scholarly journals Experimental Investigation on the Effect of Angles of Attack to the Flutter Speed of a Flat Plate in Axial Flow

2021 ◽  
Vol 21 (2) ◽  
pp. 111-116
Author(s):  
I Putu Gede Sopan Rahtika ◽  
◽  
I Made Suarta ◽  
I Komang Rusmariadi ◽  
Putu Wijaya Sunu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Wind Tunnel ◽  
Flat Plate ◽  
Experimental Research ◽  
Relative Position ◽  
Air Flow ◽  
Axial Flow ◽  
Flat Plates ◽  
Flutter Speed ◽  
Subsonic Wind Tunnel

The application of flat plates to the field of wind harvesting requires a lot of research toward the understanding of the flutter behavior of the plates. There are shortages of articles that discuss the effect of varying the angles of attack to the flutter speed of a flat plate. This research aims to conduct a basic experimental research on the effect of relative position of a thin-flat plates to the direction of the air flow to its flutter speed. In this study, a thin-flat plate was placed in a subsonic wind tunnel to test its flutter speed. The position of the plate was varied in various angles of attack. The effect of the angles of attack to the flutter speed was observed.

An Experimental Investigation of Natural Convection With Vertical Cylinders in Mercury

1974 ◽  
Vol 96 (4) ◽  
pp. 455-458 ◽  
Author(s):  
L. E. Wiles ◽  
J. R. Welty
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Natural Convection ◽  
Flat Plate ◽  
Convection Heat Transfer ◽  
Vertical Cylinder ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Transfer Coefficients ◽  
Flat Plates

An experimental investigation of laminar natural convection heat transfer from a uniformly heated vertical cylinder immersed in an effectively infinite pool of mercury is described. A correlation was developed for the local Nusselt number as a function of local modified Grashof number for each cylinder. A single equation incorporating the diameter-to-length ratio was formulated that satisfied the data for all three cylinders. An expression derived by extrapolation of the results to zero curvature (the flat plate condition) was found to agree favorably with others’ work, both analytical and experimental. The influence of curvature upon the heat transfer was found to be small but significant. It was established that the effective thermal resistance through the boundary layer is less for a cylinder of finite curvature than for a flat plate. Consequently, local heat transfer coefficients for cylinders are larger than those for flat plates operating under identical conditions.

scholarly journals Experimental Investigation of Water Droplet Phase Change in Humidi-fied Air Flow

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 197-205
Author(s):  
Virginijus RAMANAUSKAS ◽  
Linas PAUKŠTAITIS ◽  
Gintautas MILIAUSKAS ◽  
Egidijus PUIDA
Keyword(s):  
Experimental Investigation ◽  
Phase Change ◽  
Experimental Research ◽  
Water Droplet ◽  
Research Method ◽  
Air Flow ◽  
Equivalent Diameter ◽  
Initial Water ◽  
Humidified Air ◽  
Droplet Phase

An experimental research method and an analysis of the results of a water droplet phase change in the additionally humidified air flow are presented. The diagrams of variation of the equivalent diameter of convectively heated water droplets are presented and analysed. The influence of initial water temperature and additionally humidifying air flow on the phase change of a droplet in transient regime is experimentally substantiated.

scholarly journals Design procedure and honeycomb screen implementation to the air transtport department’s subsonic wind tunnel

AEROjournal ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 3-8
Author(s):  
Michal Hrúz ◽  
◽  
Pavol Pecho ◽  
Martin Bugaj
Keyword(s):  
Wind Tunnel ◽  
Air Flow ◽  
Design Procedure ◽  
Reynold Number ◽  
Air Transport ◽  
Wind Tunnels ◽  
Subsonic Wind Tunnel ◽  
Validation Of Results ◽  
Mathematical Relations ◽  
Test Objects

Wind tunnels are the most widely used tools when comes to validation of Reynold number. Most of wind tunnels use various air straighteners or flow conditioners to achieve as most unified air flow as it’s possible. This article deals with design and creation procedure of air flow straightener – honeycomb screen. Based on mathematical relations and empirical experience defines dimensions and characteristics for subsonic wind tunnel of the Air Transport Department of University of Žilina. Wind tunnel equipped with a suitable screen provides more relevant and accurate data, which are crucial for final validation of results of test objects.

scholarly journals Investigation of Throttling Characteristics in Supersonic Polyclinic Inlet

2019 ◽  
pp. 21-33
Author(s):  
D.A. Vnuchkov ◽  
V.I. Zvegintsev ◽  
D.G. Nalivaychenko
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Air Flow ◽  
Flow Restriction ◽  
Air Inlet ◽  
Additional Heating ◽  
Flat Flow ◽  
Good Agreement

This paper presents an experimental investigation of throttling characteristics of a multi-wedge air inlet of a wind tunnel built for flat flow field at M = 2.5. The experiments were performed in a wind tunnel at M numbers of 2.55, 3.05 and 4.05. Results of numerical simulation of the flow in the air inlet, where air flow restriction was implemented by additional heating of the flow in the channel past the air inlet, are given for comparison. Experimental throttling characteristics are in good agreement with the values obtained from computations

scholarly journals Experimental Investigation on Flutter Similitude of Thin-Flat Plates

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
I. P. G. Sopan Rahtika ◽  
I. N. G. Wardana ◽  
A. A. Sonief ◽  
E. Siswanto
Keyword(s):  
Reynolds Number ◽  
Dimensional Analysis ◽  
Axial Flow ◽  
Leading Edge ◽  
Dimensionless Number ◽  
Flat Plates ◽  
Dimensionless Numbers ◽  
Fluid Structure ◽  
Flutter Speed ◽  
Aspect Ratios

This paper shows the experimental results of the flutter speed of thin-flat plates with free leading edge in axial flow as a function of plates’ geometry, fluid densities, and viscosities, as well as natural frequencies of the plates. The experiment was developed based on similitude theory using dimensional analysis and Buckingham Pi Theorem. Dimensional analysis generates four dimensionless numbers. Experiment was conducted by placing the thin-flat plates in a laminar flow wind tunnel in order to obtain the relationship among those dimensionless numbers. The flutter speed was measured by varying the flow velocity until the instability occurred. The dimensional analysis gives a map of the flutter Reynolds number as a function of a new type of dimensionless number that is hereby called flutter fluid structure interaction number, thickness-to-length, and aspect ratios as the correcting factors. This map is a very useful tool for predicting the flutter speed of thin-flat plates in general. This investigation found that the flutter Reynolds number is very high at the region of high flutter fluid structure and thickness-to-length ratios numbers; however, it is very sensitive to the change of those two dimensionless numbers. The sensitivity is higher at lower aspect ratio.

Blockage Corrections for Rectangular Flat Plates Mounted in an Open Jet Wind Tunnel

1983 ◽  
Vol 197 (4) ◽  
pp. 259-263 ◽  
Author(s):  
A T Sayers ◽  
D R Ball
Keyword(s):  
Wind Tunnel ◽  
Flat Plate ◽  
Wind Velocity ◽  
Experimental Technique ◽  
Flow Direction ◽  
The Body ◽  
Wind Tunnels ◽  
Flat Plates ◽  
Projected Area

The correction that must be applied to the upstream wind velocity, when a rectangular flat plate normal to the flow direction is placed in an open jet wind tunnel, is determined and is found to be at all times equal to or greater than unity. It is also found to be dependent upon the distance of the body from the tunnel outlet, and the projected area of the body. Comparisons with previous work carried out in closed wind tunnels are made to confirm the experimental technique used.

Effects of Turbulence on the Breakup of Round Liquid Jets in Gaseous Crossflow

2005 ◽  
Author(s):  
R. Sankarakrishnan ◽  
K. A. Sallam ◽  
F. W. Chambers
Keyword(s):  
Experimental Investigation ◽  
Wind Tunnel ◽  
Test Section ◽  
Drop Size ◽  
Liquid Surface ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Surface Conditions ◽  
Subsonic Wind Tunnel ◽  
Primary Breakup

An experimental investigation of the effects of turbulence on primary breakup of round liquid jets subjected to gaseous crossflow is described. The paper investigates the effects of partial degrees of turbulence development in the liquid. Measurements of the properties of primary breakup were obtained using double-pulsed shadowgraphy in a subsonic wind tunnel having a test section of 0.3 m × 0.3 m × 0.6 m. Measurements included primary breakup regimes, conditions required for the onset of breakup, ligament properties along the liquid surface, drop size and velocity distributions after breakup along the liquid surface, conditions required for breakup of the liquid jet as a whole, and liquid jet trajectories.

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