Dynamic machines

If turndown is a consideration, again the reciprocating compressor, with its many unloading options, does meet the challenge. This flexibility is difficult to achieve reliably in the dynamic machine and may require the compressor to operate at an unfavorable point on its characteristic curve. 

The unique natural frequencies of dynamic machine components are determined by the mass, freedom of movement, support stiffness, and other factors. These factors define the response characteristics of the rotor assembly (i.e., rotor dynamics) at various operating conditions. 

Centrifugal pumps are dynamic machines, which means that they convert velocity into feet of head. 

Centrifugal compressors are dynamic machines. They convert velocity, imparted to the gas by a spinning wheel, to poly tropic feet of head. The feet of head, multiplied by the density of the gas, equals the pressure boost produced by the centrifugal compressor. 

Note, however, that the concept of the entropy production rate is of critical importance for analyzing the evolution of systems that are close to equilibrium rather than of dynamic systems, which are described by rigid kinetic schemes with time deterministic behavior ( dynamic machines ). 

Several typologies of blowers or compressors are potentially suitable for fuel cell application. In Fig. 4.4 a flow diagram of all compressor types is reported, distinguishing two main classes (dynamic and positive displacement) and different typologies for each (reciprocating and rotary as positive displacement devices, and centrifugal and axial as dynamic machines). 

In a Brownian dynamics machine simulation, the configuration-space trajectories are composed of successive displacements rf —> rj over a short time-step At. The equation of motion is ... 

There are two general ways to compress gas in a refinery. Either a positive-displacement or a dynamic-type machine can be used. A reciprocating compressor is an example of a positive-displacement machine, whereas a centrifugal compressor is a dynamic machine. Centrifugal compressors are relatively ... 

Another commonly quoted value is the ratio of the maximum trough acceleration to g (as opposed to the previously defined vertical acceleration ratio), K, the dynamic machine... 

Dynamic machine Centrifugal pumps and centrifugal compressors are dynamic machines. They convert velocity imparted by the impeller to the fluid into fluid pressure. 

Dynamic machines Pumps or compressors that convert velocity into feet... 

Maletsky LP, Qary CW, Guess TM, Mane AM, Reeve AN. In vitro simulation of deep knee flexion using static and dynamic machines. Proc. ASME 2008 Summer Bioengineering Conference (SBC2008). Marco Island. Rorida, USA. 

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