Traffic Congestion Model in India by Shock Wave Theory

This manuscript is a series of traffic flow analysis in India and it describes traffic congestion model by using shockwave theory from fluid mechanism. This is unique study for emerging country India traffic flow analysis during more than one month in October 2020. In order to chaotic traffic flow analysis in India, author observes one moth traffic flow data from the traffic monitoring cameras in 26 locations in a city where it is one of major city Ahmedabad in Gujarat states of India. In terms of traffic congestion, it is sued occupancy parameter of traffic flow data which indicates road occupancy percentage by vehicles. By using shock wave theory, author defines two traffic congestion model which are “forwarding traffic congestion” model and “stacking traffic congestion” model. These models explain traffic congestion condition and it is able to provide hint for solving traffic congestion problem in India.

Preparation of Sub-Micron Bi Alloy Powers with the Ultrasonic Mixed Crushing

The powders of the BiInSn alloy were produced by the ultrasonic atomization and the ultrasonic mixed crushing using the different dispersants. In this study, the composition, microstructure, melting point, and size of these powders were observed. The viscosity of different solutions of the dispersants and the mechanical properties of the sintered bulk materials were also tested. From the data analysis and results, we found that the composition of the powders using the different methods was consistent with the as-cast state. In addition, the size of powder produced by ultrasonic mixed crushing was significantly smaller than that ultrasonic atomization. And during the ultrasonic crushing process, with the increase of the viscosity of the dispersant, the size of the final powder also decreased, and even submicron powder were produced. The product of submicron powder could effectively improve the density and mechanical properties of sintered materials. And the principles of ultrasonic atomization and ultrasonic mixed crushing were discussed. We found that the mechanism of ultrasonic mixed crushing to produce powder was the micro-shock-wave theory of ultrasonic cavitation. At the same time, these dispersants were effective in keeping the droplets separate from each other and preventing them from merging back into the larger droplets. The droplet was solidified into a powder by rapid cooling in the end.

One-dimensional capillary jumps

In flows where the ratio of inertia to gravity varies strongly, large variations in the fluid thickness appear and hydraulic jumps arise, as depicted by Rayleigh. We report a new family of hydraulic jumps, where the capillary effects dominate the gravitational acceleration. The Bond number – which measures the importance of gravitational body forces compared to surface tension – must be small in order to observe such objects using capillarity as a driving force. For water, the typical length should be smaller than 3 mm. Nevertheless, for such small scales, solid boundaries induce viscous stresses, which dominate inertia, and capillary jumps should not be described by the inertial shock wave theory that one would deduce from Bélanger or Rayleigh for hydraulic jumps. In order to get rid of viscous shears, we consider Plateau borders, which are the microchannels defined by the merging of three films inside liquid foams, and we show that capillary jumps propagate along these deformable conduits. We derive a simple model that predicts the velocity, geometry and shape of such fronts. A strong analogy with Rayleigh’s description is pointed out. In addition, we carried out experiments on a single Plateau border generated with soap films to observe and characterize these capillary jumps. Our theoretical predictions agree remarkably well with the experimental measurements.

Destruction Analysis of Broadside Multi-Cabin Protective Structure of Warship under Explosion Loading

Shock wave parameters of cabins for shipboard defensive structure are studied based on shock wave theory. The destroy of defensive structure can be estimated by impulse of shock wave. In the process of air shock wave propagating, isentropic suction wave is reflected from void cabin into defense structure. The solution of shock wave attenuation of void cabin can be reached by using isentropic line to replace the shock adiabatic of the reflected shock. It can be seen from the example that the multi-layers defense structure system of warship is very important to decrease the damage from explosive shock wave. The method can be used to predict the extent of damage of naval vessel.

A New Method to Estimate the Projection Angles of Fragments from a D Shape Configuration

The oblique shock wave theory is used to describe the process of detonation wave shocking on the metal surface. And after the transmission wave in metal transmitted to the free surface of metal, the velocity multiplication law of free surface is used to simplify the shock wave theory to estimate the velocity of particles in metal. Then the projection angle is obtained from the velocity direction to the normal of initial metal surface. In addition, the explosion experiments of a D shape configuration have been done to validate this method. And the results show that this method is in better agreement with experimental projection angles than traditional Taylor equation.

The Optimization Design for Protection Plate Structure of Honing Measuring Head

In order to improve the pneumatic gauging precision of honing process, according to the pneumatic gauging characteristic of honing machine, the mathematical model of air current state in measurement process is established with oblique shock wave theory. Through setting up different fillet on protection plate, the air flow state of measurement process could be improved. The change of gas velocity, temperature and pressure was analyzed for different protection plate structure by fluid simulation software, the validity of the theoretical analysis was verified, which can provide the theory basis for structure optimization of the honing head.