Oscillating motion

Noise Control Sound is a fluctuation of air pressure that can be detected by the human ear. Sound travels through any fluid (e.g., the air) as a compression/expansion wave. This wave travels radially outward in all directions from the sound source. The pressure wave induces an oscillating motion in the transmitting medium that is superimposed on any other net motion it may have. These waves are reflec ted, refracted, scattered, and absorbed as they encounter solid objects. Sound is transmitted through sohds in a complex array of types of elastic waves. Sound is charac terized by its amplitude, frequency, phase, and direction of propagation. 

Uhlig, Tierney and McClelland S measured fretting damage by mass loss of recessed 25-4 mm diameter steel cylinders subjected to radial oscillating motion. The specimens were loaded pneumatically, frequency was varied. 

They have also been operated with oscillating motion. 

Noordsij and Rotte (N10) studied mass transfer at a vibrating sphere. The oscillating motion was achieved by means of an attached rod, held by a spring against an eccentric wheel. The results, showing considerable scatter, are represented approximately by a Pe1/2 dependence, with an additive constant term accounting for pure diffusion. 

Oscillating motion of the conveyer causes reciprocating motion of the material which is unloated at the upper point of the conveyer. The granules are cooled and dried by clod air supplied by the fan. Thecooling air temperature iscontrolled within 20-40 °C. 

Fig. 8.2. Application of grease to joints and stopcocks, (a) Grease is applied in several thin stripes which run parallel to the direction of the male joint. A wooden splint may be used to apply the grease to avoid contamination by moisture or dust on fingers. (6) The joint is worked together with an oscillating motion and slight steady pressure.

Lap each part separately against a cast-iron lapping block. These blocks hold the lapping compound in their surface pores and must be recharged fre-quendy. Lap the block against the seat. Never rotate the block continuously, but use an oscillating motion. Extreme care should be taken throughout to make certain that the seats are kept perfecdy flat. 

With a lengthy derivation, the analytic solution for the preceding problem was provided by Lamb (1932). The resultant force on the sphere due to oscillating motion is obtained as... 

The sieve is hung on straps from the ceiling and is kept in oscillating motion by means of an eccentric driven from a compartment adjacent to that in which the screening installation is located. The end product is transported in leakproof chests or in paper-lined barrels. 

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