On the effects of a general form of the initial runout on the oscillation frequencies and critical speeds of a spinning disk

2011 ◽  
Vol 330 (26) ◽  
pp. 6435-6455 ◽  
Author(s):  
Ramin M.H. Khorasany ◽  
Stanley G. Hutton
Keyword(s):  
Critical Speeds ◽  
Spinning Disk ◽  
Oscillation Frequencies

Dynamics Behavior of a Guided Spline Spinning Disk, Subjected to Conservative In-Plane Edge Loads, Analytical and Experimental Investigation

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Ahmad Mohammadpanah ◽  
Stanley G. Hutton
Keyword(s):  
Degrees Of Freedom ◽  
Natural Frequencies ◽  
Linear Equations ◽  
Transverse Motion ◽  
Stable Operation ◽  
Lateral Direction ◽  
Critical Speeds ◽  
Spinning Disk ◽  
Inner Radius ◽  
Work Done

The governing linear equations of transverse motion of a spinning disk with a splined inner radius and constrained from lateral motion by guide pads are derived. The disk is driven by a matching spline arbor that offers no restraint to the disk in the lateral direction. Rigid body translational and tilting degrees-of-freedom are included in the analysis of total motion of the spinning disk. The disk is subjected to lateral constraints and loads. Also considered are applied conservative in-plane edge loads at the outer and inner boundaries. The numerical solution of these equations is used to investigate the effect of the loads and constraints on the natural frequencies, critical speeds, and stability of a spinning disk. The sensitivity of eigenvalues of spline spinning disk to the in-plane edge loads is analyzed by taking the derivative of the spinning disk's eigenvalues with respect to the loads. An expression for the energy induced in the spinning disk by the in-plane loads, and their interaction at the inner radius, is derived by computation of the rate of work done by the lateral component of the edge loads. Experimental idling and cutting tests for a guided spline saw are conducted at the critical speed, super critical speeds, and at the flutter instability speed. The cutting results at different speeds are compared to show that the idling results of a guided spline disk can be used to predict stable operation speeds of the system during cutting.

Transverse Vibration of a Rectangularly Orthotropic Spinning Disk, Part 2: Forced Vibration and Critical Speeds

1999 ◽  
Vol 121 (3) ◽  
pp. 280-285 ◽  
Author(s):  
A. Phylactopoulos ◽  
G. G. Adams
Keyword(s):  
Forced Vibration ◽  
Angular Speed ◽  
Point Load ◽  
Fourier Component ◽  
Amplitude Response ◽  
Disk Radius ◽  
Critical Speeds ◽  
Spinning Disk ◽  
Time Invariant ◽  
Orthotropic Disk

The transverse forced vibration of a rectangularly orthotropic spinning disk is investigated. The disk is subjected to a constant stationary point-load. Although the deflection of an isotropic disk under these loading conditions is time-invariant in a space-fixed coordinate system, the orthotropic disk undergoes time-dependent oscillatory motion. This phenomenon occurs as a result of the continually changing orientation of material properties with respect to the load. The disk deflection under-the-load is determined as a function of time. Also the deflection along a disk radius and circle containing the load are determined at a fixed instant of time. The occurrence of critical speeds is also investigated. Without damping, virtually any angular speed of the orthotropic disk is found to be critical. This behavior is due to the occurrence of more than one Fourier component in each of the eigenfunctions of the free vibration problem. With damping included, a large amplitude response is found at a speed much less than the lowest classical critical speed of an isotropic disk.

Formation of Standing Waves in Radial Tires

1984 ◽  
Vol 12 (1) ◽  
pp. 44-63 ◽  
Author(s):  
Y. D. Kwon ◽  
D. C. Prevorsek
Keyword(s):  
High Speed ◽  
Critical Speed ◽  
Unit Length ◽  
Standing Waves ◽  
Rolling Resistance ◽  
Damping Coefficient ◽  
Circular Membrane ◽  
Critical Speeds ◽  
Steel Cord ◽  
The Individual

Abstract Radial tires for automobiles were subjected to high speed rolling under load on a testing wheel to determine the critical speeds at which standing waves started to form. Tires of different makes had significantly different critical speeds. The damping coefficient and mass per unit length of the tire wall were measured and a correlation between these properties and the observed critical speed of standing wave formation was sought through use of a circular membrane model. As expected from the model, desirably high critical speed calls for a high damping coefficient and a low mass per unit length of the tire wall. The damping coefficient is particularly important. Surprisingly, those tire walls that were reinforced with steel cord had higher damping coefficients than did those reinforced with polymeric cord. Although the individual steel filaments are elastic, the interfilament friction is higher in the steel cords than in the polymeric cords. A steel-reinforced tire wall also has a higher density per unit length. The damping coefficient is directly related to the mechanical loss in cyclic deformation and, hence, to the rolling resistance of a tire. The study shows that, in principle, it is more difficult to design a tire that is both fuel-efficient and free from standing waves when steel cord is used than when polymeric cords are used.

scholarly journals Research on the Non-Magnetic Conductor of a PMSM Based on the Principle of Variable Exciting Magnetic Reluctance

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 318
Author(s):  
Chunyan Li ◽  
Fei Guo ◽  
Baoquan Kou ◽  
Tao Meng
Keyword(s):  
Permanent Magnet ◽  
Electromagnetic Force ◽  
Electromotive Force ◽  
Permanent Magnets ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Magnetic Conductor ◽  
Critical Speeds ◽  
Motor Structure ◽  
Test Result

A permanent magnet synchronous motor (PMSM) based on the principle of variable exciting magnetic reluctance (VMRPMSM) is presented. The motor is equipped with symmetrical non-magnetic conductors on both sides of the tangential magnetized permanent magnets (PMs). By placing the non-magnetic conductor (NMC), the magnetic reluctance in the exciting circuit is adjusted, and the flux weakening (FW) of the motor is realized. Hence, the NMC is studied comprehensively. On the basis of introducing the motor structure, the FW principle of this PMSM is described. The shape of the NMC is determined by analyzing and calculating the electromagnetic force (EF) acting on the PMs. We calculate the magnetic reluctance of the NMC and research on the effects of the NMC on electromagnetic force, d-axis and q-axis inductance and FW performance. The critical speeds from the test of the no-load back electromotive force (EMF) verify the correctness of the NMC design. The analysis is corresponding to the test result which lays the foundation of design for this kind of new PMSM.

scholarly journals Micromixing Efficiency in the Presence of an Inert Gas in a Rotor–Stator Spinning Disk Reactor

2021 ◽  
Author(s):  
Arturo N. Manzano Martínez ◽  
Arnab Chaudhuri ◽  
Matthijs Besten ◽  
Melissa Assirelli ◽  
John van der Schaaf
Keyword(s):  
Inert Gas ◽  
Spinning Disk
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