Pumping dynamics

SFE systems including continuous pumping, dynamic modifier addition, and a portable unit were from Isco, Inc. (Lincoln, NE). 

We elected to study coherent up-pumping dynamics in solution-phase metal-hexacarbonyl systems because of their strong vibrational infrared absorption cross sections, relatively simple ground-state spectra, and small (ca. 15 cm ) anharmonic overtone shifts. It was felt that these systems are ideal candidates to demonstrate that population control could be achieved for polyatomic species in solution because the excited state population... 

Pump Type Correction API Pump Dynamic Seal Pump Magnetic Drive Pump... 

R.J. Solaro, Integration of myofilament response to Ca2+ with cardiac pump regulation and pump dynamics, Am J Physiol 277(6 Pt 2), S155-63 (1999). 

Leaks, back pressure, and actuator dynamics all influence the performance of peristaltic pumps. Leaks and back pressure effects will alter the distribution of fluid as actuators open and close. The dynamics of the actuators determines the maximum actuatitm rate, which in turn limits the maximum flow rate. These effects can be incorporated into lumped-parameter models for analysis and simulation. We do not pursue this further in this entry, but refer the reader to the literamre. One general approach is presented in Ref. [7]. Also relevant for further smdy are Refs. [6, 8], and [13], which present dynamic models for pneumatic and electrostatic pumps, respectively. All of these works are applied to liquid pumps. For gas pumps, or robustness to bubbles, compressibility becomes a factor. Some considerations of micropumps for compressible fluids may be found in Ref. [1]. Finite-element analysis of individual chambers can also be used to obtain detailed predictions of pump dynamic performance. 

The COAST computer program is used to calculate the reactor coolant flow coast down transient for any combination of active and inactive pumps and forward or reverse flow in the hot or cold legs. The equations of conservation of momentum are written for each of the flow paths of the COAST model assuming unsteady one-dimensional flow of an incompressible fluid. The equation of conservation of mass is written for the appropriate nodal points. Pressure losses due to friction, and geometric losses are assumed proportional to the flow velocity squared. Pump dynamics are modelled using a head-flow curve for a pump at fiill speed and using four-quadrant curves, which are parametric diagrams of pump head and torque on coordinates of speed versus flow, for a pump at other than full speed. 

Operation of a Typical Multiport Vacuum Station Pumping Dynamics... 

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