Calculation and Analysis of Aerodynamic Characteristics of Supersonic Free Vortex Pneumatic Window
The fund project National Natural Science Foundation funded project 10082005, the National Defense Pre-Research Fund project funded project 200,13 propagation trajectory was calculated and described. 1 supersonic free vortex aerodynamic window flow field refractive index distribution supersonic free vortex aerodynamic window using an asymmetric nozzle to generate free vortex flow, the nozzle outlet section flow has a free vortex velocity distribution hereinafter referred to as this asymmetric nozzle is free Vortex nozzle. Pneumatic structure of supersonic free vortex aerodynamic window 2. In the supersonic free vortex aerodynamic window, in the non-viscous case, the inner and outer flow lines of the free vortex jet are swept by an arc of an angle of 9 at a constant radius of curvature, spanning The output aperture of the laser cavity. The pressure on the inside and outside of the nozzle outlet is equal to the laser cavity and the ambient pressure, respectively, thus avoiding the generation of a strong wave system, thus ensuring the quality of the output beam. Moreover, the outer side of the curved jet should be ensured to match the refractive index of the ambient atmosphere to improve the optical quality of the aerodynamic window. The ideal free vortex streamline radius and density relationship is 2 where 7 Qiu 0 is the density and reference constant of the working gas specific heat ratio critical state. Other flow parameter distributions in the radial direction at the nozzle outlet are also available. The distribution of the optical refractive index along the radius of the radial direction along the exit of the free vortex lance is proportional to the pressure ratio, respectively. For example, a free vortex pneumatic window of =20 and =50. Here, the calculation of the optical refractive index distribution is obtained from the gas density distribution. 2 Supersonic Free Vortex Pneumatic Window Flow The laser beam is a curved jet that passes through the free vortex aerodynamic window and is hereinafter referred to as a free vortex jet. The extent to which the free vortex jet affects the light transmitted through the window channel is the primary criterion for evaluating the performance of the free vortex aerodynamic window. The optical properties of the flow field parameters of the free vortex aerodynamic window are calculated without viscosity. In the laser beam path, the optical path difference between the light rays at different centers of the optical axis and the central axis of the optical axis below the center of the optical window is different after passing through the free vortex pneumatic window. The optical quality of the free vortex aerodynamic window is now analyzed by analyzing the distribution of the optical path difference along the cross section of the aerodynamic window optical channel. Here, the optical path difference of the ideal free vortex aerodynamic window is calculated and analyzed, and the influence of the shear layer is not considered. When the light propagates in the refractive index medium, the optical path of the light 1 = for the single component gas, the refractive index and the density The relationship has been given by Equation 2. The refractive index of the mixed gas can also be defined by Equation 2, but the mixed gas, 38, and 1 constant ruler are determined by the following equations: 0 and 445, respectively. From the geometric relationship of 2, the optical path difference of the supersonic free vortex jet 4 is dimensionless in the direction of the flow axis, and the upper middle curve and the lower curve are the free vortex pneumatic window pressure ratio, respectively. From this, it can be seen that for air = 1.4, the distribution of the optical path difference along the axial direction is symmetrical with respect to the center of the optical axis, and only the portion of 0 is drawn here. At the center, the curve slope is zero, and as the curve increases, the optical path difference and the slope of the optical path difference distribution curve also increase. The transmission at the center of the free vortex aerodynamic window is the density of the mixed gas, and the outside is the first component gas coordinate system. The axis points to the downstream of the flow, and the 7 axis coincides with the optical axis of the pneumatic window, and the origin coincides with the free vortex center. It is possible to use 4. The difference between the optical path at the sum of the optical axis and the optical path at the center of the optical axis, that is, the influence of the light is small, and the closer to the edge of the pneumatic window, the greater the influence of the jet on the light. From this analysis, the distribution of the optical path difference of the free vortex jet along the flow direction is very similar to that of the optical concave cylindrical lens, so the free vortex aerodynamic window produces a lens-like effect on the transmitted beam, so this pneumatic window can be used as a pneumatic lens. the study. On the other hand, the optical path difference increases slightly as the free vortex pneumatic window seal pressure ratio increases. 3 Optical characteristics analysis of supersonic free vortex aerodynamic window Based on the calculation results of optical path difference 4., the numerical simulation of the propagation trajectory of light in the free vortex flow field can be carried out. When calculating the optical trajectory of the free vortex jet, the free vortex jet can be divided into a sufficient number of aliquots in the radial direction. The width of each aliquot is 1 when 17 is small enough, and the radius can be considered to be the ruler, +6 , the jet density is uniform, the refractive index is uniform, and its refractive index is ft. + 2. Similarly, the radius of the jet between the ruler and the ruler is 1 ft. Refraction only occurs at the interface of the ruler + 4. After establishing the ray deflection relationship of the adjacent two-stage flow, the ray propagation path of the entire free vortex flow field can be solved by the recursive method. It can be seen from the optical refraction formula that when the angle of the person refracted at the radius of 7 is known, the angle of refraction and the angle of the person whose radius is +1 ft. By analogy, when the light passes through the aerodynamic window from the optical cavity parallel to the optical axis, if the coordinates of the human spot on the inside of the jet are known, the coordinates and optical path of the ray at any radius can be determined. This will solve the trajectory of the light. The light trajectory of the free vortex aerodynamic window with a pressure ratio of 5=50 and servant is a parallel light transmission pressure ratio of 20 and 50, respectively. From the optical track mirror, there is a fixed divergence effect on the light. For light rays near the optical axis, the divergence is small. a pressure ratio p, 4 Conclusion The distribution of the optical path difference of the free vortex jet along the flow direction is very similar to that of a thin optical concave cylindrical mirror, so the free vortex aerodynamic window produces a lens-like effect on the transmitted beam, which acts as a negative Thin cylindrical lens with a fixed divergence effect on light. The optical refractive index profile of the supersonic free vortex aerodynamic window is responsible for the generation of a pneumatic lens effect. For light rays near the optical axis, the divergence is small. Moreover, the optical path difference increases slightly as the free vortex pneumatic window seal pressure ratio increases by one. The above results were obtained under ideal conditions without considering the influence of the shear layer. In fact, since the influence of the shear layer increases as the jet distance increases, the distortion of the laser beam caused by the downstream jet is larger than that of the upstream. Therefore, the laser beam is preferably outputted near the optical axis of the free vortex pneumatic window to reduce optical distortion caused by the free vortex jet. Reduce the normalized range deviation for different seasons. reference! 7 The influence of ambient temperature change on the range of a bottom row 234 Ding Shengsheng, Luo Rong, Chen Shaosong and so on. Bottom combustion, several parameters of resistance properties affect the study. Journal of Ballistics, 1996, Vol. 47983. Guo Rust Fu. Research on the standardization method of the bottom exhaust flare range. China National Defense Science and Technology Report, 109900120, 21. Metal Hole Saw,Carbide Big Hole Saw Bit,Metal Hole Saw Bit,Hole Saw Cutter Bit Danyang Yongshun Tools Co.,Ltd , https://www.china-drill-bit.com