Vortex-mechanical

Vortex-Electrostatic Just like the chemical method, this new method is not usable when high degrees of force are called for. Vortex-Mechanical This method uses multiple mechanical cups or hooks, but similar to the magnetic method, it does not offer the high adhesion of the pneumatic method does. 

The main objective of the mechanical system is to define the robot s physical characteristics like shape, size, and drive motors. Figure 10 shows the CAD design and configuration ofthe climbing robot. There are three main parts drive motors, suction cups, and vortex mechanism. The robot has four drive motors, one for each wheel, a configuration that allows the robot to move from the floor to the wall thanks to the climbing force of the two frontal motors, aided by the thrust of the two back motors. The vortex motor starts any time the robot inclination reaches 45°, creating adhesion to the wall. 

Preparation is accompHshed by simple blending of the diluent into the hot base asphalt. This is generally accompHshed in tanks equipped with coils for air agitation or with a mechanical stirrer or a vortex mixer. Line blending in a batch circulation system or in a continuous fashion (40) is used where the volume produced justifies the extra faciUties. A continuous, line-blending system is appHcable to the manufacture of cutback asphalts and asphalt cements (Fig. 8). 

Flow measurements using nonintrusive or low mechanical ac tion principles are desired, such as magnetic, vortex-shedding, or Coriolis-type flowmeters. Orifice plates are easy to use and reliable but have a limited range and may not be suitable for streams which are not totally clean. Rotameters with glass tubes should not be used. 

A vertical cylindrical, and mechanical agitated pressure vessel, equipped with baffles to prevent vortex formation is the most widely used fermenter configuration. The baffles are typically one-tenth of the fermenter diameter in widtli, and are welded to supports tliat extend from the sidewall. A small space between the sidewall and the baffle enables cleaning. Internal heat transfer tube bundles can also be used as baffles. The vessels must withstand a 45 psig internal pressure and full vacuum of -14.7 psig, and comply with the ASME code. 

The cross-flow or tangential fan sets up an eccentric vortex within the fan runner, the air coming inwards through the blades on one side and leaving outwards through the blades on the other. It can, within mechanical limits, be made as long as necessary for the particular duty. 

In a forced vortex the angular velocity of the liquid is maintained constant by mechanical means, such as by an agitator rotating in the liquid or by rotation in the basket of a centrifuge. 

Thus, the energy per unit mass increases with radius r and is independent of depth In the absence of an agitator or mechanical means of rotation energy transfer will take place to equalise j/ between all elements of fluid. Thus the forced vortex tends to decay into a free vortex (where energy per unit mass is independent of radius). 

Vortex bursting mechanism proposed by Chomiak. (From Chomiak, J., Proc. Combust. Inst., 16, 1665, 1977 Ishizuka, S., Prog. Energy Combust. Sci., 28,477,2002.)... 

He considered that the rapid flame propagation could be achieved with the same mechanism as vortex breakdown. Figure 4.2.2 schematically shows his vortex bursting mechanism [4,5]. When a combustible mixture rotates, Ihe pressure on the axis of rotation becomes lower than the ambient pressure. The amount of pressure decrease is equal to max in Rankine s combined vor-fex, in which p denotes fhe unburned gas density and Vg denotes the maximum tangential velocity of the vortex. However, when combustion occurs, the pressure on the axis of rofafion increases in the burned gas owing to the decrease in the density, and becomes close to the ambient pressure. Thus, there appears a pressure jump AP across the flame on fhe axis of rotation. This pressure jump may cause a rapid movement of the hot burned gas. By considering the momentum flux conservation across the flame, fhe following expression for the burned gas speed was derived ... 

Maxworthy, T., Turbulent vortex rings. Journal of Fluids Mechanics, 64,227-239,1974. 

Ishizuka, S., Hamasaki, T., Koumura, K., and Hasegawa, R., Measurements of flame speeds in combustible vortex rings Validity of the back-pressure drive flame propagation mechanism, Proceedings of the Combustion Institute, 17, 727-734,1998. 

T. Poinsot, A. Trouve, D. Veynante, S. Candel, and E. Esposito. Vortex driven acoustically coupled combustion instabilities. Journal of Fluid Mechanics, 177 265-292, 1987. 

Samaniego, J.M. and Mantel, T, Fundamental mechanisms in premixed turbulent flame propagation via flame-vortex interactions Part I Experiment, Combust. Flame, 118, 537, 1999. 

Temporal sequence of OH-LIF measurements captures a localized extinction event in a turbulent nonpremixed CH4/H2/N2 jet flame (Re 20,000) as a vortex perturbs the reaction zone. The time between frames is 125 ps. The velocity field from PIV measurements is superimposed on the second frame and has the mean vertical velocity of 9m/s subtracted. (From Hult, J. et al.. Paper No. 26-2, in 10th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, 2000. With permission.)... 

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