4results about How to "Has engineering practical value" patented technology

The invention belongs to the technical field of high-speed wind tunnel tests, and discloses a high-speed jet flow wind tunnel large-scale model velocity pressure simulation test method, which comprises the following steps: installing a model at an initial state position; calculating the total pressure P0 of the wind tunnel; the injection pressure P0p is calculated; starting a high-speed free jet wind tunnel; transforming the model to a second state; performing flow field parameter adjustment according to the model state, and performing static pressure matching fine adjustment; continuing to transform the model state until all data are collected; and closing the high-speed free jet wind tunnel. According to the high-speed jet flow wind tunnel large-scale model velocity pressure simulation test method, under the condition that the Mach number M is determined, the wind tunnel total pressure P0 and the injection pressure P0P are selected, accurate simulation of the Mach number M and the velocity pressure is achieved, and the method has engineering practical value.

The application provides a low-profile duplex filter antenna and belongs to the technical field of wireless energy transmission.The low-profile duplex filter antenna comprises an upper metal floor, a dielectric substrate, a lower metal floor, a cavity column, a perturbation via and a suppression via; the lower metal floor is arranged on the lower surface of the lower dielectric substrate; the upper metal floor is arranged on the upper surface of the dielectric substrate; the cavity column penetrates through the upper metal floor, the dielectric substrate and the lower metal floor and surrounds a substrate integrated waveguide cavity; the perturbation via and the suppression via penetrate through the upper metal floor, the dielectric substrate and the lower metal floor; a cross-shaped groove is etched in the center of the upper metal floor; two complementary split ring resonator grooves with different diameters are etched at the connection between the circular cavity and the two side rectangular cavities of the upper metal floor; two feed lines are led out from the two ends of the upper metal floor. The antenna has the characteristics of low profile, is easy to integrate, and simultaneously reduces the manufacturing cost of the antenna and facilitates processing and manufacturing.

The present application belongs to the technical field of high-speed wind tunnel test, and discloses a high-speed transverse gas jet test device and test method. The test device comprises a test model located in the test section of a high-speed wind tunnel, the inner cavity of the test model is sequentially fixed with a balance and a support rod from front to back, the rear section of the balance is sleeved with a heat insulation sleeve, a gas generator is installed on the support rod, and the rear section of the support rod is connected with a high-speed wind tunnel support mechanism. The test device further comprises a fuel storage tank and an air storage tank which are placed outside the high-speed wind tunnel and provide fuel and air for the gas generator, and an ignition controller of the gas generator. The test method establishes a safety interlocking test timing, ensures the reliability and safety of the high-speed transverse gas jet test, provides a stable time of the hot jet of 10s order, a stable chamber pressure, non-toxic and harmless gas, can simulate the specific impulse, temperature, specific heat ratio and secondary combustion effect of the real high-speed aircraft jet gas, and has engineering practical value.

This invention belongs to the field of hypersonic aerodynamics and discloses a method for predicting hypersonic boundary layer transition based on the numerical solution of the frequency domain Navier-Stokes equations. This method, through the assumption of small perturbations, linearly decomposes the hypersonic flow field into a steady flow field and a perturbed flow field. It eliminates the time differential terms in the time-domain Navier-Stokes equations using complex decomposition, transforming the time-domain Navier-Stokes equations into linear algebraic equations in complex space, thereby simplifying the solution and analysis of the time-domain Navier-Stokes equations. Specifically, it includes three stages: preprocessing, solver, and post-processing. The iterative solution of the frequency-domain Navier-Stokes equations in the solver is the core, including spatial discretization of the frequency-domain Navier-Stokes equations, iterative progression, implementation of boundary conditions, parallel data exchange, convergence judgment, and result output. The hypersonic boundary layer transition prediction method based on the numerical solution of the frequency-domain Navier-Stokes equations of this invention can balance computational efficiency and accuracy, and has practical engineering value.