8 results about "Wetted area" patented technology

The invention discloses a hypersonic aircraft rough wall aerodynamic characteristic prediction method and device and a medium, and relates to the field of aircraft aerodynamic characteristic prediction.The method comprises the steps that the roughness height used for describing the roughness shape and the corrected surface infiltration area ratio are obtained; based on the wall temperature ratio, the compressible correction factor and the zoom coefficient, establishing a hypersonic rough wall RANS model; based on the hypersonic flight vehicle model with the smooth surface, the rough height and the corrected surface infiltration area ratio, in combination with the hypersonic rough wall RANS model, by means of a computational fluid dynamics method, streaming flow field simulation of the hypersonic flight vehicle to be predicted with the rough surface is carried out, and simulation data is obtained; and performing data post-processing on the simulation data to obtain the resistance and the heat flow of the to-be-predicted hypersonic aircraft with the rough surface. According to the method, the rough wall resistance and the heat flow of the hypersonic aircraft can be accurately predicted.

The application provides a boat wetting method, a wetted evaporation boat and use, and a boat wetting device. The boat wetting method comprises the following steps: S1, fixing an evaporation boat to be wetted on the surface of a porous placing plate; S2, vacuumizing; S3, heating a solid aluminum to obtain aluminum liquid; S4, immersing the evaporation boat to be wetted fixed on the surface of the porous placing plate in the aluminum liquid in a vacuum environment after vacuumizing to perform boat wetting treatment; and S5, taking out the evaporation boat after S4 is completed to obtain a wetted evaporation boat. S2 and S3 have no sequence. The boat wetting method provided by the application simplifies the boat wetting procedure, improves the boat wetting efficiency, reduces the cost, improves the wetting area and form of the evaporation boat surface, the surface structure of the wetted evaporation boat is compact, and the service life of the evaporation boat is improved.

The application discloses a hypersonic vehicle rough wall aerodynamic characteristic prediction method and device, and a medium, relates to the field of aerodynamic characteristic prediction of a vehicle, and comprises the following steps: acquiring roughness height and a corrected surface wet area ratio for describing roughness shape; establishing a hypersonic rough wall RANS model based on a wall temperature ratio, a compressible correction factor and a scaling coefficient; based on a surface smooth hypersonic vehicle model, the roughness height and the corrected surface wet area ratio, combining the hypersonic rough wall RANS model, simulating the flow field around the surface rough hypersonic vehicle to be predicted by using a computational fluid dynamics method, and obtaining simulation data; and performing data post-processing on the simulation data to obtain the drag and heat flow of the surface rough hypersonic vehicle to be predicted. The application realizes accurate prediction of the rough wall drag and heat flow of the hypersonic vehicle.

The invention is a kind of slide shoe type high speed boat, which adopts a certain position on the deep V type planing boat bottom to set several wedge-shaped slide shoes. At normal speed, the boat is in planing state, and has good seakeeping ability in high sea state; when the speed exceeds the critical point, the boat is in slide shoe planing state, the boat is supported by the water power of the front and rear slide shoes, the wetted area is greatly reduced, the resistance is reduced, and higher speed can be reached. Under similar power, the speed is greatly improved, and the energy efficiency ratio is high. The slide shoe has small volume, simple structure, and is convenient to combine with the boat body, and has good economy and applicability. The invention combines the good seakeeping ability of V type boat and the high speed of racing boat, changes the low speed and poor seakeeping ability of the current practical planing boat, and provides a boat type suitable for high sea state for military police and other special industries.

The invention provides a seaplane take-off and landing process dynamics calculation method and system suitable for high sea conditions, and the method comprises the steps: obtaining the hydrodynamic test data of a ship-shaped fuselage at the bottom of a seaplane in real time, and building a body coordinate system and a ground coordinate system; then establishing a height compensation model and an attitude compensation model based on the wave height to obtain a vertical distance and a pitch angle after wave influence correction, and calculating the infiltration area after wave influence at the current moment by adopting a specific calculation method; and finally, introducing the infiltration area influenced by waves on the basis of a total motion equation consisting of a centroid kinetic equation, a centroid kinematical equation, a rotation kinetic equation and a rotation kinematical equation, so as to establish an improved centroid kinetic equation, an improved centroid kinematical equation, an improved rotation kinetic equation and an improved rotation kinematical equation. Therefore, the real-time dynamic analysis of the take-off and landing process of the seaplane under the high sea condition is realized, and the method has remarkable rapidity, real-time performance and accuracy.

The present invention discloses a method for analyzing the pitching moment of a supercavitating projectile moving in water, comprising the following steps: obtaining the velocity, motion posture, force on the projectile, and wetting conditions of the supercavitating projectile; interpolating the pitching moment coefficients of the projectile in water and water vapor based on the motion parameters; calculating the pitching moment of the projectile generated by the gas in the cavitation cavity based on the motion parameters and the pitching moment coefficients; calculating the pitching moment of the projectile generated by the water based on the motion parameters and the pitching moment coefficients; obtaining the tail-slap force of the supercavitating projectile when it is tail-slapping, and calculating the pitching moment generated by the tail-slap force; and calculating the total pitching moment of the supercavitating projectile based on the pitching moment generated by the gas, the pitching moment generated by the water, and the pitching moment generated by the tail-slap force. The present invention proposes a method for accurately calculating the wetted length and wetted area of ​​the supercavitating projectile's tail-slap, which can accurately and conveniently solve the total pitching moment of a supercavitating projectile moving in water, thereby reducing research costs.

The invention provides an infiltration area calculation method and system for seaplane stability analysis, and the method comprises the steps: firstly building a body coordinate system and a ground coordinate system, building a seaplane model through modeling software, obtaining a pitch angle, a roll angle and a yaw angle of the seaplane model at a certain moment, and constructing a coordinate transformation matrix; then, a specific calculation method is adopted to calculate vertical sub-coordinates of vector coordinates of each triangular surface element under a ground coordinate system, a specific judgment method is adopted to judge the triangular surface elements soaked in water, and then the total soaking area of the seaplane model is calculated; and finally, based on the total infiltration area of the seaplane model at all moments, constructing a total infiltration area interpolation table by adopting a multi-dimensional interpolation algorithm, and further realizing stability analysis of the seaplane at different moments. The position and attitude change of the seaplane relative to the ground can be accurately described, and the calculation precision of the total infiltration area is effectively improved.

The invention discloses a dam access door detection operation method, and belongs to the technical field of water conservancy intelligent operation and maintenance. After the quick door is closed, the water flow channel is emptied and the access door is closed, the mooring type spherical unmanned aerial vehicle is lowered into the water flow channel through a dam crest vent hole, and cooperative detection is executed; dry shrinkage cracks and erosion damage are distinguished through texture anisotropy; risk enhancing factors are superimposed on leaks across the metal-rubber interface. And in the passing process, the lowering speed and the cable tension are dynamically adjusted according to the local curvature of the vent hole, and an accumulated curvature self-adaptive segmented lifting strategy is adopted in the recycling process. According to the invention, the problems of bent pore passage passing, leakage misjudgment, unclear maintenance priority and the like are solved, and safe, accurate and full-automatic detection is realized.