Experimental investigation into transonic flows over tandem cavities

2001 ◽  
Vol 105 (1045) ◽  
pp. 119-124 ◽  
Author(s):  
N. Taborda ◽  
D. Bray ◽  
K. Knowles
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Mach Number ◽  
Pressure Distribution ◽  
Static Pressure ◽  
Transonic Flows ◽  
Wide Range ◽  
Different Dimensions

AbstractAn experimental study was conducted to analyse the pressure distribution along the floor of a cavity, with and without the presence of an upstream tandem cavity, at a constant freestream Mach number of about 0-911. Measurements were made for single cavities and the results compared with those obtained in the presence of an upstream tandem cavity. This comparison was made over a wide range of geometries, covering open to closed classes of cavities with both identical and different dimensions for the two cavities. The effect of the spacing between the two cavities was also studied. The downstream cavity is shown to be significantly affected by the presence of an upstream cavity, with both the overall net static pressure and its gradient being affected, dependent upon the class of cavity geometry and spacing under consideration.

CFD Predicted Discharge Coefficients of a Single Cylindrical Hole With Compressible External Cross-Flow

2009 ◽  
Author(s):  
L. Guo ◽  
Y. Y. Yan ◽  
J. D. Maltson
Keyword(s):  
Mach Number ◽  
Pressure Distribution ◽  
Inclination Angle ◽  
Film Cooling ◽  
Discharge Coefficient ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Cylindrical Hole ◽  
Static Pressure Distribution ◽  
Mainstream Flow

A computational investigation on discharge coefficient (Cd) of a single cylindrical hole is presented in this paper. The numerical calculations are carried out on a 3-D compressible model. The Shear-Stress Transport (SST) k–ω model is used to simulate the turbulence in the flow. The inclination angle (α) of the film cooling hole varies from 20° to 30°, 45° and 90°, respectively. The diameter of the hole is fixed at 10mm, but different coolant to mainstream pressure ratios (ptc/pm) are examined. The coolant Mach number (Mac) is set at a constant value of 0.3 and the mainstream flow Mach number (Mam) varies from 0.3 to 1.4. The effects of Mam and α on the Cd value as well as the static pressure distribution at the jet exit are investigated. The numerical results show an acceptable agreement in the trend of the Cd variation compare with the available experimental data. It has been predicted that the static pressure distribution in the vicinity of the jet exit is influenced by a number of factors including the mainstream flow Mach number, shock wave, jet inclination angle and the pressure ratio of the coolant to the mainstream flow. And then the static pressure field near the hole can further give strong influence on the discharge coefficient.

A Method for Correcting Wall Pressure Measurements in Subsonic Compressible Flow

1991 ◽  
Vol 113 (2) ◽  
pp. 256-260 ◽  
Author(s):  
C. Ducruet
Keyword(s):  
Boundary Layer ◽  
Experimental Investigation ◽  
Mach Number ◽  
Compressible Flow ◽  
Velocity Gradient ◽  
Static Pressure ◽  
Subsonic Flow ◽  
Diameter Ratio ◽  
Wall Pressure ◽  
Pressure Measurements

A theoretical and experimental investigation has been made of the static pressure hole problem in subsonic flow. Thanks to a linearization, the effects of the boundary layer, of the velocity gradient and of the wall curvature could be separated so that a formula of correction containing three influence functions has been obtained. These functions were determined in the case of practical requirements by means of experiments made on appropriate models for two values of the depth-to-diameter ratio and for at least three values of the Mach number. Then, the method of correction has been applied to the flow around an airfoil at zero angle of attack.

scholarly journals Mechanical comparative analysis of three different types of sutures in different dimensions tendons: experimental study

2002 ◽  
Vol 10 (3) ◽  
pp. 35-41 ◽  
Author(s):  
Trajano Sardenberg ◽  
Sérgio Swain Müller ◽  
Chafi Facuri Neto ◽  
Gustavo Colani Barbosa ◽  
José Fernando El Murr ◽  
...  
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Comparative Analysis ◽  
Statistical Study ◽  
Ultimate Load ◽  
Left Limb ◽  
Different Types ◽  
Axial Traction ◽  
Different Dimensions ◽  
The Right

The aim of this experimental investigation was study of mechanical profile of three kinds of suture, between tendons with different dimensions. Were utilized 21 mongrel dogs ( 11males, 10 females) of wich were obtained the tendon comum flexor and tendon tibial cranial of both pelvic limbs. After the dissection of the tendons, suture was done, seven animal per group. The tendons utilized allways were from the right limb and from the left limb side utilized as control. After the suture, we performed axial traction tests, rate level of 30mm /min, using special jaws. After the test the machine's program informed the values of ultimate load, elongation and strain, and load elongation diagram. The results were submite to statistical study, that showed no difference between the technics utilized. The values of suture groups were smaller than the control, for ultimate load, and higher for elongation and strain.

Experimental Investigation of the Flow Between Corotating Disks

1970 ◽  
Vol 37 (3) ◽  
pp. 844-849 ◽  
Author(s):  
R. Adams ◽  
W. Rice
Keyword(s):  
Experimental Investigation ◽  
Laminar Flow ◽  
Uncertainty Analysis ◽  
Pressure Distribution ◽  
Analytical Model ◽  
Newtonian Fluid ◽  
Radial Pressure ◽  
Experimental Results ◽  
Wide Range ◽  
Incompressible Newtonian Fluid

Experimental results are presented for the flow of an incompressible Newtonian fluid, with full admission, between closely spaced corotating disks. The radial pressure distribution is shown to coincide very closely with analytical results for laminar flow earlier presented by other investigators, over a wide range of the parameters pertinent to the flow description. A referenced analytical model for laminar flow between corotating disks is thus given credence. The experimental arrangement and procedure are described and a supporting uncertainty analysis is presented.

Theoretical and Experimental Investigation of Compressible Flow through Convergent–Divergent Nozzles

2012 ◽  
Vol 452-453 ◽  
pp. 1277-1285
Author(s):  
Hocine Mzad ◽  
Mohamed Elguerri
Keyword(s):  
Experimental Investigation ◽  
Mach Number ◽  
Pressure Distribution ◽  
Compressible Flow ◽  
Compressible Flows ◽  
Theoretical Calculations ◽  
Flow Characteristics ◽  
Additional Information ◽  
Shock Location ◽  
Flow Through

The present paper is concerned with the study of compressible flow in a converging-diverging nozzle. From a theoretical and experimental investigation of the flow in an illustrative channel with convergent-divergent area variation, the behavior of the flow along the channel was found to be generally similar in trend to the flow in a stationary convergent-divergent nozzle. In compressible flows, the density and temperature variations are often significant. Therefore, the following study provides additional information on shock location, Mach number behavior and pressure distribution by varying nozzle length. The obtained curves show pressure distribution and Mach number along the two dimensioned nozzles which enable us to compare the experimental data with the theoretical calculations. Furthermore, interesting graphs are plotted which show the relationship between some nozzle parameters and flow characteristics.

scholarly journals Experimental Research on Wall Pressure Distribution in C-D Nozzle at Mach number 1.1 for Area Ratio 3.24

2019 ◽  
Vol 8 (2S3) ◽  
pp. 971-975 ◽  
Keyword(s):  
Experimental Investigation ◽  
Mach Number ◽  
Flow Field ◽  
Pressure Distribution ◽  
Pressure Ratio ◽  
Area Ratio ◽  
Wall Pressure ◽  
Circulation Zone ◽  
Nozzle Pressure Ratio ◽  
Nozzle Pressure

In this experimental investigation the work reported is about the influence of control on the flow field in the suddenly expanded duct at low supersonic Mach number. A Convergent-divergent (CD) nozzle was designed and fabricated out of brass material assembled with the suddenly expanded duct which was also made of brass material. At the re-circulation zone, the flow field was controlled by using the micro jets of 1 mm diameter as an orifice and the control was arranged at an interval of 90 degrees at 6.5 mm from the central axis of the main jet. The measured wall pressure distribution was presented for Mach number 1.1 for the duct diameter of 18 mm leading to the area ratio 3.24. The L/D ratio of the duct was varied from 1 to 10, and the nozzle pressure ratio (NPR) considered for the experiments was from 3, 5, 7, 9 and 11. The present results have demonstrated that the micro jets do not influence the flow field in the duct adversely and the flow field remained identical in the presence of control or absence of control

An experimental study of compressible combining flow at 45° T-junctions

2014 ◽  
Vol 229 (9) ◽  
pp. 1600-1610 ◽  
Author(s):  
Wenhui Wang ◽  
Zhenhua Lu ◽  
Kangyao Deng ◽  
Shuan Qu
Keyword(s):  
Experimental Study ◽  
Mach Number ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Measurement Data ◽  
Junction Flow ◽  
Wide Range ◽  
Loss Coefficients

Junction flow loss is one of the sources of flow losses in many engineering pipe systems. An experimental study was carried out in order to investigate the combining steady pressure loss coefficients at 45° T-junctions with three area ratios between lateral branch and main duct. Extensive measurement data were obtained at a wide range of Mach number (0.1–0.6) and mass flow rate ratios using air as the tested fluid. Comparative analysis of the results includes the pressure difference in the two flow paths of the junction, the effect of Mach number in common branch due to gas compressibility, as well as the loss coefficients with various geometry condition. The following conclusion is drawn: the total pressure loss coefficient ( K) was mainly dependent on the Mach number ( M3), mass flow rate ratio ( q), and area ratio ( a), while almost independent on Reynolds number. The results provide reference for the research of junction flow and can be valuable in the correction of the boundary condition in one-dimensional simulation models.

The Axisymmetric Impingement of Supersonic Air Jets on Cones

1980 ◽  
Vol 31 (1) ◽  
pp. 26-41 ◽  
Author(s):  
I.K. Jennions ◽  
B.L. Hunt
Keyword(s):  
Experimental Investigation ◽  
Mach Number ◽  
Pressure Distribution ◽  
Surface Pressure ◽  
Nozzle Exit ◽  
Ambient Pressure ◽  
Free Jet ◽  
Air Jets ◽  
Surface Pressure Distribution ◽  
Exit Mach Number

SummaryThis paper reports an experimental investigation into the impingement of three jets from a convergent, conically divergent nozzle on to three cones of apex angles 120°, 90° and 60°. The exit Mach number of the nozzle was 2.2 and the jets were produced by operating with ratios of nozzle lip pressure to ambient pressure of 1, 1.2 and 2. The cones were arranged symmetrically in the jets at nozzle to apex distances of 0, 1 and 2 times the nozzle exit diameter. Surface pressures and shadowgraph pictures are presented. The most striking feature of the flows is the shock pattern produced by the interaction between the cone shock and the jet shock. This pattern can take a wide variety of forms depending on the structure of the free jet and strongly influences the form of the surface pressure distribution. For the most part, the flows can be explained on the basis of inviscid behaviour.

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