Comparison of Computational Aeroacoustics Prediction of Acoustic Transmission through a Loaded 2D Rotor with Flat Plate Theory

2012 ◽  
Author(s):  
Ray Hixon
Keyword(s):  
Flat Plate ◽  
Plate Theory ◽  
Computational Aeroacoustics ◽  
Acoustic Transmission

Flush probe studies of plasma flow over a flat plate: theory

1979 ◽  
Vol 12 (10) ◽  
pp. 1685-1697 ◽  
Author(s):  
C R Giles ◽  
R M Clements ◽  
P R Smy
Keyword(s):  
Flat Plate ◽  
Plasma Flow ◽  
Plate Theory

A Simple Theory for the Two-Dimensional Compressible Turbulent Boundary Layer

1972 ◽  
Vol 94 (3) ◽  
pp. 636-642 ◽  
Author(s):  
F. M. White ◽  
G. H. Christoph
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Flat Plate ◽  
Skin Friction ◽  
Plate Theory ◽  
Momentum Equation ◽  
Shape Factors ◽  
Law Of The Wall ◽  
Compressible Turbulent Flow ◽  
New Equation

A new approach is proposed for analyzing the compressible turbulent boundary layer with arbitrary pressure gradient. Utilizing a compressible law-of-the-wall and a Crocco energy approximation, the new theory integrates the momentum equation across the boundary layer in terms of inner variables only. The result is a single first-order ordinary differential equation for skin friction, devoid of integral thicknesses and shape factors. When analyzed for flat plate flow, this new equation has an exact solution apparently superior in accuracy to any other flat plate theory (Table 1). The new equation also agrees well with supersonic skin friction data in both favorable and adverse pressure gradients. The new theory contains an explicit separation criterion and is the simplest and possibly most accurate existing analysis for compressible turbulent flow.

Experimental Analysis of Rudder Contribution to Roll Damping

2008 ◽  
Author(s):  
Ali Etebari ◽  
Paisan Atsavapranee ◽  
Christopher Bassler ◽  
Jason Carneal
Keyword(s):  
Flat Plate ◽  
Plate Theory ◽  
Added Mass ◽  
Sine Wave ◽  
Plate Model ◽  
Flat Plates ◽  
Roll Damping ◽  
Clear Trend ◽  
Current Effort ◽  
Drag And Lift

Measuring and modeling the forces on the appendages of surface ships is important for understanding roll-damping and validating numerical simulations. In recent years, Atsavapranee et al (2007) showed that the bilge keel damping component can be modeled using the flat plate theory established by Keulegan and Carpenter (1958). This model treats the bilge keels as a flat plate that generates viscous damping, as well as added mass. The model comes as an improvement to models used in computational codes used for predicting roll damping, due to the fact that the added mass component is significant. In this study, uncoupled roll motion is investigated to quantify the rudder forces on a fully appended DTMB model #5415 with instrumented appendages at Froude numbers of 0 and 0.138. The objective of the current effort is to decompose the rudder force into its steady, symmetric, and antisymmetric components using Fourier analysis. In the force analysis the rudders are treated as flat plates for the Fr = 0 tests, using the model described by Keulegan and Carpenter (1958). The drag and lift forces are consistent with the flat plate model. The anti-symmetric term, however, does not show a clear trend. For a flat plate model, the anti-symmetric term should resemble a negative sine wave with respect to roll. However, the rudders represent a higher aspect ratio flat plate, and thus require a modification to the added mass formulation. Furthermore, during a normal roll period they tend to interact with the free surface, which can lead to wave damping, which should resemble a positive sine wave with respect to roll. Thus, the two components of the anti-symmetric portion of the signal are superimposed upon one another. In an attempt to decouple these two components, the added mass was artificially removed from the antisymmetric component of the force. This paper will detail the methods used to model the rudder forces for both the standstill and positive Froude number cases.

On Classical Plate Theory and Wave Propagation

1961 ◽  
Vol 28 (2) ◽  
pp. 223-228 ◽  
Author(s):  
M. A. Medick
Keyword(s):  
Wave Propagation ◽  
Flat Plate ◽  
Surface Area ◽  
Plate Theory ◽  
Large Radius ◽  
Classical Plate Theory ◽  
Small Surface ◽  
Transient Loading ◽  
Small Surface Area

The purpose of this investigation is to assess the applicability of classical plate theory in describing the response of a flat plate of large radius to a sharp, transient loading applied over a small surface area by evaluating its predictions and comparing them with some preliminary experiments.

scholarly journals Euler Flow Predictions for an Oscillating Cascade Using a High Resolution Wave-Split Scheme

1991 ◽  
Author(s):  
Dennis L. Huff ◽  
Timothy W. Swafford ◽  
T. S. R. Reddy
Keyword(s):  
Flat Plate ◽  
Plate Theory ◽  
Unsteady Aerodynamics ◽  
Nonlinear Behavior ◽  
Splitting Scheme ◽  
Flow Equations ◽  
Euler Flow ◽  
Time Marching ◽  
Phase Angles ◽  
Flux Difference

A compressible flow code that can predict the nonlinear unsteady aerodynamics associated with transonic flows over oscillating cascades is developed and validated. The code solves the two-dimensional, unsteady Euler equations using a time-marching, flux-difference splitting scheme. The unsteady pressures and forces can be determined for arbitrary input motions, although this paper will only address harmonic pitching and plunging motions. The code solves the flow equations on a H-grid which is allowed to deform with the airfoil motion. Predictions are presented for both flat plate cascades and loaded airfoil cascades. Results are compared to flat plate theory and experimental data. Predictions are also presented for several oscillating cascades with strong normal shocks where the pitching amplitudes, cascade geometry and interblade phase angles are varied to investigate nonlinear behavior.

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