81 results about "Thrust coefficient" patented technology

The invention provides a differential adjustable unilateral expansion nozzle. In the invention, a nozzle throat area is bilaterally adjustable and differential adjustment can be carried out to ensure that an engine flow variation requirement is satisfied in a whole flight envelope; an nozzle exit area is adjustable to ensure that a gas ideal complete expansion requirement can be satisfied in a certain flight Mach number range; and the upper web of a nozzle is divided into an adjustable upper web and a fixed upper web between which a certain gap exists and the after body of an aircraft can be directly utilized by the fixed upper web so that that the operating force of a movement mechanism can be reduced. A boundary layer discharged from a front fuselage can be injected into the fixed upperweb through the gap under the flight conditions of transonic speed and low supersonic speed; and therefore, the wall static pressure of the fixed upper web is increased, the thrust loss caused by airflow overexpansion is decreased, meanwhile, the pitching moment of the aircraft is reduced and the nozzle is ensured to always achieve a higher thrust coefficient in the broad flight envelope, in addition, the cooling of the fixed upper web can be strengthened and the thermal load and the infrared signal characteristic of the nozzle are reduced.

A control method and a control apparatus of a wind power generator set are provided, in which a wind speed at a location of the wind power generator set is acquired, turbulence intensity is calculated according to the wind speed, and a wind speed distribution range corresponding to the turbulence intensity is determined; a thrust variation amplitude of the thrust in the wind speed distribution range is determined based on a relationship among the thrust suffered by a wind wheel of the wind power generator set, a thrust coefficient and the wind speed; and a maximum rotating speed and a maximum torque of the wind wheel in the wind speed distribution range are adjusted according to the thrust variation amplitude. The maximum rotating speed and the maximum torque makes a fatigue load of the wind power generator set in the wind speed distribution range meet a preset standard.

The invention discloses a loading system for a test platform of a wind generating set. The loading system comprises a motor, wherein the motor is connected to a reduction box; an output shaft of the reduction box is connected to an input shaft of the wind generating set through a universal coupler; a load simulating part is arranged on a shaft position of the universal coupler; an electromagnet generating device is additionally arranged on at least one of up and down peripheries and left and right sides of the load simulating part; and the electromagnet generating device and the motor are respectively connected to a control system. According to a congruent relationship between a rotating speed of the generating set and an air speed and a thrust coefficient of the generating set, the control system of the test platform is utilized to solve a thrust value generated by the generating set and calculate a current value for generating the corresponding thrust and gravity by an electromagnetsystem, and the electromagnet system is utilized to load the load simulating part and simulate the thrust, gravity, bending moment parameter, and the like, of a fan under a practical wind condition.

The invention discloses a wind power plant optimal control method based on a wake flow effect. Based on a Jensen wake flow model, wake flow air speed influence factors are analyzed, the wind turbine thrust coefficient is finally determined, and power output of a wind turbine can be optimized; and in particular, according to the wind turbine wake flow characteristic, a wind turbine wake flow speed stacking model is built, a numerical fitting method is then used for conducting numerical fitting on the wind turbine thrust coefficient and the wind-power utilization coefficient, fitting results are joined with the Jensen wake flow model, a wind turbine output power model is refined, and an optimal model of the wind turbine output power model is obtained. By means of the wind power plant optimal control method, a visualization method can be used for detecting change conditions of the wind power plant total output power at different wind speeds after a control optimization algorithm is added, and the effectiveness of the control algorithm is indicated compared with the total output power in the natural state.

The invention discloses an intelligent optimization design method for a low-wind-speed wind turbine generator wind wheel, which comprises the following steps: selecting blade aerodynamic configurationparameters as optimization variables, calculating a blade power coefficient and a thrust coefficient according to variable values, and constraining Cpmax and Ctr; selecting the structural layer design parameters as optimization variables, calculating the mass center, the rigidity distribution and the inertia structural performance of each section of the blade, and forming a blade model by combining the aerodynamic configuration data; Adding the blade model into the complete machine model, and calculating the annual generating capacity of the complete machine; calculating and counting the dynamic load to obtain the maximum limit load of the blade root, the fatigue load and the blade clearance, and constraining the blade clearance; and finally, selecting a reasonable range of each optimization variable, and searching a blade design optimal solution by taking the maximum annual generating capacity and the minimum blade root load as optimization objectives. The optimized blade can ensurethe structural strength, the annual generating capacity is increased, the blade root load is reduced, the blade efficiency is improved, the cost is reduced, and the competitiveness is higher.

The invention provides a method for simulating an inland river pushing fleet, which includes: determining the coordinate origin of the fleet coordinate system and the center of gravity of the fleet according to the fleet parameters; combining the coordinate origin and the center of gravity into one point to obtain the simplified four-freedom of the fleet degree motion equation; calculate the inertial force and viscous hydrodynamic force of the ship according to the length of the pusher and barge, the width of the pusher and barge, the draft of the barge and pusher, and the square coefficient of the ship; calculate the fleet according to the inertial hydrodynamic force and viscous hydrodynamic force of the ship The additional mass of the propeller; calculate the thrust of the propeller and the rudder force of the ship according to the rotational speed, diameter, advance speed, wake coefficient and thrust coefficient of the ducted propeller; substitute the additional mass, propeller thrust and rudder force into Runge Kuta to calculate the ship The acceleration and speed of the fleet; the simulator simulates the navigation of the real inland river pushing fleet according to the acceleration and speed of the fleet. The invention regards the pusher boat and the barge as one ship, fully considers the influence factors of the inland river environment, and realizes the simulation of the inland river pusher fleet.

The invention relates to the technical field of linear motors and discloses a coreless linear motor of an embedded I-shaped coil. The coreless linear motor comprises a U-shaped stator and an I-shaped mover. The I-shaped mover comprises an I-shaped coil and a mover installation plate arranged at one end of the I-shaped coil, and the other end of the I-shaped coils is arranged in the U-shaped stator. The I-shaped coil is composed of three phase coil windings, namely, a U-direction coil winding, a V-direction coil winding and a W-direction coil winding, the coil windings are mutually embedded with one another and are uniformly braided, four groups of coil windings pass through a gap in each group of coil windings, and the gaps in the coil windings are the same. The coil in the invention is of an I shape which is formed by mutually embedding and uniformly braiding the coil windings. Compared with a traditional coreless linear motor, the coreless linear motor provided by the invention has a higher space utilization rate, a larger thrust coefficient, higher structure rigidity and better thrust uniformity.

The invention provides a wind power plant output power optimization method and device and a realization device. The method comprises the following steps of: obtaining a wind speed, a wind direction and arrangement information of wind turbine generators in a wind power plant; determining an input wind speed of each wind turbine generator according to the wind speed, the wind direction, the arrangement information and a pre-established corresponding relationship among input wind speeds, pitch angles and thrust coefficients of the wind turbine generators; determining total output power of the wind power plant according to the corresponding relationship among the input wind speeds, pitch angles and thrust coefficients of the wind turbine generators; and determining a pitch angle of each wind turbine generator corresponding to the maximum value of the total output power by taking the pitch angle or thrust coefficient of each wind turbine generator as an adjustment parameter and taking the total output power as a target function, and sending the pitch angle to a corresponding wind turbine generator. According to the wind power plant output power optimization method and device and the realization device, the maximization of output power of wind power plants can be realized, the wind energy loss caused by wake flow influences between the wind power plants is decreased and the total generation capacities of the wind power plants are improved.

The invention relates to a combined flow control method and structure for improving an SERN for a TBCC. The combined flow control method and the combined flow control structure are characterized in that a passive cavity structure is added on an upper expansion ramp of the SERN, and a convergent secondary flow nozzle is formed in a lower inclined plate of the SERN; and the oblique shock wave position is controlled in an overexpansion state through adopting the simple passive cavity structure and a secondary flow jet device under the precondition that the required control energy is not obviously added, the pressure distribution of a nozzle on a single ramp is improved, the thrust coefficient of the SERN in the overexpansion state is improved, and the thrust performance of an air-breathing hypersonic velocity propelling system in the transonic velocity stage is improved.

The invention discloses a hydrodynamic performance testing method for a biomimetic flexible flapping wing mechanism, and belongs to the field of biomimetic testing. The biomimetic flexible flapping wing adopts a naca airfoil profile, and the material of the biomimetic flexible flapping wing is silica gel. The hydrodynamic performance testing method for the biomimetic flexible flapping wing mechanism adopts a hydrodynamic performance testing device which comprises a biomimetic flexible flapping wing motion propelling platform, a biomimetic flexible flapping wing and a PIV (Particle Image Velocimetry) testing system. By use of the hydrodynamic performance testing method for the biomimetic flexible flapping wing mechanism, key parameters, including the energy conversion efficiency, the torquecoefficient, the thrust coefficient and the like, of the biomimetic flexible flapping wing for measuring the performance of the biomimetic flexible flapping wing can be tested, a reference can be provided for the design of a biomimetic flexible flapping wing engineering prototype, and an experiment basis can be provided for the CFD (Computational Fluid Dynamics) numerical simulation and the theoretical research of the hydrodynamic performance of the biomimetic flexible flapping wing.

The invention relates to a multifunctional bionic hydrodynamic test platform which comprises a circulating water tank, a carrying platform, an optical platform, an impeller and an autonomous cruise prototype mounting device. The hydrodynamic tests capable of being carried out comprise various aircraft group swimming hydrodynamic tests, hydrodynamic tests of starting-uniform motion-deceleration stop modes of autonomous cruise prototypes, and hydrodynamic tests of naca airfoils. Through the test platform, the energy conversion efficiency, the main shaft load, the torque coefficient and the thrust coefficient can be measured, vortex field analysis and track extraction of key positions of an experimental model can be carried out at the same time, and by means of the test platform, a mechanical hydrodynamic test of an airfoil can be completed; experimental verification can be provided for CFD numerical simulation and theoretical research of the hydrodynamic performance of the underwater vehicle, and reference and guidance can be provided for design of the underwater vehicle.

The invention discloses a wake flow calculation method and device based on a bivariate Gaussian function and a storage medium, and belongs to the technical field of wind turbine generator wake flow calculation. The method comprises the following steps: according to field measurement data, obtaining incoming flow speed, spanwise turbulence intensity and vertical turbulence intensity in front of the wind turbine generator, and hub height, impeller diameter and thrust coefficient of the wind turbine generator; calculating to obtain a wake flow expansion coefficient; calculating an initial wake flow radius according to the wake flow expansion coefficient; according to the obtained wake flow expansion coefficient and the initial wake flow radius, calculating the spanwise and vertical wake flow radiuses; and according to the obtained wake flow radiuses in the spanwise direction and the vertical direction, obtaining the speed loss of the wake flow area. The hypothesis adopted by the method is closer to the actual development characteristic than the hypothesis of a traditional wake flow calculation method, so that the wake flow calculation method provided by the invention can better predict the speed of the wake flow center point, and the spanwise and normal wake flow speed evolution laws can be given.

The invention discloses a spatial variation-based dynamic double-Gaussian wind turbine wake flow speed calculation method. The method comprises the following steps: determining a runner diameter and a thrust coefficient of a wind turbine, and calculating an initial wake flow radius; collecting an incoming flow wind speed of the wind turbine, determining an initial wake flow expansion coefficient, an exponent sign, and a radial distance between a wake flow wind speed minimum value point and a hub center line , and calculating an effective runner diameter; dividing a wake flow area of the wind turbine into a wake flow area close to a runner, a near wake flow area, and a far wake flow area, determining a corresponding wake flow expansion coefficient and an exponent sign, and calculating wake flow radius distribution in combination with the initial wake flow radius; establishing a wake flow unilateral Gaussian profile distribution function on the two sides of the center line of the hub, and calculating a wake flow double Gaussian distribution profile; calculating maximum normalized speed attenuation by combining an average momentum flow equation flowing through the runner and a thrust calculation formula, further calculating speed attenuation of the wake flow area, and determining speed distribution of the wake flow area. According to the invention, the accuracy of calculating wake flow wind speed distribution in a full wake flow area is improved.

An axial symmetry plug type spray pipe having an afterburning function is characterized by comprising a spray pipe outer wall barrel, a spray pipe outer wall convergent section, a spray pipe outer wall convergent section, a spray pipe inner wall barrel, an oil spraying ring, an ignition device, a flame stabilizer, a spray pipe inner wall convergent section, a spray pipe inner wall expansion section and a plug body. The spray pipe outer wall barrel, the spray pipe outer wall convergent section and the spray pipe outer wall convergent section are connected with each other through flange mounting edges to form an annular outer wall channel wall; and the spray pipe inner wall barrel, the spray pipe inner wall convergent section and the spray pipe inner wall expansion section are connected through flange mounting edges to form an annular inner wall channel wall. The oil spraying ring, the ignition device and the flame stabilizer are positioned in an annular channel I defined by the outer wall channel wall and the inner wall channel wall. The axial symmetry plug type spray pipe has the advantages that an engine has a good thrust coefficient when at a high altitude state and has a certain attenuation effect on radar waves.

The embodiment of the application provides a method, device and system for determining a wake flow field of a wind generating set. The method for determining the wake flow field of the wind generating sets comprises the following steps: acquiring the current equivalent wind speed of the windward side of an impeller of each wind generating set in a wind power plant; determining the current thrust of each wind generating set according to the power coefficient, the thrust coefficient and the equivalent wind speed of each wind generating set under the current equivalent wind speed; determining a current candidate wake flow field of each wind generating set according to the current thrust of each wind generating set; determining whether the deviation between the current candidate wake flow field and the last candidate wake flow field is smaller than a preset value or not; if yes, using the current candidate wake flow field as the wake flow field, and otherwise, continuously determining the next candidate wake flow field of each wind generating set. According to the embodiment of the application, the calculation accuracy of the wake flow field of the wind generating set can be improved.

The invention provides a shafting thrust structure of a vertical shaft diesel engine for an outboard engine, including a shafting, a load-bearing structure, and an annular thrust; the shafting can be a power output crankshaft, a camshaft, and a balance shaft, which is different from conventional The internal combustion engine is arranged horizontally, and the diesel engine for the outboard engine adopts the vertical arrangement of the shafting, and the shafting thrust is the key technology for the power output of the vertical axis; Under the joint action of lubricating oil, a sliding oil film bearing is formed to meet the thrust requirements of high-load diesel engines. The shafting thrust structure of the vertical shaft diesel engine described in the present invention is applied to the shafting of an internal combustion engine with a higher strengthening coefficient, and solves the problem that the excessive axial movement of the vertical shafting shaft during operation causes the piston movement trajectory to exceed the tolerance requirements, thereby causing parts Damage problem. The thrust structure of the shaft system of the vertical shaft diesel engine in the present invention has the advantages of high compactness, high resistance to explosion pressure, high reliability and the like.

The invention discloses a method for improving the prediction precision of a Gaussian wake flow model on a wind turbine wake flow field. The method comprises the following steps: step 1) obtaining a thrust coefficient of a wind turbine; 2) obtaining a proportionality coefficient; 3) obtaining an initial standard deviation coefficient; 4) acquiring standard deviation; step 5) combining a Gaussian wake flow model to obtain the speed loss of a wake flow area; the invention aims to improve the precision of the obtained initial standard deviation coefficient by improving the obtaining means of the initial standard deviation coefficient from the aspect of improving the universality of the initial standard deviation coefficient, and solves the problems that the universality of the initial standard deviation coefficient obtained by adopting a conventional method is insufficient, therefore, the technical problem that the Gaussian wake flow model has great influence on the prediction precision of the wake flow area speed in different environments is solved.

The invention discloses a performance data acquisition method and system for a wind machine. The method comprises the steps of according to parameter data of the complete wind machine, forming a basic performance curve database by integrating performance curves of a wind machine under different air densities, and acquiring a performance curve under actual air density according to the performance curves in the basic performance curve database. The performance curves in the basic performance curve database further include a power curve, a thrust coefficient curve and a power coefficient curve. The method further comprises the steps of acquiring a power curve under the actual air density according to the power curve in the basic performance curve database, and calculating the generating capacity of the wind machine in combination with the power curve through externally input wind energy data. According to the method and system, the technical problem of incapability of achieving quick response calculation and result output due to numerous dependency conditions of a conventional calculation method can be solved, so that a calculation process can be greatly simplified; and the method and system have the advantages of high calculation efficiency, high precision and data portability.

The invention provides a tidal current energy water turbine array optimization method based on a gridding sea area, and the method comprises the steps of firstly, determining the sea area arrangementrange and the average flow velocity of tidal current in an arrangement area, arranging the number of water turbines, and determining the performance coefficient of the water turbines; gridding the seaarea according to the parameters of the water turbine; determining the algorithm parameters, wherein the algorithm parameters comprise the number of cross generations, the variation rate and the iteration step number; generating an initial population; crossing the individuals in the population to generate filial generations, and adding the filial generations into the population; selecting a certain number of population individual variations to generate new individuals, and adding the new individuals into the population; solving the target values of all individuals in the population; secondly,judging whether the algorithm is finished or not, if not, returning to the step of population intersection, and if yes, selecting the individual with the maximum target value as an optimization result. The sea area to be arranged is dispersed, the influence of the water turbine on the reduction of the rear flow field flow velocity and the correlation between the thrust coefficient of the water turbine and the tidal current flow velocity are considered, the consumed calculation resources are few, and the reference can be provided for preliminary design of a tidal current energy power generation airport.

A method for generating predictions of rocket motor ballistic performance at specific firing temperatures and for generating data profiles for analysis. The method requires generally available specifications for the rocket motor to be tested and test data from one or more test firings at a known temperature. The method is implemented in software form and generates pressure and thrust versus time data at a selected temperature. The method generates a burnback profile with a correct final web that integrates to the correct final propellant weight as well as a throat area profile and thrust coefficient profile, for the test firing temperature and for the temperature to be predicted.