The angles of the fact rotor tipvanes on the rods and on the blades

Report IW-R516

,

The Angles of the Fact Rotor

ISBN 90-6275-522-4

.)1

Tipvanes on the Rods and on the

. \

Blades

November 1988 A. Bruining

~

1f

T

U

Delft

Institute of Windenergy Delft University of Technology

A. Bruining

20

\

0

Delft University Press,

1988

Bibliotheek TU Delft

1111111111 111

C 1706377

Stevinweg 1 2628cN Delft The Netherlands By order of:

Delft University of Technology Institute for Windenergy

Kluyverweg 1 2629HS Delft The Netherlands Report IW-R516 November 1988

Carried out within the Dutch Development Program for Wind Energy (NOW-2); by order of the Management Office for Energy Research PEO; financed by the Ministry of Economic Affairs.

elP-GEGEVENS KONINKLIJKE BIBLIOTHEEK, DEN HAAG Bruining, A.

The angles of the fact rotor tipvanes on the rods and on the blades / A. Bruining. - Delft : Delft University Press. - 111., fig., tab.

Report IW-R516. - Carried out within the Dutch Development Program for Wind Energy (NOW-2); by order of the

Management Office for Energy Research PEO and by order of Delft University of Technology: Institute for Windenergy. ISBN 90-6275-522-4

SISO 653.2 UDC 533:621.548 NUGI 834 trefw.: windenergie; aêrodynamica. copyright~by Delft University Press.

No part of this book may be reproduced in any form by print, photoprint, microfilm or any other means, without written permission from Delft University Press.

Contents

Summary

1. Symbols 2. :nt~oduction

3· Tests, methods and procedures

3.1 Measurement angles and aerodynamic angles 3.2 Methods

3.2.1 Liebeck tipvanes on the rods

3.2.2 NACA tipvanes on the rods 3.2·3 NACA tipvanes on the blades

3.3

Accuracy

4.

Results

5.

References Tables Figures pag.

3

4 7 8 8 9 9 10 11 12 13

14

15

29

Summary

This report contains the data of the angles of the tipvanes of the FA CT rotor. These tipvanes were used on the FACT rotor blades and rods.

Two sets uf tipvanes wel'e IUeasured: a set having a Liebeck air-foil section and a set with a NACA airfoil section.

The tipvanes with the Liebeck airfoil section were mounted on the rods only. The tipvanes 'with the NACA airfoil section were mounted on both the rods and the FACT rotor blades.

For the measurements on the rods the Liebeck tipvanes were adjusted to

5

different positions of the incidence angle and the NACA

tipvanes were adjusted to 6 different positions of the incidence angle.

The applied measuring method was based on determining the chord vector and the span wise vector of the tipvane for 1 or sometimes 2 incidence settings.

The aerodynamic angles of the tipvanes for the other incidence angle settings were calculated from this one incidence angle setting and from the measured differences of the actual incidence angle for the other settings

The NACA tipvanes, mounted on the FACT rotor blades, could not be adjusted, only the tipvanes mounted on the rods were adjustable. The theoretical background of the different angle systems, used to define the attitude of the tipvane in the 3-dimensional space and measuring procedure is not included in this report, but is explained in ref. 1.

1. Symbols e Q r R vb h or vb vert vc vert y AQ AVC h or

displacement of the 8-hinge to the rotor shaft, see fig.

4

(=

3.1

m) FACT ,:otor blade length local radius

rotor tip radius

tipvane measurement angle, defined in section

3.1

tipvane measurement angle, defined in section

3.1

tipvane measurement angle, defined in section

3.1

tipvane measurement angle, defined in section

3.1

flapping angle

tilt angle of the tipvane

displacement of the tipvane due to the wagging effect, see fig. 3

difference in the tipvane measurement angle vC

h or ,denotes accuracy, see section

7.3

of ref. 1

(m) (m) (m) (m) (degrees) (degrees) (degrees) (degrees) (degrees) (degrees) ( m) (degrees)

e: e:blade 6 9 blade root 9 . correct~on 9 edge 9 _nom~na . 1 6

r=1·5

9

r=3

.

9

change of the incidence angle, see fig. 3

measured blade twist angle, based on the blade length Q = 3.1 m

blade twist angle of 1 blade, averaged of 2 measurements, based on blade length Q = 3.1 m

incidence angle of the tipvane

blade pitch angle at the blade root

r

= 1.

375 m

(=

~

*

180) correction of the

R n

incidence angle of the tipvane due to shifting of the tipvane

tipvane angle of the construction type between the edge of the mounting part and the centre line of the originally holes in the mounting part, defined in fig.

4

indication of the designed tipvane incidence angle

measured blade pitch angle at

r = 1.5 m

measured blade pitch angle at

r

=

3.9 m

(degrees) (degrees) (degrees) (degrees) (degrees) (degrees) (degrees) (degrees) (degrees) (degrees)

a

_ref

A

indices

a

c

reference p~tch angle of the blade or rad, measured at the root mounting part

blade pitch angle at the rotor blade tip

sweep angle of the tipvane

offset angle, of the tipvane, defined in fig. 2

indicates the aerodynamic angles

indicates the construction angles

indicates flapping angles

(degrees)

(degrees)

(degrees)

2. Introduction

For the measurements of the drag of the NACA and Liebeck tipvanes on

the FACT (Flexible Advanced Composite Tipvane) rotor

4

sets of

mounting parts were originally manufactured. The various mounting

parts results into different lift coefficients for the tipvctne~. In

that way it is possible to determine the tipvane drag as a function

of the tipvane lift.

Only 1 set of mounting parts was usabIe. The other parts did not fit very weIl in the tipvanes.

The problem to achieve the necessary different lift settings was

solved by milling a slot and drilling

4

wholes for davel pins. By

using a davel pin through the mounting part and the rod different settings could be established.

At the same time the original incidence angle

e

had to be corrected,

because the built-in angle in the tipvane was too high. During the manufacturing phase of the tipvane the Euler sequence of the tilt angle and sweep angle was interchanged. This gave the tipvane a

higher angle of attack in the order of

4

degrees than in ~ded.

Because the tipvanes fits directly in the rotor blade, a correction of the too high angle of attack was only pos si bIe for the tipvanes mounted on the rods. Applications of the tipvanes on the rods was mainly carried out for the drag measurements.

3.

Tests, methods and procedures

3.1 Measurement angles and aerodynamic angles

vb_{h or} ,vc_{h or} ; vb _ver t and vc _ver t are called the measurement angles. They are defined as follows.

The line from the

~

chord point of the tipvane at the mounting part towards the rotor shaft is positioned exactly horizontal. The angle between the vertical vector v and the span vector b is then called

vb

h or . The angle between v and the chord vector c is vC_{1 or} h . The same angles are measured once again with the line from the

2

chord point of the tipvane at the mounting part now positioned exactly vertical. These angles are denoted vb _ver t and vc _ver t respectively. See fig. 1. The angles of the Liebeck and NACA tipvanes were measured by the method described in section 7.2 of ref. 1 for the tipvanes on the rods, and according to section

7.4

of ref. 1 for the NACA tipvanes on the blades. These angles are denoted as the measurement angles in this report and the other related publications.

From these measurement angles the aerodynamic angles can be

calculated directly with the formulae given in section

7.3

of ref. 1. The correct ion for the flapping angle ~ was made with the

formulae of section

6.3

of ref. 1.

The flapping angles were estimated from the displacement of the tipvane on a television screen, which showed the picture taken with a rotating television camera. The television camera was mounted quite close to the hub.

3.2 Methods

3.2.1 Liebeck tipvanes on the rods

Only for one e setting, e . 1 = 10°, the measurement angles of nom1na

the Liebeck tipvan~ X and the Liebeck tipvane Y of tne FACT rotor were determined to reduce the measurement work. Next the aerodynamic angles were directly calculated.

For the other

4

settings of e the aerodynamic angles were calculated from the change in e . For this purpose the aerodynamic angles were

c

transformed to the construction angles with the formulae given in section 6.2.1 of ref. 1.

At

a

.

= 10° the tipvane is moved backwards a little. This give nom1nal

a small increase in the angle of attack. To correct for this effect

a

_{c must be increased byecorrection (see fig.}

3).

Af ter this the measured change in e was added. The change in e

c c

corresponds directly with the change in

a

d which was in fact e ge

measured.

a

_{e ge} d is defined in fig.

4.

a

_{e ge} d is an angle of the construction type and is defined as the angle between the edge of the mounting part and centre line of the two originally holes. Again a second correction was made for the wagging effect according to section 8 of r .. 1.

So the new incidence angle

a

was calculated from the old one at c

e

_nom1na

.

1 = 10° by:

a

c new +

Aa

c AQ R

*

Aa

c

Af ter this the new construction angles were transformed back to the aerodynamic angles.

Finally a correction for the flapping angle ~t_1pvane ' = 1° was made and the results of tipvane X and tipvane Y were averaged because all measurements and calculations were done for each tipvane separately. The step via the construction angles is necessary because the

mounting parts rotates in aplane perpendicular to the X-axis, see fig.

5

and fig.

6

(see also ref. i, section

4.2),

and not in aplane perpendicular the chord vector of the tipvane.

3.2.2 NACA tipvanes on the rods

The mounting parts of the NACA tipvanes were adjusted to 6 positions.

For all adjustments the measurements angles were determined and the aerodynamic angles were calculated directly with the formulae of section

7.3

of ref. 1.

A correction was included for the wagging effect by using the angle

W.

The angle w is introduced because the a-hinge is

0.15

m displaced to the rotor shaft, so a a change will also give the tipvane a

displacement dQ, see section 8 of ref. 1. W was calculated by:

w

= arcsin {~ * sin (a

edge)}

with e

=

0.15

m, the displacement of the ah" and R

=

4.475

m, the ~nge

rotor radius.

The distance is indicated in fig.

4.

Finally the flapping angle ~ =

1°

was added and the results of tipvane

3

and tipvane

4

averaged, because all measurements and calculations were carried out for each blade separately.

Only for tipvane

4

at a "

=

0

0 _{and a "}

₌

_16°

_{a small A}

nom~nal nom~nal a

correction was made by an increase of a f befare averaging to re

eliminate a small sweep angle difference between tipvane

3

and tipvane

4.

The drag of the tipvane was also measured at two other sweep angle settings at anominal = 2, 6, 10 and 14°. The pitch of the rods that corresponds with these two sweep angle settings was a f _re =

-4.7°

and a f = +4.7°. The sweep angle change was directly calculated by:

re

A = A + da f'

a~ a~ re

This is not quite correct due to the flapping angle, but the mis take is very small because ~ is very small.

3.2.3 NACA tipvanes on the bl~des

Two blade pitch settings were used for the performance measurements of the FA CT rotor.

At two radii the blade pitch was determined: r = 1.5 m and r = 3.9

ID.

The flexbeam was put exactly horizontal. At the low pitch adjustment blade 1 was measured twice, whereas at the high pitch adjustment blade 2 was measured twice. At the second measurement the rotor was rotated over 180 degrees with respect to the first measurement. The blade twist ~ is based on the blade length Q = 3.1 m.

~ was calculated with:

~ =

8 -8

r=1.5 r=3·9

*

3.1 3.9-1.5

and averaged for each blade separately, which gives ~blade. 8tip and 8blade root follow from:

and

8 . = 8

tlp r=3.9 - ~blade

*

(R-3.9)/3.1

8blade root = 8tiP + ~ blade

Also 8 _re f' the pitch angle of the flexbeam, was registrated for each blade separately of both blade pitch settings. With this value the

A of each tipvane was corrected separately. a

The tipvane measurement angles were determined for 8 f = O. From re

these measurement angles the aerodynamic angles were calculated with the formulae of section

7.4

of ref. 1 (~ = 0) and A was corrected

a

with:

A A + 8

a a ref

Af ter this the aerodynamic tipvane angles were corrected for the flapping angle ~=5° using the formulae of section 6.3.

Finally the tipvane angles of tipvane 3 and tipvane 4 and the blade pitch angles of blade 1 and blade 2 were averaged.

3.3 Accuracy

The accuracy of the blade pitch angles is in o~der öf ! 0.25° due to read errors and the not really flat surface of the measurement

plane.

A flap or lag movement of the rod did not introduce a twist in the rod due to coupling effects in the flexbeam, so there was no sweep angle correction necessary.

A force of 200 N in lag direction at the tip gives a rod rotation in the order of 0.75° to 10 _{when the rotor shaft in fixed. The change}

in

e

of the tipvane is smaller because the centre of this rotation a

is quite close to the rotor shaft.

In the calculations of

e

this effect was neglected. The margin in

a

torsion direction is in the order of 1° due to limited stiffness.

The order of accuracy of the tipvarie measurement angles is 0.50 •

àVC

4

.

Results

Table 1 and table 2 gives the original measurement angles and calculated aerodynamic angles of tipvane X and tipvane Y with a

Liebeck 5055 airfoil, and tipvane 3 and tipvane

4

with a NACA 23012 aicfuil respectively of the FACT rotor bafore milling a slot in the mounting part. The tables show clearly the rather high values for 8 a

which give the tipvane an angle of attack in the stall region. It is too high for optimal opèration of the tipvane.

Table

3

through table 5 give the measurement angles and the

calculated aerodynamic angles of the Liebeck tipvanes mounted on the rods af ter the slot was milled in the mounting parts.

Only for one incidence angle setting the measurement angles were determined and the aerodynamic angles calculated directly. For the other incidence angles the aerodynamic angles were calculated from that measured one by using the measured

a

change. Only at table 5

c

the results were averaged of tipvane X and tipvane Y. Aflapping angle ~=1° was used.

Table 6 through table 8 give the results of the measurement and calculated aerodynamic angles of tipvane 3 and tipvane

4

of the FACT rotor, mounted on the rod. Also aflapping angle ~=1° was used. The measurement angles were only

8 . I adjustments, except for nomlna

a

.

I = 160 _where

a

_{f = 1.3}0

nomlna re

determined for

a

f = 0 for all re

tipvane

4

at 8 . I = 00 _and

nomlna (see table 6b).

The sweep angle A at 8 f

=

-4.7

0 _{and 8}

=

_+4.7

0 _{were directly}

a re ref

calculated from 8

ref = 00 • Only table 8 gives the averaged results of both tipvanes.

Table 9a gives the measured blade pitch angles. Table 9b gives the calculated blade pitch angles and twist for each blade separately. Which values for the calculations were used is indicated in the

footnotes of table 9b.

Table 10 gives the measurement angles and the calculated aerodynamic angles for each tipvane separately mounted on the blade.

Table lOc is corrected for

a

f ~ 00 •

re

Table 11 finally gives the averaged results of the blade twist and pitch angle and aerodynamic tipvane angles. Aflapping angle ~ = 50

5. References

1. A. Bruining

2. A. Bruining

3.

A. Bruining

Definition. transformation-formulae and measurements of tipvane angles.

IW-R510. 1987. ISBN 90-6275-424-4.

Performance measurements of the

Kolibrie and FACT rotor with tipvanes on the full scale experimental wind turbine. IW-R519. 1988.

Tipvane drag measurements on the full-scale experimental wind turbine. IW-R517. 1986.

tipvane tipvane X tipvane Y

airfoil section Liebeck

5055

Liebeck

5055

9 ref degrees

0

0

vb vert degrees

75.75

75·25

vc vert degrees

74.75

76.33

vb h or degrees

81.67

82.33

vC_hor degrees

163.33

165.17

vC h or degrees

0.75

0.53

A _a degrees

8.60

7.93

r _a degrees

14.25

14.75

9 _a degrees

15.75

14.14

Table 1: The original measurement angles of the Liebeck tipvane of the FACT rotor on the rods mounted, and the matched

aerodynamic angles (before milling the slot in the mounting part) .

tipvane tipvane

3

tipvane

4

airfoil section NACA

23012

NACA

23012

8 ref degrees

0

0

vb vert degrees

75.58

75.50

vc vert degrees

70.75

71.67

vb hor degrees

80.67

81.92

vC hor degrees

159.58

160.75

AVC h or degrees

0.55

0.61

A degrees

_9.64

_8.34

a r degrees a

14.42

14.50

8 _a degrees

_19.90

_18.96

Table 2: The original measurement angles of the NACA tipvanes of the FA CT rotor on the rods mounted. and the matched aerodynamic angles. before milling the slot in the mounting part.

tipvane tipvane X tipvane Y

airfoil section Liebeck 5055 Liebeck 5055

-8 ref degrees 0 0 8 nominal degrees 10 10 vb vert degrees 75.0 74.5 vc vert degrees 83.67 83.5 vb h or degrees 83.17 83.5 vC hor degrees 172.25 172.92 AVC h or degrees -0.55 -1.1 8 edge degrees -10·33 -8.67 A8 _wag degrees 0.35 0.30

Table 3a: Measurement angles of the Liebeck tipvanes of the FACT rotor af ter manufacturing the slot in the mounting parts.

tipvane X tipvane Y

9

nominal 9 edge d9 c 9 edge d9 c

degrees degrees degrees degrees degrees

2 -18.75 -8.07 -17.08 -8.11

6 -14.67 -3.99 -13.16 -4.19

101 ) -10.33 0.35 -8.67 0.30

14 -16.33 4.35 -4.75 4.22

18 -2.08 8.60 -0.50 8.47

1) angle for which the measurement angles were determined.

Table 3b: The change in 9 of the mounting parts of the 5 possible 9

c

Tipvane X Liebeck 5055 airfoil

e

_ref degrees 0 0 0 0 0

e

nominal degrees 2 6 10 14 18

e

_c degrees -1.44 2.50 6.70 10.57 14.67 ~

=

00 _{A degrees} 5.34 5.34 5.34 5.34 5.34 c y _{degrees 15.69 15.67 15.69 15.69 15.69} c A degrees 4.93 6.03 7.17 8.17 9.19 a f>

=

00 _{y degrees 15.82 15.44 14.96 14.44 13.82} a

e

degrees -1.49 2.59 6.91 10.87 15.05 a A degrees 4.91 6.00 7.13 8.14 9.16 af> f>

=

p y degrees 14.82 14.45 13·97 13.45 12.83 a~

e

degrees -1.58 2.48 6.78 10.72 14.89 af>

Table 4a: Calculated values of the construction angles and aerodynamic angles of tipvane X of the FACT rotor with Liebeck airfoil mounted on the rod.

Tipvane Y Liebeck 5055 airfoil

a

_ref degrees 0 0 0 0 0 r---- .-

_

.

-8 nominal degrees 2 6 10 14 18

a

_c degrees -1. 31 2.47 6.81 10.60 14.71 f3 = 00 _{/I. degrees 4.90 4.90} 4.90 4.90 4.90 c '( degrees _16.16 c 16.16 16.16 16.16 16.16 /I. degrees 4.52 _{5.61 6.83 7.85 8.91} a f3 = 00 '( _{degrees 16.27 15.94 15.47 14.98 14.38} a 8 _a degrees -1.36 2.57 7.05 10.94 15.14 A degrees 4.50 5.59 6.79 7.81 8.88 af3 f3 = 10 '( degrees _{15.27 14.94 14.47 13.99 13.39} af3 8 degrees -1.45 af?> 2.46 6.92 10.80 14.98

Table 4b: Calculated values of the construction angles and aerodynamic angles of tipvane Y of the FACT rotor with Liebeck airfoil mounted on the rod.

8 nominal degrees 2 6 10 14 A degrees 4.71 5.80 6.96 7.98 a~ ~ = 10 '( degrees _{15.05 14.70 14.22 13·72} a~ 8 degrees -1.52 2.47 6.85 10.76 af)

Table 5: Adjusted angles of the Liebeck tipvanes of the FACT rotor mounted on the rods (average of table 4a and table 4b) for R> = 10

•

Tipvane 3 NACA 23012 airfoil 8 ref degrees 0 0 0 0 0 8 nominal degrees 0 2 6 10 14 vb _vert degrees 74.17 74.58 74.75 75.33 75.42 vc vert degrees 90.08 89.67 85.67 81.33 77 .83 vb h or degrees 85.58 85.58 84.42 85.00 82.08 vC hor degrees 175.58 175.50 174.00 170.75 167.67 t.vc h or degrees -0.20 -0.00 -0·32 -0.12 -0.79 1\1 degrees -0.56 -0.54 -0.42 -0.26 -0.14 8 edge degrees -17 .00 -16.25 -12.50 -7.75 -4.33

Table 6a: The measurement angles of tipvane 3 of the FA CT rotor mounted on the rod.

18 9.02 13.11 14.94 0 16 75·75 76.08 81.67 165.42 -0.18 -0.08 -2.25

Tipvane 4 NACA 23012 airfoil 8 ref degrees + 1. 31 ) 0 0 0 0 +1. 31 ) 8 nominal degrees 0 2 6 10 14 16 vb vert degrees 74.25 74.50 74.42 75.25 75.50 75.42 vc vert degrees 89.33 88.50 85.00 81.00 77 .00 74.67 vb h or degrees 85.00 86.58 85.50 84.08 83.25 81.00 vC hor degrees 174.58 176.00 174.00 170.58 166.75 164.25 tovc h or degrees 0.37 0.53 0.03 -0.32 -0.22 -0.43 1\1 degrees -0.53 -0.50 -0.38 -0.24 -0.11 -0.04 8 edge degrees -16.08 -15.17 -11. 33 -7.25 -3.25 -1.25 1) A small pitch correction was made to eliminate a small sweep angle difference between tipvane

3

and tipvane 4.

Table 6b: The measurement angles of tipvane 4 of the FACT rotor, mounted on the rod.

Tipvane 3 NACA 23012 airfoil 9 nominal degrees 0 2 6 10 14 A _a degrees 4·.75 4.73 5.90 5.24 8.22 R>

=

0° r _a degrees 15.79 15·37 15.21 14.64 14.56 8 _a degrees 0.50 0.90 4.92 9.23 12.73 A degrees 4.73 4.71 5.87 5.21 8.18 ~ R>

=

1° r degrees 14.79 14.38 14.21 13.65 13.57 aR> 9 degrees 0.41 0.82 4.81 9.13 12.58 aR>

Table 7a: Aerodynamic angles without and with flapping angle f3 of tipvane 3 of the FACT rotor mounted on the rod.

Calculation based on the values of table 6a.

Tipvane 4 NACA 23012 airfoil

9 nominal degrees 0 2 6 10 14 A degrees 5.34 3.68 4.78 6.18 7.00 a R> = 0° r degrees a 15·70 15.47 15·55 14.72 14.49 9 degrees 1.24 2.08 5.58 9.56 13.55 a A degrees 5.32 ~ 3.67 4.75 6.16 6.97 f3 = 1° r degrees af3 14.71 14.47 14.56 13·73 13.49

e

degrees 1.15 a~ 2.01 5.50 9.45 13.42

Table 7b: Aerodynamic angles without and with flapping angle f3 of

tipvane 4 of the FA CT rotor mounted on the rod. Calculation based on the values of table 6b.

16 8.(2 14.24 14.44 8.58 13.25 14.29 16 9·31 14.58 15.90 9.27 13·59 15.73

0 0 0 8 nominal ~ = 1 ~ = 1 ~ = 1 0 0 0 8 _ref = 0 8 _ref = -4.7 8 = +4.7 ref A '( _{8 A} '( _{8 A} '( ₈ a~ a~ a~ a~ a~ a~ a~ a~ a~ I

degrees degrees degrees degrees

2 4.19 14.43 1.42 -0.51 14.43 1.42 8.89 14.43 1.42 6 5.31 14.39 5.16 0.61 14.39 5.16 10.01 14.39 5.16 10 5.69 13.69 9.29 0.99 13.69 9.29 10.39 13.69 9.29 14 7.58 13.53 13.00 2.88 13.53 13.00 12.28 13.53 13.00 0 5.03 14.75 0.78 16 8.93 13.42 15·01

Table 8: Resulting aerodynamic angles of the NACA tipvanes of the FACT rotor, corrected values for the flapping angle, of the drag measurements on the rods on the field test installation in Hoek van Holland (average of table 7a and table 7b).

low pitch high pitch

blade 1 blade 2 blade 1 blade 2

ie _{meas. 2}e _{meas. 1 meas.} e _{1 meas.} e ie _{meas. 2}e _meas.

8 ref degrees 0.58 -0.67 4.17 5.67 8 r=1.5m degrees 9.5 12.17 14 13.9 8 r=3.9m degrees 2.6 3.3 1.8 6.25 8.67 8.3 e: 1) _{degrees 8.0 7.6 6.9 7.2} 1) based on Q = 3.1 m

Table 9a: The measured blade pitch angles of the 2 FACT rotor blades at r = 1.5 m and r = 3.9 m. 8 ref e: blade 8 tip 8 blade

The 2e measurement indicates a rotation of 180 degrees of the rotor. The skipped values were unreliable or not measured. The blade twist e: is based on the blade length of 3.1 m.

low blade pitch high blade pitch

blade 1 blade 2 blade 1 blade 2

degrees 0.58 -0.67 4.17 5.67

degrees 7.8 7.1 7.8 7.1

degrees 1.15 1 ) 0.48 2 ) 4.8 3 ) _7.35 ~ )

degrees 9.0 7.6 12.6 14.5

root

1 ) calculated with e:blade = 7.80 and 8 = 2.60

r=3·9m

2 ) calculated with e:blade = 7.10 and _{8 =} 1.8

0 r=3.9m 3 ) calculated with e: = 7.8 0 and 8 = 6.250 blade r=3.9m ~ ) _{calculated with e: = 7.1}0 and 8 = 8.670 blade r=3.9m

Table 9b: The calculated twist and blade pitch setting of the 2 FA CT rotor blades separately.

.'

blade 1 + tipvane 3 _{blade 2} + tipvane 4 airfoil tipvane NACA 23012 NACA 23012

~--e

ref degrees 0 0 vb vert degrees 60.42 60.67 vc vert degrees 74.33 73.83 vb h or degrees 82.75 81.42 vC hor degrees 164.33 163.33 ~vch _or degrees -0.02 0.49

Table 10a: The measurement angles of the NACA tipvane 3 and NACA tipvane 4 of the FA CT rotor.

blade 1 + tipvane 3 blade 2 + tipvane 4

airfoil tipvane NACA 23012 NACA 23012

e

ref degrees 0 0 A degrees 8.34 9.86 a y _{degrees 29.58 29.33} a 8 degrees 18.09 18.63 a 8 degrees 15.67 16.17 C A degrees -0.79 0.46 C Y degrees 30.63 30.8 c

Table lOb: The calculated aerodynamic angles and construction angles of the NACA tipvane of the PACT rotor, for each tipvane separately. Based on the measurement angles of table 10a.

low blade pitch high blade pitch

airfoil tipvane NACA 23012 NACA 23012

blade 1 + blade 2 + blade 1 + blade 2 +

tipvane ₃ tipvane 4 tipvane 3 tipvane 4

8 ref degrees 0.58 -0.67 4.17 5.67 A degrees 9.16 a 9.19 12.51 15.53 y _~

₌

_{0° degrees 29.58 29·33 29.58 29.33} a 8 degrees 18.09 18.63 18.09 18.63 a A degrees 8.76 8.79 11.97 14.86 a~ y _~

₌

_{5° degrees 24.64 24.39 24.69 24.50} a~ 8 degrees 17.21 17.75 16.90 17.16 a~

Table lOc: The aerodynamic tipvane angles without and with aflapping angle ~ corrected for 8 f

F

0 for each blade separately.

low blade pitch high blade pitch airfoil tipvane NACA 23012 NACA 23012

average of average of table lOc table lOc

Stip degrees 0.8 6.1

rotor blade c degrees _{7·5 7.5}

S

blade root degrees 8.3 13.6

A degrees 8.78 13.42 a~ tipvane '( _{~ = 5}0 _{degrees 24.52 24.60} a~ S degrees 17.48 17.03 a~

Table 11: The ave rage values of the blade pitch angles of the FACT rotor (tabIe 9b) and NACA tipvanes with flapping angle of

5

degrees .

l

Fig. 1

v

rotational diredion

~

.

\

_{rotor axis llne}

( b

•

v

The horizontal and vertical position of the tipvane for measuring the tipvane angles.

'!..

= j

_-

sin

4> -k

cos

4>

-rotional diredion

~--~---~-~

----~~~~

_rod

k

I

l

_c

~=

1

cos~t ~

si n

~

_____

J

A

wind di

rection

•

Fig. 2 Vector ~ and angle ~ with a ti~vane offset.

di rections of local

~

CV

flow at tipvane

=====[::::::>-

CD CD

.

~

I

180

9correctlon

=

"*

-R

TL

Fig. 3 The wagging effect of the tipvane if the

e

"hinge" is moved to the rotor shaft.

Fig. 4

--

'

.--'

--

>

Ncee 23012 or lieb.eek 5055 tipvene

originally hol.s

slot

The

e

correction of the tipvane mounting part of the FACT c

Fig. 5

1.

1

cos Sc

k

Rotation of the first angle

e

of the construct ion tipvane c

Ijl

.f. cos

"c

*

c

Fig. 6: The vectors of the local tipvane coordinate system in the

.

*