Unbalance Response of a Dual Rotor System: Theory and Experiment

1993 ◽  
Vol 115 (4) ◽  
pp. 427-435 ◽  
Author(s):  
K. Gupta ◽  
K. D. Gupta ◽  
K. Athre
Keyword(s):  
System Theory ◽  
Transfer Matrix ◽  
Mode Shape ◽  
Reasonable Agreement ◽  
Complex Variables ◽  
Rotor System ◽  
Experimental Results ◽  
Unbalance Response ◽  
Theoretical Results ◽  
Theory And Experiment

A dual rotor rig is developed and is briefly discussed. The rig is capable of simulating dynamically the two spool aeroengine, though it does not physically resemble the actual aeroengine configuration. Critical speeds, mode shape, and unbalance response are determined experimentally. An extended transfer matrix procedure in complex variables is developed for obtaining unbalance response of dual rotor system. Experimental results obtained are compared with theoretical results and are found to be in reasonable agreement.

Theoretical and experimental investigation of the function of the wall flow deflecting ring. A single ring

1985 ◽  
Vol 50 (12) ◽  
pp. 2685-2696 ◽  
Author(s):  
Vladimír Staněk ◽  
Krumm Semkov ◽  
Nikolai Kolev ◽  
Georgii Paskalev
Keyword(s):  
Experimental Investigation ◽  
Theoretical Model ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Single Ring ◽  
The Future ◽  
Wall Flow ◽  
Trickle Bed ◽  
Theoretical Results

Theoretical model has been formulated of the flow of liquid in a randomly packed trickle bed column equipped with special wall flow deflecting rings (WFDR). Solutions have been obtained of the model for the case of a single ring. Theoretical results have been compared with experimental distributions of liquid in a 188.6 mm in diameter column packed with 25 mm Raschig rings and equipped with a single WFDR. Reasonable agreement of the theory with experimental results has been found and the theory is felt to be important in the future for optimizations of the number, size and spacing of the WFDR's to be used in industrial columns to check the extent of the flow on the wall.

scholarly journals Effect of Rotary Inertia and Gyroscopic Moments on Dynamics of Two Spool Aeroengine Rotor

1993 ◽  
Author(s):  
K. Gupta ◽  
R. Kumar ◽  
M. Tiwari ◽  
O. Prakash
Keyword(s):  
Experimental Results ◽  
Rotary Inertia ◽  
Inertia Effect ◽  
Transfer Matrices ◽  
Critical Speeds ◽  
Unbalance Response ◽  
Lumped Masses ◽  
Theoretical Results

The main objective of the paper is to study the effect of rotary inertia and gyroscopic moments due to lumped masses on the dynamics of two spool aeroengine rotors. Since the rotary inertia effect is well established, the thrust of the paper is on the effect of gyroscopic moments. Quantitative as well as qualitative aspects are studied. Effect of gyroscopics and rotary inertia on rotor critical speeds and unbalance response are studied for several rotors with particular reference to relative LP and HP rotor speeds. A two spool rig which resembles an actual aeroengine has been designed and built. Experiments have been conducted on two configurations of the rig in order to verify the theoretical results obtained by a formulation developed using the method of extended transfer matrices, for the two spool rotor with two intershaft bearings. A reasonably good correlation between the theoretical and experimental results is observed.

scholarly journals Investigation of the Steady-State Response of a Dual-Rotor System With Inter-Shaft Squeeze Film Damper

1985 ◽  
Author(s):  
Qihan Li ◽  
Litang Yan ◽  
James F. Hamilton
Keyword(s):  
Steady State ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Rotor System ◽  
Squeeze Film ◽  
Turbine Engine ◽  
Squeeze Film Damper ◽  
State Response ◽  
Unbalance Response

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc. The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.

Experimental Rotor Unbalance Response Using Hydrostatic Gas Lubrication

1973 ◽  
Vol 95 (4) ◽  
pp. 469-476 ◽  
Author(s):  
R. D. Dayton ◽  
M. R. Chasman
Keyword(s):  
Theoretical Model ◽  
Reasonable Agreement ◽  
Journal Bearings ◽  
Rotor Speed ◽  
Supply Pressure ◽  
Unbalance Response ◽  
Gas Lubrication ◽  
Theoretical Predictions ◽  
Theoretical Results

This paper investigates the adequacy of the theoretical model in predicting the unbalance response of a rotor supported in hydrostatic gas-lubricated journal bearings. The magnitude of experimental whirl amplitudes induced by applying various unbalances to a rotor supported in hydrostatic journal bearings were measured and compared to the theoretical predictions. Variables investigated were rotor unbalance, rotor speed, and bearing supply pressure. Reasonable agreement between the experimental and theoretical results was obtained.

Experimental Rotor Unbalance Response Using Hydrodynamic Gas Lubrication

1972 ◽  
Vol 94 (1) ◽  
pp. 74-80
Author(s):  
R. D. Dayton ◽  
M. R. Chasman
Keyword(s):  
Theoretical Model ◽  
Reasonable Agreement ◽  
Journal Bearings ◽  
Rotor Speed ◽  
Unbalance Response ◽  
Bearing Load ◽  
Gas Lubrication ◽  
Theoretical Predictions ◽  
Theoretical Results

This paper investigates the adequacy of the theoretical model in predicting the unbalance response of a rotor supported in hydrodynamic gas lubricated journal bearings. The magnitude of experimental whirl amplitudes induced by applying various unbalances to a rotor supported in hydrodynamic journal bearings were measured and compared to the theoretical predictions. Variables investigated were rotor unbalance, rotor speed, and bearing load. Reasonable agreement between the experimental and theoretical results was obtained.

Measurement of Li X-ray fluorescence production cross sections and intensity ratios of some elements at 59.54 keV

2015 ◽  
Vol 93 (10) ◽  
pp. 1057-1066 ◽  
Author(s):  
F. Akman ◽  
R. Durak ◽  
M.R. Kaçal ◽  
M.F. Turhan
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Reasonable Agreement ◽  
Production Cross ◽  
Radioactive Source ◽  
Experimental Results ◽  
X Ray ◽  
Intensity Ratios ◽  
Theoretical Results ◽  
Excitation Geometry

The Li (i = l, α, β, γ) X-ray production cross section and Lα/Ll, Lα/Lβ, Lα/Lγ, Ll/Lβ, Ll/Lγ, and Lβ/Lγ intensity ratio values for Yb, Ta, W, Hg, Tl, Pb, Bi, Th, and U have been determined using an excitation geometry at 59.54 keV incident photon energy. The measurements were performed using an Am-241 annular radioactive source and a high resolution Si(Li) detector. The experimental results of Li X-ray production cross sections and intensity ratios were compared with three different theoretical results and other available experimental results in the literature. Reasonable agreement is typically observed between the present and theoretical results.

Investigation of the Steady-State Response of a Dual-Rotor System With Intershaft Squeeze Film Damper

1986 ◽  
Vol 108 (4) ◽  
pp. 605-612 ◽  
Author(s):  
Qihan Li ◽  
Litang Yan ◽  
J. F. Hamilton
Keyword(s):  
Steady State ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Rotor System ◽  
Squeeze Film ◽  
Turbine Engine ◽  
Squeeze Film Damper ◽  
State Response ◽  
Unbalance Response

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc. The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.

A Comparison of Theoretical and Experimental Results From Spherical Shells With a Single Radially Attached Nozzle

1967 ◽  
Vol 89 (3) ◽  
pp. 333-338 ◽  
Author(s):  
F. J. Witt ◽  
R. C. Gwaltney ◽  
R. L. Maxwell ◽  
R. W. Holland
Keyword(s):  
Spherical Shell ◽  
Internal Pressure ◽  
Experimental Results ◽  
Strain Gages ◽  
Spherical Shells ◽  
Axial Thrust ◽  
Outside Diameter ◽  
Theoretical Results

A series of steel models having single nozzles radially and nonradially attached to a spherical shell is presently being examined by means of strain gages. Parameters being studied are nozzle dimensions, length of internal nozzle protrusions, and angles of attachment. The loads are internal pressure and axial thrust and moment loadings on the nozzle. This paper presents both experimental and theoretical results from six of the configurations having radially attached nozzles for which the sphere dimensions are equal and the outside diameter of the attached nozzle is constant. In some instances the nozzle protrudes through the vessel.

scholarly journals Would depositors pay to show that they do not withdraw? Theory and experiment

2020 ◽  
Vol 23 (3) ◽  
pp. 873-894
Author(s):  
Markus Kinateder ◽  
Hubert János Kiss ◽  
Ágnes Pintér
Keyword(s):  
Multiple Equilibria ◽  
Financial Intermediation ◽  
Type Model ◽  
Unique Equilibrium ◽  
Equilibrium Outcome ◽  
Bank Run ◽  
Public Announcements ◽  
Information Sets ◽  
Theoretical Results ◽  
Theory And Experiment

Abstract In a Diamond–Dybvig type model of financial intermediation, we allow depositors to announce at a positive cost to subsequent depositors that they keep their funds deposited in the bank. Theoretically, the mere availability of public announcements (and not its use) ensures that no bank run is the unique equilibrium outcome. Multiple equilibria—including bank run—exist without such public announcements. We test the theoretical results in the lab and find a widespread use of announcements, which we interpret as an attempt to coordinate on the no bank run outcome. Withdrawal rates in general are lower in information sets that contain announcements.

Experimental Study on the Failure Criterion for Brittle Materials in Compression

2011 ◽  
Vol 320 ◽  
pp. 259-262
Author(s):  
Xu Ran ◽  
Zhe Ming Zhu ◽  
Hao Tang
Keyword(s):  
Thin Film ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Failure Criterion ◽  
Brittle Materials ◽  
Experimental Results ◽  
Experiment Study ◽  
Confining Stress ◽  
Theoretical Results

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.

Sign in / Sign up

Export Citation Format

Share Document