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Saturday, April 25, 2020 | History

3 edition of Effect of blade planform variation on a small-scale hovering rotor found in the catalog.

Effect of blade planform variation on a small-scale hovering rotor

Susan L. Althoff

Effect of blade planform variation on a small-scale hovering rotor

  • 249 Want to read
  • 13 Currently reading

Published by National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division in [Washington, D.C.] .
Written in English

    Subjects:
  • Rotors (Helicopters),
  • Aerodynamics.

  • Edition Notes

    StatementSusan L. Althoff and Kevin W. Noonan.
    SeriesNASA technical memorandum -- 4146., AVSCOM technical memorandum -- 89-B 009.
    ContributionsNoonan, Kevin W., United States. National Aeronautics and Space Administration. Scientific and Technical Information Division.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL14664484M

    Effects of planform geometry on hover performance of a 2-meter-diameter model of a four-bladed rotor / ([Washington, DC]: National Aeronautics and Space Administration, ), by Arthur E. org AVSCOM Phelps, Susan L. org AVSCOM. Althoff, Langley Research Center, United States. Static thrust parameter (units are [(kg^(1/3)/m] versus blade angle for different propellers, having 2, 3, 4, 6, and 8 blades. Given power P and diameter D, an approximation of the thrust T can be calculated. The density of air has been set to kg/m³ (for a description of the coefficients see: aerodynamic characteristics of propellers). An aircraft is a vehicle that is able to fly by gaining support from the counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors and hot air balloons.


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Effect of blade planform variation on a small-scale hovering rotor by Susan L. Althoff Download PDF EPUB FB2

As mentioned before, three of the blade sets had a tapered planform, whereas the fourth blade set Effect of blade planform variation on a small-scale hovering rotor book a baseline rectangular-planform rotor.

The taper ratio for each set of tapered blades was 3 to 1; the difference among the blades was the radial position of the start of the taper. to determine the effects of blade planform variation on the for-ward-flight performance of four small-scale rotors. The rotors were ft in diameter and differed only in blade planform geometrj.

The four planforms were (1) rectangular, (2) linear taper starting at Get this from a library. Effect of blade planform variation on a small-scale hovering rotor. [Susan L Althoff; Kevin W Noonan; United States. National Aeronautics and Space Administration. Scientific and Technical Information Division.].

The data show the 94 percent tapered blade was slightly more efficient at the higher rotor thrust levels. The other tapered planform rotors did not show the expected improvement over the baseline rotor, and all configurations had similar performance for low thrust : Susan L.

Althoff and Kevin W. Noonan. Effect of blade planform variation on a small-scale hovering rotor / By Susan L. Althoff, Kevin W. Noonan and United States. Army Aerostructures Directorate. Abstract. Research done at Aerostrucures Directorate, USAARTA-AVSCOM, Langley Research graphy: p.

Mode of. In connection with the use of twist in blade design, it should be. remembered that negative twist has been found to improve the efficiency. of the rotor in forward flight as well as in hovering and may be.

expected to delay blade stalling at high forward speeds and adverse. compressibility effects at high tip by: to determine the effects of blade planform variation on the forward-flight performance off our small-scale rotors. The rotors were ft in diameter and differed only in blade planform geometry.

The four planforms were (1) rectangular, (2) linear taper starting at 94 percent radius, (3) linear taper starting at 75 percent radius, and. Laminar-turbulent boundary-layer transition is investigated on the suction side of Mach-scaled helicopter rotor blades in climb and analyzed in view of the effect of rotational forces.

number of blades, blade twist, planform taper and winglets at blade tip. Blade airfoil section had a significant impact on the hover efficiency and among the large number of airfoil sections tested, the ones with the lower thickness to chord ratios and moderate camber (% to %) produced the highest rotor hover figure of merit.

Increasing the. It is known from the analysis in Section that blade planform can also have an important effect on the blade lift distribution and, therefore, on the rotor performance.

Usually, small amounts of taper over the blade tip region can help to significantly improve Effect of blade planform variation on a small-scale hovering rotor book figure of merit (FM) in hover. Hover Testing of a Small-Scale Rotor with On-Blade Elevons [Mark V Fulton] on *FREE* shipping on qualifying offers.

Hover Testing of a Small-Scale Rotor with On-Blade Elevons. Integration of dynamic, aerodynamic, and structural optimization of helicopter rotor blades [microform] [The application of experimental data to blade wake interaction noise prediction [microform] / Stewart G Effect of blade planform variation on a small-scale hovering rotor [microform] /.

The hover performance data of full-scale and model-scale coaxial rotors have been compared with CAMRAD II predictions having a free vortex wake analysis.

Performance correlations of a coaxial rotor were made with a variation of key parameters including the rotor spacing and height. This paper describes the systematic performance measurements conducted to understand the role of rotor geometry and blade pitching kinematics on the performance of a microscale cycloidal rotor.

Key geometric parameters that were investigated include rotor radius, blade span, chord, and blade planform.

Because of the flow curvature effects, the cycloidal-rotor performance was a strong Cited by: control surfaces, primarily using small-scale rotor models in conjunc- tion with smart material actuators.

The first design of a bimorph actuator for rotor blade control surface deflection was that of Hall and Soaneler A - (Refs. 16, 17) who conducted a low speed wind tunnel test of a in.

Unmodified blade R Rotor hub Fig. XV rotor blade planform (45¡ twist and 1¡ baseline sweep not shown). The stiffness of the control system has a strong effect on aeroelastic stability.

Previous research (Ref. 6) showed that a large increase in stability was obtained with double the baseline pitch stiffness, but further increases in File Size: KB. the effects of rotor blade flexibility and unbalance on helicopter hovering stability and control [leonard goland] on *free* shipping on qualifying offers.

the effects of rotor blade flexibility and unbalance on helicopter hovering stability and controlAuthor: LEONARD GOLAND. Comparative Performance Measurements of Two Helicopter Blade Profiles in Hovering Flight By M. RILEY AND P. BROTHERHOOD specifically for helicopter rotor blades can effect a better compromise of performance characteristics in the Blade profile characteristics are particularly important in the tip region of a rotor blade since, in.

Introduction. There are two common approaches to blade aerodynamic performance design. First, most researchers now focus on blade shape design to optimize the aerodynamic performance of rotor blades by selecting the point of taper initiation, root chord, taper ratio, and maximum twist which minimize hover power without degrading forward flight performance.

1 This approach usually deals with Cited by: Abstract. The fact that helicopter rotors encounter transonic aerodynamic flow problems has been recognised for several years, and with this realisation there has been considerable activity in recent years in the study of ways of improving rotor performance through blade section and tip design [1–12].Cited by: 1.

Rotary Wing Planform Common terms used to describe the helicopter rotor system are shown here. Although there is some variation in systems between different aircraft, the terms shown are generally accepted by most manufacturers.

The system shown here is fully articulated: Semirigid types do not have a vertical or horizontal hinge pin. Full text of "A study of the effect of design parameter variation on predicted tilt-rotor aircraft other formats NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS u I i A STUDY OF THE EFFECT OF DESIGN PARAMETER VARIATION ON PREDICTED TILT- -ROTOR AIRCRAFT PERFORMANCE by Mary Cottrell Dunston December Thesis Advi sor: Richard D.

This type of tip shape has properties that would also be advantageous on the advancing blade of a helicopter rotor, in that it maintains the sweep and this helps to keep the drag low. These features may also have acceptable high-incidence characteristics for the retreating blade, and should have low drag in by: Rotor Blade RESULTS Figure 4: Total Deflection Of Helicopter Rotor Blade Figure 5: Von Mises Stress Of Helicopter Rotor Blade V.

DYNAMIC ANALYSIS OF HELICOPTER ROTOR BLADE Modal ANALYSIS: Modal Investigation Might Have Been Conveyed Out To Focus The Common Frequencies Furthermore Mode Shapes Of A Structure In The Recurrence Go For 0 - : S Mohan Kumar, J Narsaiah, Pininti Sairam Reddy.

A wide range of kinematic and geometric parameters was systematically varied to study their impact on rotor performance in hover.

The effect of blade kinematics on rotor performance was studied through variation of rotational speed, blade pitching amplitude (symmetric and asymmetric blade pitching), pitching axis location, and blade by: the optimum hovering rotor used on the majority of quadrotors.

Though this rotor is proven to be the most optimum rotor, we show that geometric variations are necessary for manufacturing of the blades. The geometric variations are also dictated by a desired thrust to horizontal force ratio which is based on the available motorCited by: the blade sets had a tapered planform, whereas the and the shaft angle was set to zero.

The flapping of fourth blade set was a baseline rectangular-planform the rotor blades was monitored ad was maintained rotor. The taper ratio for each set of tapered blades less than After the data had been collected for. An Euler or RANS structured approach to numerical simulation of the flow past a hovering rotor poses many challenges for Computational Fluid Dynamics (CFD).

Still, the predictions of Aero-H and Aku-H correspond well with the experimental databases of Caradonna-Tung and by: 3. Modeling a Small-Scale Helicopter for Simulation and Control Development Jared Kevin Cooper Abstract The Virginia Polytechnic Institute and State University has recently expanded its unmanned and autonomous systems research to include aerial vehicles.

In the summer ofmembers of the Autonomous Aerial Vehicle Team at Virginia Tech successfully. Experiments Concerning the Effect of Trailing, Edge Thickness on Blade Loss and Turbine Stage Efficiency but rotor blade thickness effects on efficiency are in line with simple prediction.

Section 1. Introduction a series of stator and rotor blade sections were designed to give progressive variation in trailing-edge thickness. File Size: 1MB. Suggested Citation: "4 WIND TURBINE ROTOR DESIGN ISSUES." National Research Council.

Assessment of Research Needs for Wind Turbine Rotor Materials Technology. Washington, DC: The National Academies Press. doi: / Wind turbine rotor blades are a high-technology product that must be produced at moderate cost for the resulting.

tions [5], [6], [7]. Although an isolated rotor in hover can be cast as a steady-state problem in a non-inertial refer-ence frame, this simpli cation is not general enough for maneuvering ight or multi-rotor vehicles. Actuator disk and blade element rotor models have seen widespread usage for modeling propellers and rotor-airframe interactions.

Start studying ASA Helicopter Airframe. Learn vocabulary, terms, and more with flashcards, games, and other study tools. In a hovering helicopter equipped with a tail rotor, directional control by.

If a severe abnormal vertical vibration developed in a helicopter two blade rotor system, it. Integrated MAV Systems:Hovering: Rotary-Wings & Flapping-Wings Alfred Gessow Rotorcraft Center Planform variation has small effect 5 10 15 20 25 30 35 40 Disk 2Loading [N/m ] P o w e r L o a d i n g [N / W] Shrouded Rotor Wake: Effect of Blade Tip Clearance ddd tip = % d tip = % d tip = % Isolated rotor.

Effect of the overlap ratio on the rotor rotation speed. Figure Effect of overlap ratio on power coefficient. Effect of blade shape factor The second test looks for the effect of blade shape factor on turbine performance. The modified Savonius rotor is constructed with an overlap ratioand a blade arc angle 90°.

Variations of the. Size Scale Rotor Blades. Sort by: BELL SIZE CF MAIN ROTOR BLADE. Your Price: Price: $ Size AH-1 Cobra CF Main Rotor Blade. Your Price: Price: $ MM Scale Carbon Fiber Blade Set for Superscale - MD black. Your Price: Price: $ mm Size Scale Blades for use on our Roban Bell EFFECTS OF BLADE TIP SHAPE ON ROTOR IN-GROUND-EFFECT AERODYNAMICS.

View measurements were conducted to examine the wake produced by a hovering single-bladed rotor as it interacted with a horizontal ground plane. The results showed that the wake was subjected to powerful curvature and straining effects as it interacted with the ground Cited by: 1.

The Evolution of Rotor and Blade Design July Ł NREL/CP James L. Tangler Presented at the American Wind Energy Association WindPower Palm Springs, California April 30ŒMay 4, National Renewable Energy Laboratory Cole Boulevard Golden, Colorado NREL is a U.S.

Department of Energy LaboratoryFile Size: KB. I would appreciate some feedback on a very small hovering airframe using coaxial fixed blade rotors (no cyclic or collective) powered by brushless motors.

Props will be in the range of " diameter, with total aircraft height of less than 8", and total weight, including electronics and battery less than 9-oz (gm). A cyclorotor, cycloidal rotor, cycloidal propeller or cyclogiro, is a fluid propulsion device that converts shaft power into the acceleration of a fluid using a rotating axis perpendicular to the direction of fluid uses several blades with a spanwise axis parallel to the axis of rotation and perpendicular to the direction of fluid motion.

These blades are cyclically pitched twice per. Understanding the Effect of Blade Flexibility on Cycloidal Rotor Performance in Hover Authors / Details: Atanu Halder and Moble Benedict (Texas A & M University) Recently Viewed Items.Systematic Analysis of Rotor Blade Effective Twist Due to Planform Variation (76) Fu-Shang (John) Wei, Central Connecticut State U.

and David A. Peters, Washington University, St Louis. Paper # 2– – a.m. Development of Rotor Structural Design Optimization Framework for Compound Rotorcraft with a Lift Offset (53).isolated rotor blade by solving the NavierStokes equations using the MRF method.

Table 1 Characteristics of the test bed (AgroHeli-4G) Parameters Symbols Values Number of blades N b 2 Rotor blade radius R m Blade chord length c m Nominal rotor speed Ω rpm Blade tip Mach number tip M Blade aspect ratio AR Rotor solidity Cited by: 3.