The Frequency Response of Pneumatic Lines With Branching

1973 ◽  
Vol 95 (2) ◽  
pp. 194-196 ◽  
Author(s):  
V. K. Ravindran ◽  
J. R. Manning
Keyword(s):  
Frequency Response ◽  
Three Dimensional ◽  
Experimental Results ◽  
Signal Frequency ◽  
Small Signal ◽  
Dimensional Effects ◽  
Constant Area ◽  
Theoretical Predictions

Some experimental results are presented for amplitude and phase of small signal frequency response of pneumatic lines in configurations with branching. The recent data of Franke, Malanowski, and Martin [1] is extended in two areas: 1 Phase as well as amplitude measurements were made. 2 Stepped and conical branches were studied as well as constant area branches. Agreement is good with theoretical predictions based on the Iberall-Nichols-Brown model [2, 3, 4] and a simple continuity model for branch junctions. Three-dimensional effects at junctions are apparently not significant for the small amplitudes (less than 0.1 psi) and range of frequencies (100 to 1000 Hz) studied.

Small Signal Frequency Response of laser diodes using a femtosectond frequency comb

2002 ◽  
Author(s):  
Ovidio Anton ◽  
G. Vaschenko ◽  
Dinesh Patel ◽  
Jon M. Pikal ◽  
Carmen S. Menoni
Keyword(s):  
Frequency Response ◽  
Frequency Comb ◽  
Laser Diodes ◽  
Signal Frequency ◽  
Small Signal

Stable and unstable nonlinear resonant response of hanging chains: theory and experiment

1993 ◽  
Vol 440 (1909) ◽  
pp. 345-364 ◽  
Keyword(s):  
Excitation Frequency ◽  
Three Dimensional ◽  
Harmonic Excitation ◽  
Numerical Results ◽  
Experimental Results ◽  
Distinct Region ◽  
Asymptotic Results ◽  
Sensitive Dependence ◽  
Theoretical Predictions ◽  
Hanging Chain

The three-dimensional nonlinear dynamics of a hanging chain, driven by harmonic excitation at the top, are studied first analytically and numerically, and then experimentally. Asymptotic results demonstrate a sensitive dependence on excitation frequency and amplitude. For moderately large excitation amplitudes there are distinct regions of stable two-dimensional and stable three-dimensional response as function of frequency, as well as a distinct region in which all steady-state solutions are unstable. Numerical results were obtained to verify the asymptotic solutions and investigate the dynamics within the irregular response region. Numerical results for even larger excitation amplitudes showed that large impulse-like tension forces cause the chain to lose tension over a region adjacent to its freely hanging end, and then collapse. Following the collapse, the chain configuration intersects itself. Experimental results confirm qualitatively and quantitatively the theoretical predictions. The experimental results also demonstrate the loss of tension and subsequent collapse of the chain at the predicted excitation amplitudes, as well as the intersection of the chain with itself.

Hydroelastic Instability of Low Aspect Ratio Control Surfaces

2004 ◽  
Vol 126 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Michael E. McCormick ◽  
Luca Caracoglia
Keyword(s):  
Aspect Ratio ◽  
Special Class ◽  
Three Dimensional ◽  
Added Mass ◽  
Experimental Results ◽  
Low Aspect Ratio ◽  
Dimensional Effects ◽  
Aspect Ratios ◽  
Modified Equations ◽  
Control Surfaces

As the operational speeds of surface ships and submarines increase, so does the probability that unwanted vibrations caused by the hydroelastic instability (flutter) of the special class of hydrofoils called control surfaces. These include rudders and diving planes. By nature, these are thick symmetric hydrofoils having low aspect ratios. The 3-D tip effects become more pronounced as the aspect ratio decreases. In the present study, the added-mass and circulation terms of the 2-D flutter equations are modified to include three-dimensional effects. The modifications are performed by introducing quasi-steady coefficients to each term. The results predicted by the modified equations are found to compare well with experimental results on a towed rectangular foil having an aspect ratio of one.

Sign in / Sign up

Export Citation Format

Share Document