52results about How to "Increase the total pressure recovery coefficient" patented technology

The invention provides a low-external-resistance supersonic / hypersonic speed inlet. A two-dimensional bump is arranged at an inlet of the supersonic / hypersonic speed inlet, and partial air discharge seam / hole arrays are arranged at the inward concave positions of the windward side and the leeward side; and meanwhile, an air discharge cavity below the bump is divided into two sub-cavities, and electromagnets and a metal plate with a folded corner are adopted for achieving control over opening and closing of the two air discharge sub-cavities. By means of control over opening and closing of the two air discharge sub-cavities, the low-external-resistance supersonic / hypersonic speed inlet can adapt to shock wave intensity and incidence point position changes brought by inlet working mach number and attitude angle changes, the optimal control ability on boundary layer separation caused by shock wave / boundary layer disturbance of a lip cover is obtained, and the remarkable effects of widening the working range of the low-external-resistance supersonic / hypersonic speed inlet and increasing the total pressure recovery coefficient are achieved. Due to the high flowing control ability of the low-external-resistance supersonic / hypersonic speed inlet, the inlet is allowed to adopt the design of the horizontal lip cover, and therefore the external pneumatic resistance of an aircraft can be effectively reduced.

The invention discloses a method for designing a fixed-geometry two-dimensional mixed-compression type supersonic velocity air inlet channel. A basic structure of the adopted two-dimensional mixed-compression type air inlet channel comprises an outer pressing section, an inner pressing section, a throat section, an expanding section and a lip. The lip is of a sharp plate structure with a certain wedge angle. When the air inlet channel is designed, designed starting Mach number is improved appropriately, the lip shape is changed, and the starting mach number is effectively reduced to be lower than a requested value through a certain flow on the premise that the flow requirement of the air inlet channel is met. By means of the method, the requirement for starting performance can be met, contraction ratio of the air inlet channel can be increased in design, and accordingly high back pressure resisting capability and low outlet Mach number are obtained in a wide working range to facilitate efficiently combusted organizations in a combustion chamber. Furthermore, small total pressure loss in the working process of the air inlet channel can be achieved through the change of the lip shape. The method for designing the fixed-geometry two-dimensional mixed-compression type supersonic velocity air inlet channel has good actual application value.

The invention relates to a design method of a hypersonic velocity air inlet channel. The design method comprises the steps of creating a reference flow field profile based on a functional relation; optimally designing axial symmetric reference flow fields of the air inlet channel; and then obtaining a three-dimensional profile of the air inlet channel through a streamline tracking method. Comparedwith the prior art, the method has the advantage that the problem that the design of a traditional air inlet channel is performed by designing inner flow field condition firstly, and the total pressure recovery coefficients of the air inlet channel cannot reach the maximum value while the shock wave sealing of a port is realized, can be solved.

The invention discloses a plasma vortex generator-based inward-rotating air inlet component and a control method thereof. The assembly includes a machine body plane and an inward turning air inlet body, wherein one or more sets of arc spark discharge plasma vortex generators are arranged at a certain distance upstream along the compression surface below the machine body plane. This method uses the flow vortex formed by the interaction between the plasma jet and the free flow to promote the momentum exchange between the main flow and the low-energy flow in the boundary layer, enhance the ability of the boundary layer to resist the reverse pressure gradient, and reduce the shock wave / boundary layer induced by the downstream internal compression surface. The interference separation zone has a certain delay or inhibition effect, thereby effectively improving the performance of the intake port. Compared with the traditional method, the control method proposed by the present invention does not require additional air source, no flow loss, no additional resistance, and the control method is accurate and efficient, which has great advantages for the wide speed range and integrated design of the internal rotation air inlet. important promotion.

The invention provides a diverterless subsonic air inlet passage integrated with an aircraft. The diverterless subsonic air inlet passage comprises a lip cover on the basis of electromagnetic stealth and pneumatic consideration and a fully shielded inner pipeline. The shape of an air inlet passage opening surface and a fuselage are in integrated combination designs, and boundary layers at the fronts of inlets can be eliminated by pressure gradients formed by the lip cover and the surface of the fuselage. The lip cover is in sweepback designs in the overlooking and side-looking directions, and sweepback angles are consistent with preset stealth angles of the aircraft. The inner pipeline with an air inlet passage is provided with a selected fully shielded double-S bending type air inlet passage, and the cross sections of outlets of the air inlet passage cannot be seen from optional angles of air inlets. The diverterless subsonic air inlet passage has the advantages that specific bumps, which are protruded on the surfaces of existing fuselages, of conventional diverterless air inlet passages and boundary layer diverters on the existing fuselages can be omitted on the premise that requirements on total pressure recovery coefficients and flow field distortion indexes of the air inlet passage are met, and accordingly pneumatic resistance of the aircraft can be lowered; the radar stealth performance of the air inlet passage can be enhanced under the joint effect of the aircraft, the sweepback lip cover and the fully shielded inner pipeline.