scholarly journals Wake dynamics and surface pressure variations on two-dimensional normal flat plates

AIP Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 045209 ◽  
Author(s):  
Arman Hemmati ◽  
David H. Wood ◽  
Robert J. Martinuzzi
Keyword(s):  
Surface Pressure ◽  
Two Dimensional ◽  
Flat Plates

Generalisation of the Condition for Waviness in the Pressure Distribution on a Cambered Plate

1963 ◽  
Vol 67 (632) ◽  
pp. 529-530 ◽  
Author(s):  
E. Angus Boyd
Keyword(s):  
Pressure Distribution ◽  
Surface Pressure ◽  
Leading Edge ◽  
Metal Plate ◽  
Two Dimensional ◽  
Striking Result ◽  
Surface Pressure Distribution

Recently some data from tests done on a cambered plate have been published. The shape of metal plate aerofoil tested matched that taken up by a flexible two-dimensional sail. The most striking result in the rneasurements was the waviness present near the leading edge in the upper surface pressure distribution. To find the theoretical conditions under which such a waviness would occur a parabolic skeleton aerofoil was investigated, as this shape differed little from the actual aerofoil tested.

scholarly journals Some numerical experiments on firn ventilation with heat transfer

1993 ◽  
Vol 18 ◽  
pp. 161-165 ◽  
Author(s):  
M.R. Albert
Keyword(s):  
Heat Transfer ◽  
Surface Pressure ◽  
Thermal Effects ◽  
Numerical Experiments ◽  
Temperature Gradients ◽  
Pressure Amplitude ◽  
Two Dimensional ◽  
One Dimensional ◽  
Thermal Signature ◽  
Spatially Varying

Preliminary estimates of the thermal signature of ventilation in polar firn are obtained from two-dimensional numerical calculations. The simulations show that spatially varying surface pressure can induce airflow velocities of 10−5m s−1at 1.5 m depth in uniform firn, and higher velocities closer to the surface. The two-dimensional heat-transfer results generally agree with our earlier one-dimensional conclusions that the thermal effects of ventilation tend to decrease the temperature gradient in the top portions of the pack. Field observations of ventilation through temperature measurements are most likely to be observed when the firn temperature at depths on the order of 10 m is close to the air temperature, since steep temperature gradients can mask the thermal effects of ventilation. Preliminary indications are that, as long as surface-pressure amplitude is sufficient to move the air about in the top tens of centimeters in the snow, the resulting temperature profile during ventilation is fairly insensitive to the frequency of the surface-pressure forcing for pressure frequencies in the range 0.1–10.0 Hz.

Velocity profiles and fence drag for a turbulent boundary layer along smooth and rough flat plates

1976 ◽  
Vol 76 (2) ◽  
pp. 383-399 ◽  
Author(s):  
K. G. Ranga Raju ◽  
J. Loeser ◽  
E. J. Plate
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layers ◽  
Roughness Parameter ◽  
Velocity Profiles ◽  
Published Data ◽  
Two Dimensional ◽  
Flat Plates ◽  
Form Drag ◽  
Displacement Thickness

The properties of a turbulent boundary layer were investigated as they relate to the form drag on a two-dimensional fence. Detailed measurements were performed at zero pressure gradient of velocity profiles along smooth, rough and transitional flat plates. Upon comparison with other published data, these measurements resulted in simple formulae for the displacement thickness and the local shear coefficient and in a modification to the universal velocity defect law for equilibrium boundary layers.With these boundary layers, experiments were performed to determine the drag on a two-dimensional fence. These data were analysed along with data from previous investigations. It was found that after suitable blockage corrections all form-drag coefficients for two-dimensional fences collapsed on a single curve if they were calculated with the shear velocity as the reference velocity and plotted against the ratio of the fence height to the characteristic roughness parameter of the approaching flow.

A New Visualization Method for Harmonic Unsteady Flows in Turbomachinery

2016 ◽  
Author(s):  
Tobias Gezork ◽  
Paul Petrie-Repar ◽  
Torsten Fransson
Keyword(s):  
Unsteady Flow ◽  
Group Velocity ◽  
Forced Response ◽  
Test Cases ◽  
Visualization Method ◽  
Two Dimensional ◽  
Flat Plates ◽  
Linear Cascade ◽  
Field Lines ◽  
Turbomachinery Design

Understanding unsteady flow processes is key in the analysis of challenging problems in turbomachinery design such as flutter and forced response. In this paper a new visualization method for harmonic unsteady flow is presented. The method illustrates the direction in which unsteady waves are traveling and transporting energy by the direct visualization of the propagating pressure waves in terms of field lines constructed from the wave group velocity. The group velocity is calculated from the unsteady flow solution by assuming that the local unsteady pressure perturbation of interest can be represented by a single harmonic unsteady wave. The applicability of the method is demonstrated for three test cases including a linear cascade of two-dimensional flat plates and a linear cascade of two-dimensional compressor blade profiles.

A Free-Streamline Model for Bluff Bodies in Confined Flow

1977 ◽  
Vol 99 (3) ◽  
pp. 585-592 ◽  
Author(s):  
V. J. Modi ◽  
S. E. El-Sherbiny
Keyword(s):  
Potential Flow ◽  
Bluff Body ◽  
Flow Model ◽  
Circular Cylinders ◽  
Bluff Bodies ◽  
Two Dimensional ◽  
Flat Plates ◽  
Surface Loading ◽  
Confined Flow ◽  
Potential Flow Model

A potential flow model is presented for two-dimensional symmetrical bluff bodies under wall confinement. It provides a procedure for predicting surface loading on a bluff body over a range of blockage ratios. Experimental results with normal flat plates and circular cylinders for blockage ratios up to 35.5 percent substantiate the validity of the approach.

Resistance of Two Inclined Parallel Flat Plates Placed in Tandem on a Stream-Wise Flat Plate in Two-Dimensional Flow

1993 ◽  
Vol 207 (6) ◽  
pp. 393-397
Author(s):  
R C Mehta ◽  
C R Rao ◽  
Y N Dubey
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Flat Plate ◽  
Flow Direction ◽  
Considerable Extent ◽  
Appreciable Effect ◽  
Two Dimensional ◽  
Flat Plates ◽  
Dimensional Flow ◽  
Two Dimensional Flow

The paper presents the results of an experimental study on the drag coefficient of two inclined parallel flat plates, placed on a stream-wise flat plate, in tandem, in two-dimensional flow. The effects on the drag coefficient of Reynolds number, the inclination of the plates to the flow direction and the relative spacing between plates were studied. It is observed that, while the Reynolds number has no appreciable effect, the other parameters influence the drag coefficient to a considerable extent. The results are corrected for blockage effect and comparisons are made with the data collected by other investigators.

Waveless Free-Surface Pressure Distributions

1985 ◽  
Vol 29 (03) ◽  
pp. 151-158
Author(s):  
J.-M. Vanden Broeck ◽  
E. O. Tuck
Keyword(s):  
Free Surface ◽  
Surface Pressure ◽  
Free Surface Flows ◽  
Two Dimensional ◽  
Surface Flows ◽  
Pressure Distributions ◽  
Potential Applications ◽  
Linear And Nonlinear ◽  
Uniform Stream

Linear and nonlinear studies are made of two-dimensional free-surface flows under gravity, in which a disturbance is caused to an otherwise uniform stream by a distribution of pressure over the free surface. In general, such a disturbance creates a system of trailing waves. There are special disturbances that do not, however, and some categories of such disturbances are discussed here. This work has potential applications to design of splashless ship bows.

Sign in / Sign up

Export Citation Format

Share Document