2 edition of Effects of Reynolds number, Mach number and sting geometry on rotary balance measurements found in the catalog.
Effects of Reynolds number, Mach number and sting geometry on rotary balance measurements
C. O. O"Leary
|Statement||by C. O. O"Leary, B. Weir.|
|Series||Technical memorandum aero -- 2192|
|Contributions||Weir, B., Royal Aerospace Establishment.|
large. As the Reynolds number IS increased loss of CL with increasing Mach number occurs later and becomes less severe (Fag. 7) and the value of Cm becomes more nose down (Fig. 12). The drag rise 1s also delayed by about in &oh number as the Reynolds number is. The Reynolds number Re then becomes: Re = (r * V * dV/dx) / (mu * d^2V/dx^2) Re = (r * V * L) / mu where L is some characteristic length of the problem. If the Reynolds number of the experiment and flight are close, then we properly model the effects .
The e•ect of Reynolds number on boundary layer turbulence David B. DeGraa• a,*, Donald R. Webster b, John K. Eaton a a Department of Mechanical Engineering, Stanford University, Bldg. , Rm. E, Stanford, CA , USA b School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlantic Drive, Atlanta, GA , USAFile Size: KB. Physically speaking, when the Reynolds numbers of two configurations are equal, the flow physics is roughly equivalent. I say roughly because it isn't the only non-dimensional number to relate -- there's also Mach number, Prandtl number, etc etc.. But, depending on the .
With the test speed set by volume ratio and Mach number, we are left with a variation in Reynolds number. According to ASME PTC , the performance of a compressor is affected by the Machine Reynolds number. Frictional losses in the internal flow passages vary in a manner similar to friction losses in pipes or other flow channels. Mach number: the ratio of the airspeed to the speed of sound should be identical for the scaled model and the actual object (having identical Mach number in a wind tunnel and around the actual object is -not- equal to having identical airspeeds) Reynolds number: the ratio of inertial forces to viscous forces should be kept. This parameter is difficult to satisfy with a scaled model and has led to development .
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In Reynolds number up to approximately 12× and Mach number up to approximately The results from the ONERA F1 test campaigns will be analyzed for Reynolds and Mach number effects (among other things) and compared to the results of the WSU test campaigns to determine the extent to which iced, swept-wing aerodynamicFile Size: 1MB.
Wing was tested with full-span, partial-span, or split flaps deflected 60 Degrees and without flaps. Chordwise pressure-distribution measurements were made for all flap configurations. Peak values of maximum lift coefficient were obtained at relatively low free-stream Mach numbers and, before critical Mach number was reached, were almost entirely dependent on Reynolds by: 5.
The effect of Reynolds and Mach number variation in compressible isothermal channel flow is investigated through a series of direct numerical simulations (DNS), at bulk Mach number M b =3 and bulk Reynolds number up to Re b =which is sufficient to sense sizeable high-Reynolds-number effects not reached before in this type of by: The most bluff geometry has a larger recirculation region, whilst the Reynolds number increase results in a smaller recirculation bubble and a shear layer more attached to the bump.
Reynolds Number and Geometry Configuration Effect on Secondary Flows in S-Shaped Circular Bends O. Ayala1*, M.F. Degenring Oliveira2, P. Loures2 1Engineering Technology Department, Old Dominion University, Norfolk VA, USA 2Brazil Scientific Mobility Program, CAPES, Brasilia DF, Brazil *[email protected] Abstract: Numerical simulations of a water flow.
The effects of Reynolds number, Mach number, and gas species (air and CO2) on aerodynamic characteristics of a thin flat plate and a NACA airfoil were investigated under low-Reynolds.
Farnborough facilities provided a Mach number range of to and a Reynolds number capability of to million per foot for these tests. Pressures of to 3 atmospheres were achieved in the variable-pressure facility.
A diagram of the rotary balance apparatus in the low-speed tunnel at Bedford is shown in Figure 1. A five. In order to illuminate the Reynolds number effects from a different point of view, Fig. 6 shows the characteristic diagrams for C d (α), C l (α) and C m (α) against Reynolds number.
Since the measurements for different α were not taken at the same Reynolds numbers, the data were interpolated from the compensating curves displayed in Fig. by: The present study focuses on investigating the persistence of delayed stall for Micro Air Vehicles at Re, The motivation behind present research is to find out the effect of Reynolds number.
The general effect of Reynolds Number on axial flow compressors operating over a sufficiently wide range is described and illustrated by experimental data for four multistage axial compressors.
The wide operating range of military aircraft engines leads in the back stages of high pressure ratio compression systems to three distinctly different regimes of operation, characterized by the boundary Cited by: To simulate the effects of gusts and maneuvers, lift, moment, and flow measurements are presented for a periodically plunging airfoil at a Reynolds number of 20, over a wide range of reduced.
Mach and is interesting as, in this Mach number range, the ﬂ ow regime changes twice, from intermittent shock waves to permanent shock waves and then to wake shock waves, although the.
investigation of the effects of a change in Reynolds number on the flow properties of a rough circular cylinder. To achieve this goal, instantaneous time-dependent aerodynamic forces and mean surface pressure coefficients are obtained with the use of a piezoelectric balance and static surface pressure tabs inside the wind tunnel Size: 5MB.
Ref. Mach number effects were specifically avoided in the experimental work although a wide range of Reynolds number ( × 10 ~ to × l0 s) was covered; tile effects of'compressibility have not, therefore, been considered in the main analysis.
Mach numbers from to for angles of attack from ’ to +18O. Reynolds number varied from million to million based on model base diameter.
Presented are measurements of the normal force, axial force, base pressure, and pitching moment from the static tests, and the damping-in-pitch moment from the dynamic Size: 2MB.
allows for Reynolds number effect simulations with negligible Mach influence as it stays always below The cooling of the air flow, which is necessary at the higher Reynolds numbers, is done by a water film cooling system installed on the outer shell of the tunnel. Cited by: 7. The effects of Mach number ds number on the maximum lift coefficient of a wing of NACA series airfoil- sections are presented.
The ranges of Mach number for the wind-tunnel tests were from to and from to ; the corresponding Reynolds number ranges were from 1, to 4, and from 2,Cited by: 5.
Effect of Reynolds Number on Aerodynamics of the Airfoil without and with Gurney Flap. Computations are carried out for the airfoil without and with a GF of height of 3% chord at six different Reynolds numbers (Re = × 10 5, × 10 5, × 10 5, 8 × 10 4, 5 × 10 4 and 3 × 10 4).Based on the equation for optimum GF given by Traub and Agarwal , the optimum GF height varies Cited by: 2.
The aerodynamic characteristics of rotor airfoils must be assessed at their actual operational Reynolds numbers and Mach numbers. Figure illustrates the operational Reynolds number and Mach number ranges typical of helicopter rotors, both at full scale and model (sub) scale.
The maximum lift coefficient, C/max, can be used as one indicator of the significance of viscous effects. by varying the Reynolds number between 20 and and the freestream Mach number between 0 and The results indicate that compressibility e ects elongate the near wake for cases above and below the critical Reynolds number for two-dimensional ow under shedding.
The wake elongation becomes more pronounced as the Reynolds number. One of the most commonly implemented devices for stall control on wings and airfoils is a leading-edge slat. While functioning of slats at high Reynolds number is well documented, this is not the case at the low Reynolds numbers common for small unmanned aerial vehicles.
Consequently, a low-speed wind tunnel investigation was undertaken to elucidate the performance of a slat at Re = ,Author: Lance W. Traub, Mashaan P. Kaula.Viscous interaction effects are scaled from wind tunnel test data to flight conditions by means of the hypersonic viscous parameter VJ^ discussed earlier: (2) where M = Freestream Mach number CO Rg = Freestream Reynolds number (based on body length, Lg) "Lb C^ = Proportionality factor for the linear viscosity-temperature relationship (Reference.Geometry and Reynolds-Number Scaling on an Iced Business-Jet Wing NASA/TM— August rotary-balance wind tunnel.
Because of the significant reduction in both the geometry and the Reynolds number, the However, the effect of Reynolds number on ice shapes that form far downstream of the leading edge is not as well understood.