An Experimental Study of Rectilinear Jet-Flap Cascades

1972 ◽  
Vol 94 (1) ◽  
pp. 97-104 ◽  
Author(s):  
T. J. Landsberg ◽  
E. Krasnoff
Keyword(s):  
Experimental Study ◽  
Momentum Flux ◽  
Two Dimensional ◽  
Trailing Edge ◽  
Tangential Blowing ◽  
Theoretical Results ◽  
Good Agreement

The performance of two-dimensional jet-flap cascades is determined experimentally. Stream deflection angles are presented as a function of the ratio of jet to mainstream momentum flux at chord spacing ratios of 0.375 and 0.75. Results obtained with conventional jet-flap airfoils (normal blowing near trailing edge) are in good agreement with published theoretical results. Tangential blowing jet-flap airfoils (tangential blowing over a rounded trailing edge) are shown to approximately double the turning effectiveness of the cascade.

Part II: Steady aerofoil-spoiler characteristics

1987 ◽  
Vol 91 (908) ◽  
pp. 359-366
Keyword(s):  
Separated Flow ◽  
Experimental Results ◽  
Surface Singularity ◽  
Separation Region ◽  
Two Dimensional ◽  
Trailing Edge ◽  
Singularity Method ◽  
Total Head ◽  
Low Speeds ◽  
Theoretical Results

Summary A surface singularity method has been formulated to predict two-dimensional spoiler characteristics at low speeds. Vorticity singularities are placed on the aerofoil surface, on the spoiler surface, on the upper separation streamline from the spoiler tip and on the lower separation streamline from the aerofoil trailing edge. The separation region is closed downstream by two discrete vortices. The flow inside the separation region is assumed to have uniform total head. The downstream extent of the separated wake is an empirical input. The flows both external and internal to the separated regions are solved. Theoretical results have been obtained for a range of spoiler-aerofoil configurations which compare reasonably with experimental results. The model is deficient in that it predicts a higher compression ahead of the spoiler than obtained in practice. Furthermore, there is a minimum spoiler angle below which a solution is not possible; it is thought that this feature is related to the physical observation that at small spoiler angles, the separated flow from the spoiler reattaches on the aerofoil upper surface ahead of the trailing edge.

Design and control of a two-dimensional telerobotic system with a haptic interface

2003 ◽  
Vol 217 (3) ◽  
pp. 169-185
Author(s):  
M-G Her ◽  
M Karkoub ◽  
K-S Hsu
Keyword(s):  
Haptic Interface ◽  
Two Dimensional ◽  
Direct Drive ◽  
Closed Loop System ◽  
Human Arm ◽  
Control Scheme ◽  
Reaction Forces ◽  
And Control ◽  
Theoretical Results ◽  
Good Agreement

A model for a ‘master-slave’ two-dimensional telerobotic dynamic system with a haptic interface device is derived. The telerobotic system consists of a ‘master’ robot, which is a direct-drive robot operated by a human arm, and a ‘slave’ robot, which is an x-y type pallet located at a remote site. When the active handle of the master is moved along an arbitrary trajectory, the remote slave duplicates the motion in a constrained or unconstrained environment. The behaviour of the environment is felt by the operator through the active handle of the master. This is achieved by feeding back the disturbance and reaction forces from the environment and the loads to the active handle. Consequently, the operator gets a feel of the task being performed without being physically at the location of the task. A control scheme is devised for the telerobotic system to establish smooth communication between the master and slave robots. This control scheme integrates the dynamics of the human arm, actuators and the environment in the closed-loop system. It was shown that the experimental and the theoretical results are in good agreement and that the design controller is robust to constrained/unconstrained environments.

scholarly journals Added Mass and Damping of a Vibrating Rod in Confined Viscous Fluids

1976 ◽  
Vol 43 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. S. Chen ◽  
M. W. Wambsganss ◽  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Cylindrical Shell ◽  
Closed Form Solution ◽  
Added Mass ◽  
Form Solution ◽  
Viscous Fluids ◽  
Series Of Experiments ◽  
Theoretical Results ◽  
Good Agreement

This paper presents an analytical and experimental study of a cylindrical rod vibrating in a viscous fluid enclosed by a rigid, concentric cylindrical shell. A closed-form solution for the added mass and damping coefficient is obtained and a series of experiments with cantilevered rods vibrating in various viscous fluids is performed. Experimental data and theoretical results are in good agreement.

ON THE STRUCTURE OF RESONANCE ZONES AND CHAOS IN NONLINEAR PARAMETRIC SYSTEMS

1994 ◽  
Vol 04 (02) ◽  
pp. 401-410
Author(s):  
ALBERT D. MOROZOV
Keyword(s):  
Two Dimensional ◽  
Resonance Case ◽  
Oscillatory Systems ◽  
Resonance Zone ◽  
Analytical Results ◽  
Time Systems ◽  
Theoretical Results ◽  
Parametric Systems ◽  
Good Agreement

Periodic-in-time systems close to two-dimensional nonlinear Hamiltonian ones are analyzed in the case when a perturbation contains nonlinear parametric terms and it is nonconservative. The existence of new regimes in the resonance zone, regular two-frequency regimes and non-regular “quasi-attractors,” is determined. The problem of transition from a resonance case to a nonresonance one for a changing detuning is solved on the basis of the analysis of shortened auto-oscillatory systems that determine the topology of the resonance zones. The theoretical results of this investigation are illustrated on a computer for a specific example. In the quasi-conservative case the numerical and analytical results are in good agreement.

scholarly journals STANDING WAVES IN FRONT OF A SLOPING DIKE

1972 ◽  
Vol 1 (13) ◽  
pp. 86 ◽  
Author(s):  
Nobuo Shuto
Keyword(s):  
Simple Formula ◽  
Standing Waves ◽  
Lagrangian Description ◽  
Two Dimensional ◽  
Constant Depth ◽  
Wave Pressure ◽  
Eulerian Description ◽  
Theoretical Results ◽  
Crest Height ◽  
Good Agreement

A solution of two-dimensional long waves on a beach of uniform slope is connected with that in water of constant depth, in order to yield an approximate solution for standing waves in front of a sloping dike. Wave motions are expressed in the Lagrangian description. The highest possible standing waves as well as the reflection coefficient are calculated according to the Miche's conception. Theoretical results show a good agreement with the experimental results of Murota and Yamada. It is also predicted that there is a relationship between the wave overtopping quantity and the quantity of water of standing waves above the crest height of the dike. As for the wave pressure of standing waves, a simple formula in the Eulerian description is derived for relative-dike length -t/L < 0.16 by allowing 670 error.

scholarly journals A THEORETICAL AND EXPERIMENTAL STUDY OF UNDERTOW

1984 ◽  
Vol 1 (19) ◽  
pp. 151 ◽  
Author(s):  
J. Buhr Hansen ◽  
I.A. Svendsen
Keyword(s):  
Experimental Study ◽  
Mass Flux ◽  
Laboratory Experiments ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Rip Currents ◽  
Longshore Currents ◽  
Theoretical Results ◽  
Recent Laboratory

It is well known that on a three-dimensional beach large volumes of water carried shorewards by the breakers feed longshore currents, which eventually escape back through the breaker line, often as rip currents. In a steady two-dimensional situation, however, the mass flux represented by (among other things) the surface roller in the breakers returns as a seaward current close to the bottom. This current is called the undertow. In this paper theoretical results for the undertow are compared with the results of recent laboratory experiments.

Torque and Cavitation Characteristics of Butterfly Valves

1961 ◽  
Vol 28 (4) ◽  
pp. 511-518 ◽  
Author(s):  
Turgut Sarpkaya
Keyword(s):  
Approximate Solution ◽  
Three Dimensional ◽  
Relaxation Technique ◽  
Dimensional Case ◽  
Practical Case ◽  
Two Dimensional ◽  
Actual Flow ◽  
Theoretical Results ◽  
Good Agreement

The present study deals with torque and cavitation characteristics of idealized two-dimensional and axially symmetrical butterfly valves. Theoretical results obtained for the two-dimensional case are compared with the ones obtained experimentally and by a relaxation technique. Based on the results of the two-dimensional case, an approximate solution is presented for the more general and practical case of three-dimensional butterfly valves. The results are in good agreement with the actual flow tests.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

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