Acceleration Tangential

Tangential acceleration Acceleration of a fluid tangentially to a vane or impeller due to rotary motion. 

The plate speed is scaled-up from small (test) units to large (commercial) machines by maintaining the tangential acceleration. From this results the scale-up formula... 

Centripetal Acceleration. Centripetal acceleration, /r or CO r, where is the tangential linear velocity (m/s), rthe radius (m), and CO the angular velocity (rad/s), is, like any other linear acceleration, measured in SI units m/s. Centripetal force, equal to mass times centripetal acceleration, is, like any force in SI, measured in newtons. 

It is often convenient to use some other coordinate system besides the Cartesian system. In the normal/tangential system (Figure 2-10), the point of reference is not fixed in space but is located on the particle and moves as the particle moves. There is no position vector and the velocity and acceleration vectors are written in terms of... 

A widely used type of dust-collection equipment is the cyclone separator. A cyclone is essentially a settling chamber in which gravitational acceleration is replaced by centrifugal acceleration. Dust-laden air or gas enters a cylindrical or conical chamber tangentially at one or more points and leaves through a central opening. The dust particles, by virtue of their inertia, tend to move toward the outside separator wall from where they are... 

One approximation considers the time it takes for the particle to travel from the entrance point, r , to the wall, rw = D/2, relative to the residence time of the fluid in the cyclone. By neglecting the acceleration term and the fluid radial velocity and assuming that the velocity of the fluid at the entrance is the same as the tangential velocity at the wall (V = Vew), Eq. (12-42) can be integrated to give the time required for the particle to travel from its initial position (r ) to the wall (Dj2). If this time is equal to or less than the residence time of the fluid in the cyclone, that particle will be trapped. The result gives the size of the smallest particle that will be trapped completely (in principle) ... 

In the spiral or tangential cyclone inlet duct, the particles are accelerated to a velocity which is related to the inlet gas velocity Ue. Neglecting as a first approximation the slip between solids and gas, the kinetic energy of the solids which is transported per unit time into the cyclone is approximately given by... 

In internal mixing atomization (for example centrifugal-pneumatic atomization), 159] the liquid metal and gas enter the swirl jet atomizer tangentially under pressure (Fig. 2.13)J159] The two fluids rotate, form a mixture, and accelerate in the confuser. Due to the strong centrifugal force, the liquid metal forms a film at the nozzle exit even without the presence of the gas. With the applied gas, the liquid film is atomized into a fine dispersion of droplets outside the nozzle. 

The working principle of hollow cone nozzles is that the liquid throughput is subjected to rotation by a tangential inlet and is then further accelerated in the conical housing toward the orifice (see the sketch in Figure 19). A liquid film with a thickness d is thereby produced, which spreads to a hollow cone sheet and disintegrates into droplets at the discharge from the orifice. 

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