. By analyzing the influence of longitudinal vehicle spacing, lateral vehicle offset distance, and vehicle speed on the vehicle's aerodynamic drag coefficient, the functional relationship between the vehicle platoon's aerodynamic drag coefficient and the above parameters is determined. Furthermore, the functional relationship between the aerodynamic drag coefficient and the fuel consumption saving rate is determined to calculate the vehicle platoon's fuel consumption saving rate.

The present invention relates to a grid drag reduction mode switching valve in an adjustable mechanism of an adaptive cycle engine. The mode switching valve is located in the second outer conduit of the engine and is driven by a hydraulic actuator. The sealing is achieved using a sealing strip and a load-bearing frame installed on the casing, thereby opening and closing the airflow passage of the second outer conduit, changing the flow distribution between the first outer conduit and the second outer conduit, and thus switching the engine operating mode. The mode switching valve is applied to a wide-range adaptive cycle engine and adopts an "upwind" placement direction that is different from that of traditional adaptive cycle engines. In order to reduce the aerodynamic drag and instability risk caused by the "upwind" placement, an innovative grid drag reduction design scheme is adopted. The mechanism has a reasonable design, reliable movement, and good airtightness.

Embodiments of the present application provide a wind speed estimation method, device and aircraft. In the wind speed estimation method, flight data of the aircraft is obtained, and then a horizontal disturbance acceleration of the aircraft in a navigation coordinate system is obtained according to a vertical acceleration, a horizontal acceleration and an attitude angle of the aircraft in the navigation coordinate system in the flight data. Further, an air resistance of the aircraft in the horizontal direction is obtained according to a mass of the aircraft and the horizontal disturbance acceleration of the aircraft in the navigation coordinate system. Finally, the wind speed of the flight environment of the aircraft is obtained according to the air resistance and a speed of the aircraft relative to the navigation coordinate system, so that the wind speed of the flight environment of the aircraft can be estimated, the accuracy of the wind speed estimation is improved, and in the flight adaptation to different climate environments, only a few key parameters need to be adapted, so that the engineering practicability of the model is greatly improved.