Experimental investigation of enhancements in scattered pressure field of fluid‐loaded shell with periodic structure

1993 ◽  
Vol 93 (4) ◽  
pp. 2413-2413 ◽  
Author(s):  
Douglas M. Photiadis ◽  
Brian H. Houston ◽  
Jonathan E. Spanier
Keyword(s):  
Experimental Investigation ◽  
Periodic Structure ◽  
Pressure Field

High-Frequency Yarn Tension Variations in Spinning

1980 ◽  
Vol 102 (1) ◽  
pp. 45-50
Author(s):  
E. Dyson ◽  
G. Afshari
Keyword(s):  
Experimental Investigation ◽  
Periodic Structure ◽  
Coefficient Of Variation ◽  
Rotational Speed ◽  
High Frequency ◽  
Ring Spinning ◽  
Statistical Parameters ◽  
Yarn Tension ◽  
Rotor Spinning

A description of an experimental investigation of the variations in yarn tension during both ring and rotor open-end spinning which have frequencies equal to, or greater than, the rotational speed of the system is given. Typical results are illustrated and discussed both in terms of statistical parameters such as the coefficient of variation and in terms of their spectra. Tension variations during rotor spinning are shown to have, in general, a much less pronounced periodic structure then the corresponding variations during ring spinning.

Experimental Investigation of Flow Induced Rotor Oscillations in a Centrifugal Sewage Water Pump

Volume 3 ◽  
2004 ◽  
Author(s):  
Friedrich-Karl Benra ◽  
Hans Josef Dohmen ◽  
Oliver Schneider
Keyword(s):  
Experimental Investigation ◽  
Static Pressure ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
Sewage Water ◽  
Water Pump ◽  
Flow Rates ◽  
Pump Rotor ◽  
Pump Shaft ◽  
Impeller Geometry

Most of the pumps for sewage transport have a special impeller geometry in order to avoid operational disturbances by clogging. The almost exclusively used single stage machines particularly are equipped with single-blade impellers. With this impeller geometry a strongly uneven pressure field along the perimeter of the pump casing can be expected. The resulting periodically unsteady flow forces affect the impeller and produce strong radial deflections of the pump shaft. In this contribution the experimental investigation of the dynamic behavior of the pump rotor as a consequence of the transient hydrodynamic forces is described. To verify the calculated rotor oscillations measurements were performed at several rotating speeds and at different volume flow rates. The pump which before has been investigated numerical was equipped with several sensors. The deflections of the pump rotor were measured with two proximity sensors. The measurement of the vibration accelerations at the pump casing showed the effects of the transient hydrodynamic stimulation forces. Measurements of the static pressure in the casing allowed a correlation between the rotor oscillations and the pressure fluctuations produced by the single-blade impeller.

Theoretical and Experimental Investigation on Air Film Pressure Field Characteristics of Aerostatic Thrust Bearing

2021 ◽  
pp. 135065012110689
Author(s):  
Guoda Chen ◽  
Qi Lu ◽  
Yifan Ge ◽  
Wei Zhang
Keyword(s):  
Experimental Investigation ◽  
External Load ◽  
Thrust Bearing ◽  
Pressure Field ◽  
Measurement Equipment ◽  
Film Pressure ◽  
Theoretical Simulation ◽  
Simulation Results ◽  
Air Film ◽  
Theoretical Results

This paper studied the air film pressure field (AFPF) characteristics of aerostatic thrust bearing, in which we proposed the measurement equipment for the 2D AFPF and successfully verified the theoretical simulation results. The experimental results agreed well with the theoretical results. However, in the area between the distribution circle of orifice to the air film outlet boundary, the experimental air film pressure (AFP) was slightly higher than the theoretical one. While for the area between the distribution circle of orifice and the center of the bearing, it showed the opposite law. Besides, the increase ratio of the AFP was close to that of the external load with its increase.

scholarly journals Effect of Area Ratio on Base Pressure in a Suddenly Expanded Duct for Under Expanded Flow ft Mach 1.87

2013 ◽  
pp. 198-202
Author(s):  
M. Ahmed Ali Baig ◽  
Sher Afghan Khan ◽  
Mohammad Yunus Khan
Keyword(s):  
Experimental Investigation ◽  
Mach Number ◽  
Active Control ◽  
Pressure Field ◽  
Area Ratio ◽  
Wall Pressure ◽  
Base Pressure ◽  
Air Injection ◽  
Minimum Length ◽  
Percent Increase

The results of an experimental investigation carried out to control the base pressure in a suddenly expanded axi-symmetric passage is presented in this paper. An active control in the form of micro jets is employed to control the base pressure. Air injection at four locations at the base, symmetric to the nozzle axis is used as the active control. The jet Mach number studied and the area ratios are 1.87, and 2.56, 3.24, 4.84, and 6.25. The L/D ratio is varied from 10 to 1. The experiments are conducted at a fixed level of under expansion (i.e. Pe/Pa = 1.5). In addition to base pressure, wall pressure field along the duct was also measured. As high as 80 percent increase in base pressure was achieved for certain combination of parameters of the present study. The minimum Length-todiameter ratio of the duct required is L/D = 2 for area ratios 6.25 and 4.84. Whereas, this requirement is L/D = 1 for area ratios 2.56 and 3.24.

Sign in / Sign up

Export Citation Format

Share Document