Analysis of the dynamic characteristics of pressure transducers for studying respiratory mechanics at high frequencies

1989 ◽  
Vol 27 (5) ◽  
pp. 531-537 ◽  
Author(s):  
R. Farré ◽  
R. Peslin ◽  
D. Navajas ◽  
C. Gallina ◽  
B. Suki
Keyword(s):  
Dynamic Characteristics ◽  
Respiratory Mechanics ◽  
High Frequencies ◽  
Pressure Transducers

Determination of the dynamic characteristics of adhesiveless strain gage pressure transducers

1989 ◽  
Vol 32 (1) ◽  
pp. 52-56 ◽  
Author(s):  
V. I. Pechuk ◽  
V. M. Zakharenko ◽  
V. Yu. Skripchuk ◽  
A. Yu. Shvets
Keyword(s):  
Strain Gage ◽  
Dynamic Characteristics ◽  
Pressure Transducers ◽  
Gage Pressure

A Dynamic Evaluation Technique for Liquid Flow Meters Based on Hydraulic Line Dynamics

1997 ◽  
Vol 119 (2) ◽  
pp. 305-307
Author(s):  
Guangzheng Peng ◽  
Tong Zhao
Keyword(s):  
Dynamic Characteristics ◽  
Liquid Flow ◽  
Experimental Verification ◽  
Microcomputer System ◽  
Evaluation Technique ◽  
Flow Meters ◽  
Pressure Transducers ◽  
Dynamic Technique ◽  
Frequency Domains ◽  
Flow Generator

A new concept for the evaluation of flowmeter dynamic response is presented. A technique based on hydraulic line dynamics is applied to achieve accurate measurements of the reference flowrate. The major components in the equipment used in experimental verification of the theory were a test pipe, a pulsating flow generator, three pressure transducers, an A/D converter, and a microcomputer system. This equipment allowed the dynamic characteristics of a flowmeter to be investigated in both the time and frequency domains. Comparisons of flowrates measured using the line dynamic technique and the same flowrates recorded by the flowmeter are presented. The results confirm the feasibility and practicability of the dynamic line technique for measuring rapidly varying flows.

Dynamic characteristics of air-filled differential pressure transducers

1979 ◽  
Vol 46 (3) ◽  
pp. 608-614 ◽  
Author(s):  
P. A. Proulx ◽  
A. Harf ◽  
H. Lorino ◽  
G. Atlan ◽  
D. Laurent
Keyword(s):  
Dynamic Characteristics ◽  
Differential Pressure ◽  
Pressure Transducers

Experimental Study on Unstable Characteristics of Mixed-Flow Pump at Low Flow-Rates

2003 ◽  
Author(s):  
Hiroshi Funakoshi ◽  
Hiroshi Tsukamoto ◽  
Koji Miyazaki ◽  
Kazuyoshi Miyagawa
Keyword(s):  
Unsteady Flow ◽  
Flow Rate ◽  
Dynamic Characteristics ◽  
Fast Response ◽  
Low Flow ◽  
Positive Slope ◽  
Mixed Flow ◽  
Flow Measurements ◽  
Pressure Transducers ◽  
Flow Pump

Static and dynamic characteristics of a mixed flow pump were measured at low flow rate, where the steady characteristic curves show a positive slope. Unsteady flow was measured at upstream and downstream of impeller, as well as on the casing wall of diffuser passage by using a fast response five-hole pitot tube and semi-conductor type pressure transducers. Dynamic response of the pump to the sinusoidal change in flow rate was measured under constant rotational speed. As a result of the unsteady flow measurements, the positive slope of steady characteristic was found to be caused by the impeller tip separation, inlet backflow, and pre-rotation. Moreover, the dynamic characteristics of the pump were found to become unstable with the increased frequency of flow rate.

Analysis of Pulsating Flows in Infinite and Finite Conical Nozzles

1969 ◽  
Vol 36 (2) ◽  
pp. 159-170 ◽  
Author(s):  
T. Chiang ◽  
F. C. Hsing ◽  
C. H. T. Pan ◽  
H. G. Elrod
Keyword(s):  
Mach Number ◽  
Dynamic Characteristics ◽  
Mass Flux ◽  
Nozzle Exit ◽  
Nozzle Geometry ◽  
Additional Parameter ◽  
Conical Nozzle ◽  
High Frequencies ◽  
Exit Mach Number ◽  
Flux Response

The pulsating flows in both infinite and finite conical nozzles were analyzed theoretically. Sinusoidal pressure disturbances were impressed at the nozzle exit for the infinite nozzle and at either the inlet or at the exit for the case of a finite nozzle. The results have been calculated in terms of mass-flux response. The parameters involved are the Mach number and the modified Strouhal number; the inlet and exit radii ratio enters as an additional parameter for a finite nozzle. The results for an infinite conical nozzle indicate that, when the frequency is low, the quasistatic relationship between the pressure and mass-flux fluctuations holds; the same was reported in reference [1]. But, as the frequency increases, the dynamic characteristics of the pulsating flow become important. And, at high frequencies, the mass-flux response is less than the quasistatic value by an amount depending on the Mach number. For a finite conical nozzle the quasistatic condition is still valid if the frequency is low. However, at higher frequencies, the dynamic behavior becomes critically dependent on the frequency expressed in terms of w, for a given nozzle geometry and exit Mach number.

Methods of determining the dynamic characteristics of pressure transducers

1986 ◽  
Vol 29 (2) ◽  
pp. 172-174
Author(s):  
�. S. Ostrovskii ◽  
V. A. Solomonik
Keyword(s):  
Dynamic Characteristics ◽  
Pressure Transducers

Quasi-Periodic Oscillations in Dwarf Novae

1979 ◽  
Vol 46 ◽  
pp. 77-88
Author(s):  
Edward L. Robinson
Keyword(s):  
Binary Systems ◽  
Outer Edge ◽  
Light Curves ◽  
Close Binary ◽  
Bright Spot ◽  
Dwarf Novae ◽  
Periodic Oscillations ◽  
High Frequencies ◽  
Short Period ◽  
Typical Time

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

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