Pulse Propagation in Straight and Curved Beams—Theory and Experiment

1974 ◽  
Vol 41 (1) ◽  
pp. 71-76 ◽  
Author(s):  
F. B. Crowley ◽  
J. W. Phillips ◽  
C. E. Taylor
Keyword(s):  
Method Of Characteristics ◽  
Pulse Propagation ◽  
Curved Beam ◽  
Curved Beams ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Isochromatic Fringe ◽  
Fringe Patterns ◽  
Theory And Experiment ◽  
Good Agreement

The equations from Morley’s one-dimensional theory governing the motion of a curved beam subjected to an arbitrary pulse are solved numerically using the method of characteristics. Propagation of initially longitudinal pulses in beam assemblages with both straight and curved sections is investigated. Simulated isochromatic fringe patterns are constructed by a Calcomp plotter and are compared with actual photoelastic patterns. Remarkably good agreement is found between theory and experiment in all the cases investigated. It is concluded that Morley’s theory can be applied to pulse propagation problems of the type investigated.

scholarly journals Pulse Propagation in a Helix—Theory and Experiment

1974 ◽  
Vol 41 (4) ◽  
pp. 1047-1051 ◽  
Author(s):  
J. W. Phillips
Keyword(s):  
Experimental Model ◽  
Strain Gage ◽  
Method Of Characteristics ◽  
Pulse Propagation ◽  
Numerical Results ◽  
Interface Problem ◽  
One Dimensional ◽  
The Method Of Characteristics ◽  
Theory And Experiment

Wittrick’s general one-dimensional equations governing the propagation of small elastic disturbances in a helical waveguide are solved by the method of characteristics, and numerical results for a particular interface problem are compared with strain gage records from an impacted experimental model. The agreement between theory and experiment is found to be excellent for the type of pulse considered, namely, an initially longitudinal compressive pulse approximately seventy rod-diameters in length.

On an Approximate Method of Calculating Pressures on Non-lifting Head Shapes at Supersonic Speeds

1955 ◽  
Vol 6 (1) ◽  
pp. 31-45
Author(s):  
H. K. Zienkiewicz
Keyword(s):  
Method Of Characteristics ◽  
Order Theory ◽  
Stagnation Pressure ◽  
Slender Body Theory ◽  
Pressure Losses ◽  
The Method Of Characteristics ◽  
Curvature Approximation ◽  
Body Theory ◽  
Theory And Experiment ◽  
Good Agreement

SummarySlender-body theory is used to derive the ogive of curvature approximation for very slender, pointed, convex head shapes at supersonic speeds. Results of application of this approximation, together with the λ-method for circular arc ogives, to a variety of non-slender head shapes show very good agreement with the method of characteristics, van Dyke's second-order theory and experiment. Good agreement with the method of characteristics and with experiment is obtained even in cases when the stagnation pressure losses across the nose shock wave are not negligible.

scholarly journals Study of Unsteady Flow in a Heat Exchanger by the Method of Characteristics

1992 ◽  
Vol 114 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Mao Huang
Keyword(s):  
Heat Exchanger ◽  
Unsteady Flow ◽  
Transfer Rate ◽  
Method Of Characteristics ◽  
Governing Equations ◽  
One Dimensional ◽  
The Method Of Characteristics ◽  
Improvement Factor ◽  
The One ◽  
Good Agreement

The one-dimensional, unsteady flow in an air-to-air heat exchanger is studied. The governing equations are derived and the method of characteristics with the uniform interval scheme is used in the analysis. The effect of the fin improvement factor on the air temperature in the heat exchanger and the heat transfer rate of the heat exchanger, and air properties in the heat exchanger are analyzed. The numerical results are compared and show good agreement with the available data.

scholarly journals Experimental Study on Nonlinear Vibrations of Fixed-Fixed Curved Beams

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Ajay Kumar ◽  
B. P. Patel
Keyword(s):  
Experimental Study ◽  
Internal Resonance ◽  
Nonlinear Vibrations ◽  
Excitation Amplitude ◽  
Curved Beam ◽  
Symmetric Mode ◽  
Curved Beams ◽  
Direct Excitation ◽  
First Time ◽  
Good Agreement

AbstractNonlinear dynamic behavior of fixed-fixed shallow and deep curved beams is studied experimentally using non-contact type of electromagnetic shaker and acceleration measurements. The frequency response obtained from acceleration measurements is found to be in fairly good agreement with the computational response. The travellingwave phenomenon along with participation of higher harmonics and softening nonlinearity are observed. The experimental results on the internal resonance of curved beams due to direct excitation of anti-symmetric mode are reported for the first time. The deep curved beam depicts chaotic response at higher excitation amplitude.

Precursor shock waves at a slow—fast gas interface

1976 ◽  
Vol 76 (1) ◽  
pp. 157-176 ◽  
Author(s):  
A. M. Abd–El–Fattah ◽  
L. F. Henderson ◽  
A. Lozzi
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Shock Wave ◽  
Shock Waves ◽  
Plane Shock ◽  
One Dimensional ◽  
Irregular Wave ◽  
Irregular Systems ◽  
Theory And Experiment ◽  
Good Agreement

This paper presents experimental data obtained for the refraction of a plane shock wave at a carbon dioxide–helium interface. The gases were separated initially by a delicate polymer membrane. Both regular and irregular wave systems were studied, and a feature of the latter system was the appearance of bound and free precursor shocks. Agreement between theory and experiment is good for regular systems, but for irregular ones it is sometimes necessary to take into account the effect of the membrane inertia to obtain good agreement. The basis for the analysis of irregular systems is one-dimensional piston theory and Snell's law.

Paper 2: Behaviour of Rarefaction Waves at the Junction of a Branched Duct

1969 ◽  
Vol 184 (7) ◽  
pp. 1-6
Author(s):  
D. H. Male ◽  
R. A. Chelsom ◽  
B. E. L. Deckker
Keyword(s):  
Method Of Characteristics ◽  
Side Branch ◽  
Pressure Measurements ◽  
Rarefaction Waves ◽  
One Dimensional ◽  
Pipe Networks ◽  
Schlieren Photography ◽  
Semi Empirical ◽  
Good Agreement ◽  
Made In

The results of an investigation into the behaviour of rarefaction waves at a junction formed by the intersection of two ducts are presented. Pressure measurements have been made in junctions in which the side branch forms an angle of 45°, 90°, and 135° with the main branch. In the 90° junction the effect of the area of the side branch to that of the main branch is examined; the values of the ratios being 1·0, 0·5, and 0·25. The amplitude of the incident rarefaction waves varies from 3 to 20 inHg. The development of the quasi-steady flow pattern has been obtained by Schlieren photography. This information, together with the pressure measurements, has been used to develop a quasi-steady, one-dimensional, semi-empirical analysis of the flow. The results of this analysis are in good agreement with the pressure measurements and can be used as boundary conditions for the examination of pipe networks by the method of characteristics.

A Type of Flame-Excited Oscillation in a Tube

1957 ◽  
Vol 24 (3) ◽  
pp. 333-339
Author(s):  
J. J. Bailey
Keyword(s):  
Experimental Results ◽  
Driving Mechanism ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Excited Oscillation ◽  
Damping Effects ◽  
Good Agreement

Abstract Propane-air mixtures were burned in an effectively open-ended tube containing a screen flameholder. Two types of instability were observed. Of these, one is described in some detail. A driving mechanism is proposed and examined in the light of Rayleigh’s criterion. Finally, a linear, one-dimensional theory is presented, taking into account both the driving and damping effects in the system. The predictions of this theory are shown to be in good agreement with the experimental results.

Experimental Verification and Measurement of Recompaction Waves Induced by Bulk Cavitation

1983 ◽  
Vol 197 (2) ◽  
pp. 141-144 ◽  
Author(s):  
M R Driels
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Free Surface ◽  
Fluid Motion ◽  
Laboratory Simulation ◽  
Dimensional Theory ◽  
Underwater Shock Wave ◽  
One Dimensional ◽  
Underwater Shock ◽  
Theory And Experiment

A brief review of an existing theory is given for the fluid motion following reflection of an underwater shock wave from a free surface. This one-dimensional theory is tested against experimental data obtained from simple apparatus designed for laboratory simulation of underwater shock. Correlation between theory and experiment is good.

Sign in / Sign up

Export Citation Format

Share Document