PIV Measurements and Computational PIV Measurements and Computational Study Study around a 5-Inch Ducted Fan for VTOL around a 5-Inch Ducted Fan for VTOL UAV UAV Ali Akturk , Akamol Shavalikul & Cengiz Camci 01.05.2009 VLRCOE (Vertical Research Lift Center of Excellence) Turbomachinery Aero-Heat Transfer Laboratory Department of Aerospace Engineering The Pennsylvania State University sented at the 2009 47th AIAA Aerospace Sciences Meeting
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PIV Measurements and Computational Study around a 5-Inch Ducted Fan for VTOL UAV Ali Akturk, Akamol Shavalikul & Cengiz Camci 01.05.2009 VLRCOE (Vertical.
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PIV Measurements and Computational Study PIV Measurements and Computational Study
around a 5-Inch Ducted Fan for VTOL UAVaround a 5-Inch Ducted Fan for VTOL UAV
Ali Akturk , Akamol Shavalikul
&
Cengiz Camci
01.05.2009
VLRCOE (Vertical Research Lift Center of Excellence)Turbomachinery Aero-Heat Transfer Laboratory
Department of Aerospace EngineeringThe Pennsylvania State University
Presented at the 2009 47th AIAA Aerospace Sciences Meeting
Overview
Turbomachinery Aero-Heat Transfer Laboratory
• INTRODUCTION
• OBJECTIVES
• DUCTED FAN MODEL • EXPERIMENTAL SETUP • PARTICLE IMAGE VELOCIMETER (PIV)
• EXPERIMENTAL RESULTS AND DISCUSSION
• THE SPECIFIC ACTUATOR DISK BASED FAN MODEL
• SUMMARY AND CONCLUSIONS
Introduction
Turbomachinery Aero-Heat Transfer Laboratory
NAME OF THE VEHICLE Diameter (inch) Height (inch) Weight (lbs) E. Power (hp)
Hiller flying platform 96 84 180
AROD 52
Skorsky Cypher 74.4 24 240 50
Mass Helispy 11 27 6
Istar 9 12 4 1.2
Dragon-Stalker 200 17
BAE IAV2 22 60 25
Golden Eye- 50 27.5 22.04
Honeywell MAV 13 16 4.2
Univ. of Rome UAV 39.3 200.6 42
DUCTED FAN VTOL VEHICLES
Introduction
Turbomachinery Aero-Heat Transfer Laboratory
• There has been many studies to quantify the flow field properties around ducted fans.
• Martin and Tung tested a ducted fan in hover condition and in forward flight with different crosswind velocities. They have measured aerodynamic loads and performed hot-wire velocity surveys at inner and outer surface of the duct and across the downstream wake .
• Fleming, Jones and Lusardi conduct wind tunnel experiments and computational studies on 12” ducted fan. They have concentrated on ducted fan performance in forward flight.
Introduction
Turbomachinery Aero-Heat Transfer Laboratory
• Graf, Fleming and Wings improved ducted fan forward flight performance with new design leading edge geometry which has been determined to be the significant factor in offsetting the effects of the adverse aerodynamic characteristics.
• Lind, Nathman and Gilchrist carried out a computational study using panel method.
Introduction
Turbomachinery Aero-Heat Transfer Laboratory
•He and Xin developed the ducted fan models based on a nonuniform and unsteady ring vortex formulation for duct and lade element model for fan.
• Zhao and Bil proposed CFD simulation to design and analyze an aerodynamic model of a ducted fan UAV in preliminary design phase with different speeds and angles of attack.
Objectives
Turbomachinery Aero-Heat Transfer Laboratory
• The main aim is to analyze complicated flow field around the ducted fan in hover and horizontal flight conditions is investigated .
• A ducted fan that has a 5” diameter is used for analysis.
• Quantification of velocity field at the inlet and exit of the ducted fan by Planar PIV measurements.
• To generate an efficient definition of fan boundary condition using for actuator disk model.
Ducted Fan Model
Turbomachinery Aero-Heat Transfer Laboratory
Rotor hub diameter 52 mm
Rotor tip diameter 120
Duct inner diameter 126
Blade height h 34
Tip clearance t/h 8.7 %
Max. blade thickness @ tip 1.5
Tailcone diameter 52
Tailcone length 105
HUB MIDSPAN
TIP
Blade inlet angle 1 60 o 40 o 30 o
Blade exit angle 2 30 o 45 o 60 o
Blade chord mm 32 30 28
Design rpm N 13000
Tip Mach number 0.28
Reynolds number(mid-span)
7x104
rtip / RT
Wmc /
Experimental Setup
Turbomachinery Aero-Heat Transfer Laboratory
Cross Wind Blower
NOT TO SCALE
Particle Image Velocimeter (PIV)
Turbomachinery Aero-Heat Transfer Laboratory
PIV Camera
Laser Beam Source
PIV Camera
Calibration plate
Fan Blades
Basic steps of PIV experimental procedure :
• Flow is seeded.• The flow region of interest is illuminated.• Scattering light from the particles forming the speckle images is
recorded by cameras. • Recordings are analyzed by means of correlation software.
In our experiments:
• 80C60 HiSense PIV/PLIF camera
• Nikon Micro-Nikkor 60/2.8 objective
• Double cavity frequency doubled pulsating Nd:YAG laser
• Seeding particles has diameter of 0.25-60 m.
Particle Image Velocimeter (PIV)
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
CCD Camera Laser Head
Laser Sheet
Procedure used in our system :
• Aligning camera and laser sheet.
• The image pairs of PIV domains are recorded.
• The image maps are divided into 32 x 32 pixel interrogation areas and 25% overlapping is used which generated 1748 vectors.
• All the image pairs are adaptive correlated, moving average validated and then ensemble averaged to obtain true mean flow.
• Measurement domains size : [156 mm x 96 mm]
Particle Image Velocimeter (PIV)
Turbomachinery Aero-Heat Transfer Laboratory
PIV Camera
Fan Blades
• The ensemble size is of critical importance in achieving statistically stable mean velocity distributions in SPIV data reduction process.
Particle Image Velocimeter (PIV)
Turbomachinery Aero-Heat Transfer Laboratory
PIV Camera
Particle Image Velocimeter (PIV)
Turbomachinery Aero-Heat Transfer Laboratory
PIV Camera
Fan Blades
Ensemble size of 400 is optimal in achieving a statistically stable average in the current set of experiments.
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
AXIAL VELOCITY CONTOURS
9000 Rpm & 15000 Rpm
@ Hover Condition
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
9000 Rpm
9000 Rpm 15000 Rpm
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
RADIAL VELOCITY CONTOURS
9000 Rpm & 15000 Rpm
@ Forward Flight
LEADINGSIDE
TRAILINGSIDE
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
9000 Rpm
9000 Rpm 15000 Rpm
LEADINGSIDE
TRAILINGSIDE
LEADINGSIDE
TRAILINGSIDE
6.05 m/s
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
VELOCITY MAGNITUDE CONTOURS
&
STREAMLINES
9000 Rpm
@ Hover and Forward Flight
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
9000 Rpm
LEADINGSIDE
TRAILINGSIDE
6.05 m/s
Hover Forward Flight
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
9000 Rpm
Duct Boundary
Drop in axial velocity due to lip separation
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
Fan Blades
VELOCITY MAGNITUDE CONTOURS
&
STREAMLINES
15000 Rpm
@ Hover and Forward Flight
Experimental Results
Turbomachinery Aero-Heat Transfer Laboratory
LEADINGSIDE
TRAILINGSIDE
6.05 m/s
Specific actuator disk based fan model
Turbomachinery Aero-Heat Transfer Laboratory
PIV Camera
Fan Blades
• Incompressible Navier Stokes equations are solved.
•Unstructured computational mesh.
• 700000 tetrahedral cells.
• Symmetry boundary condition is applied at the side surfaces.
• Pressure inlet and outlet boundary conditions are applied at top and bottom.
•Pressure jump boundary condition is applied at the fan surface.