酰化反应罐搅拌器的改造

针对河北冀衡(集团)药业有公司酰化反应罐所采用的框式+斜桨式搅拌器存在着设计较笨拙、液体间难以快速融合、反应速度较慢、收率相对较低、能耗较高等问题,将其改造成双层三窄叶旋桨式搅拌器。该搅拌器克服了原搅拌器的缺点,使反应时间由原来的约12 h缩短至约10 h,强化了固液之间的传质过程,提高了产品收率。

Measuring Propeller Blade Width Using Binocular Stereo Vision

Propeller blade width measurement has been extensively studied in the past using direct and indirect methods, and it plays a great role in determining the quality of the finished products. It has surveyed that previous techniques are usually time-consuming and erroneous due to a large number of points to be processed in blade width measurement. This paper proposes a new method of measuring blade width using two images acquired from different viewpoints of the same blade. And a new feature points matching approach for propeller blade image is proposed in stereo vision measurement. Based on these, pixel coordinates of contour points of the blade in two images are extracted and converted to real world coordinates by image algorithm and binocular stereo machine vision theory. Then, from the real world coordinates, the blade width at any position can be determined by simple geometrical method.

Kill probability modeling of multi-purpose guided missile against gunship and its application

Aimed at current deficiencies of multi-purpose guided missile kill probability model against gunship, the concept of the important coefficient of vulnerability blade unit is proposed in this paper. Laser fuze actuation model and warhead condition kill probability model of rotor blades are established by Monte Carlo method and kinetics theory with new ideas. Based on limited data, armor thickness of gunship is estimated, and a complete multi-purpose guided missile kill probability mathematical model is established, which provides necessary mathematical tool for the accurate and objective analysis of multi-purpose guided missile kill probability against gunship. Based on the establishment of the model, sensitivity analysis and optimal design of the main factors of multi-purpose guided missile kill probability are conducted, and the results show that the single multi-purpose guided missile lethality performance can be improved significantly by sensitivity analysis and optimization.

套马绳套住“米-8”直升机

套马绳能套住直升飞机，这听起来像是天方夜谭，但的确是发生在一个特殊时期的特殊事件。1974年3月14日11时，一架前苏联米-8直升机在中苏边境地区的一个白色哨所上空慢悠悠地飞行。几分钟之后，这架米-8直升机突然顺着额尔齐斯河越入了中国境内，在中国国境线内100公里的一个叫黑龙沟的地方降落了下来。

Pressure field measurements on large-scale propeller blades using pressure-sensitive paint

Pressure-sensitive paint(PSP)is a global pressure measurement technique.Compared with pressure transducers,PSP has significant advantages such as high spatial resolution and a lack of contact when applied to fast-rotating blades.However,due to the limitations of other pressure measurement techniques,the validation of PSP measurements on fast-rotating blades is generally difficult.In this work,a comprehensive study including PSP measurement,force balance measurement,and simulation was conducted on a 1 m-diameter propeller at the China Aerodynamic Research and Development Center.First,our computational fluid dynamics(CFD)code was validated by comparing the calculated aerodynamic thrust with the results from force balance measurements.Then,the pressure distributions on the propeller blade obtained by PSP were carefully compared with the CFD results under different working conditions.The results of PSP measurements,force balance measurements,and CFD showed good agreement,and the PSP measurement errors were estimated to be less than 5% of the dynamic pressure at the blade tip.Finally,the variations in pressure distribution under different rotating speeds and free-stream velocities were discussed.

Unsteady Flow at Low Flow-rate Region in a Semi-open Propeller Fan (Velocity Fluctuation outside of Blade Tip)

In order to clarify the unsteady flow fields at low flow-rate region with positive gradient on pressure-flow-rate curve,the experimental investigation was carried out at rotor inlet and outside of rotor blade tip without casing in a semi-opened propeller fan using a hot-wire anemometer.A single I-type hot-wire probe was used,and the data obtained were processed by the use of phase-locked averaging,ensemble averaging and FFT analyzing.The flow fields at rotor inlet and outside of rotor blade tip were discussed mainly using the results from distributions of velocity fluctuations and power spectrum density.It was found from these results that there are the two types of different periodical fluctuations and both of those frequencies were not the same of rotor rotating frequency(RRF;15Hz).One was observed at relatively high flow-rate region at relatively downstream area in measurement and its frequency was approximately 7Hz(47% of RRF).The other was observed at relatively low flow-rate region at relatively upstream area in measurement and its frequency was approximately 10Hz(67% of RRF)".As the velocity fluctuations with the flow fields are rapidly increased by the former fluctuation,it is thought that its fluctuation is the trigger of blade stall.

Numerical Simulation of the Tip Aerodynamics and Acoustics Test

The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical modelling for a reference helicopter rotor(without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FLOWer from DLR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake modelling. It solves the URANS equations with LEA(Linear Explicit Algebraic stress) k-ω model using the chimera overlapping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. L. and Watts M. E. during the Tip Aerodynamics and Acoustics Test(TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.