Full Scale Wind Tunnel Tests on Hang Glider Pilots

Cranfield

April 1984

6 mi 1984

TECHWISCHE HOGESCHOOL DELFT

LUCHTVAART- feN RU'.MTtVAAr,nECHII« B I B L I O T H E E K

Full Scale Wind Tunnel Kluyverweg 1 " DEtfT Tests on Hang Glider Pilots

by E.A. Kilkenny

Department of Aerodynamics College of Aeronautics Cranfield Institute of Technology

Cranfield

College of Aeronautics Report 8416 April 1984

Full Scale Wind Tunnel Tests on Hang Glider Pilots

by E.A. Kilkenny

Department of Aerodynamics College of Aeronautics Cranfield Institute of Technology

Cranfield, Bedford, UK.

ISBN 0 902937 99 5

£7.50

"The views expressed herein are those of the authors alone and do not necessarily represent those of the Institute. "

Summary

The weight shift control of hang gliders and the position of the pilot makes the aerodynamic characteristics of hang glider pilots an integral part of hang glider stability and performance calculations. Full scale mobile facilities have been developed to measure the characteristics of the wings but very little information is available about the pilot.

A series of full scale wind tunnel measurements have been carried out to investigate the aerodynamic characteristics of hang glider pilots. Five pilots were tested over a range of positions and wind speeds with various types of pilots harnesses.

The results are strongly dependent on each pilot and the flying position he adopts. They suggest that a range of pilot drag figures should be used in stability calculations rather than just one mean value.

Acknowledgements

I should like to express my sincere thanks to pilots; Mr. Dave Bedding, Mrs. Sandra Edwards, Mr. Dave Harrison, Mr. Clive Leach and Mr. Terry Prendergast for participating

in these wind tunnel experiments and without whose help this work would not have been possible. My thanks also to

Mr. Bill Brookes for the loan of his stirrup harness.

Financial support for this programme was supplied by The Science and Engineering Research Council Grant GR/B/94953.

Acknowledgements

I should like to express my sincere thanks to pilots; Mr. Dave Bedding, Mrs. Sandra Edwards, Mr. Dave Harrison, Mr. Clive Leach and Mr. Terry Prendergast for participating

in these wind tunnel experiments and without whose help this work would not have been possible. My thanks also to

Mr. Bill Brookes for the loan of his stirrup harness.

Financial support for this programme was supplied by The Science and Engineering Research Council Grant GR/B/94953.

Contents Page Summary Acknowledgements Contents List of Tables List of Figures Introduction 1 Chapter 1 - Experimental Procedure 2

Chapter 2 - Experimental Results 4 Chapter 3 - Comparison with other work 7

Conclusions 10 References

Appendix A - Effect of A Frame Size on Drag Measurements

Appendix B - Wind Tunnel Interference Corrections Tables

List of Tables

1. Mean Drag Area of each Configuration Tested 2. Repeatability of Measurements

3. Drag Area of the A Frame

4. Mean Drag Area of each Configuration Tested (A Frame Drag Subtracted)

5. A Typical Breakdown of the Total Drag of a Hang Glider and Pilot in Flight

6. Drag Area of an Average Man in Various Positions 7. Results Obtained in the BMW Wind Tunnel in Munich 8. Results Obtained in the Eiffel Wind Tunnel in Paris 9. Results Obtained at the Institute for Aerodynamics in

List of Figures

1. The British Hang Gliding Association's Mobile Aerodynamic Test Facility

2. Schematic Arrangement of the A Frame and Pilot Fittings to the Wind Tunnel

3a,b. Pilot Position to Simulate 'Pulling on Speed' 4a,b. Pilot Position to Simulate Typical Trim Condition 5a,b. Pilot Position to Simulate Pushing Out on Bar

6a,b. Pilot Position to Simulate Pushing Out on Bar - Chest Raised

7a,b. Pilot Position to Simulate 'Gorilla' Position 8a-h. Variation of Drag Area with Pilot's Position 9a-d. Repeatability of Drag Measurements

lOa-d. Variation of Drag Area with Pilot

lla-c. Variation of Drag Area with Pilot's Harness 12a-d. Variation of Drag Area with Pilot's Harness

1

-Introduction

The popularity of the sport of hang gliding has resulted in a demand for experimental facilities needed for airworthiness

evaluations and accident investigations of hang gliders as well as developments of hang glider designs. Aeroelastic effects make it difficult to accurately model hang gliders for scaled wind tunnel experiments and full scale wind tunnel tests are often prohibitively expensive. Instead, some countries have developed mobile aerodynamic test vehicles capable of carrying out

measurements normally made in a wind tunnel. The British facility, shown in Figure 1, is described in more detail in Reference 3.

Conventional hang gliders are weight shift control and the position of the pilot makes his aerodynamics an integral part of stability and performance calculations. Unlike wind tunnel facilities, where a hang glider can usually be tested with a dummy pilot, the hang glider attachments to a mobile facility are usually such that it would not be possible to fit a dxommy pilot with the glider. Thus the pilot's aerodynamics must be obtained from another source.

Very little information about the aerodynamics of human beings, particularly hang glider pilots, is available. Although some wind tunnel measurements have been made abroad, the data available is very limited and not particularly suited for use

with hang glider aerodynamic data obtained from the British mobile facility.

In order to obtain more detailed information, a series of full scale wind tunnel experiments on hang glider pilots has been carried out. The results obtained have been designed to be used in conjunction with the British hang glider aerodynamic test vehicle. Measurements were made on a number of pilots over a

range of pilot positions and wind speeds. The effects of different harnesses and the presence of a parachute were also investigated.

2

-1. Experimental Procedure

The main objective of this experimental programme is to obtain information about the drag of a hang glider pilot to use in conjunction with hang glider aerodynamic data obtained from the British Hang Gliding Association "'s mobile aerodynamic test facility.

This facility incorporates a six component balance capable of measuring all the aerodynamic forces and moments acting on a glider. The data obtained incorporates the interference effect from the hang glider's A frame but does not include the

aerodynamics of the A frame itself. Thus the measurements made during this wind tunnel programme need to account not just for the pilot but instead for the pilot and A frame as an integral unit.

The College of Aeronautics 8 ft (2.4m) x 6 ft (1.8 m) low

speed closed working section wind tunnel was made availabe for these measurements. The A frame was suspended from the roof of the working

section and the pilot's hang strap connected just behind the A frame, as shown in Figure 2.

A purpose built A frame was made to fit the tunnel with the top connected to a motor capable of varying the incidence over a

range of 45 degrees but holding the A frame rigid for any particular test condition. The height of the A frame was restricted to 4 ft to prevent the pilot lying too close to the floor. The A frames vary in shape and size with typical heights ranging from 4 ft to

just over 5 ft and bottom bars varying in length from 4 ft to 5 ft 6 ins. Appendix A details corrections to be applied to the wind tunnel

measurements for A frames much larger than the one used (height 4 ft, bottom bar 5 ft 3 ins). However, in most instances, these will be negligible.

For any A frame position, the pilot was free to "fly" as

in flight. Tests were carried out at five different pilot positions, shown in Figures 3-7, and these are described below. They will be referred to as positions 1-5 throughout the rest of this report.

3

-Position 1 With the A frame vertical, the pilot pulled the bar under his chest to simulate, as near as possible, the pilot pulling on speed.

Position 2 With the A frame set at 2 5 degrees to the vertical, the pilot held himself in a position typical to that he would adopt in trimmed (hands off) flight.

Position 3 With the A frame set at 41 degrees to the vertical, the pilot pushed out on the bar.

Position 4 With the A frame set at 41 degrees to the vertical, the pilot pushed out on the bar but also raised his chest higher than in position 3, to simulate more closely the pilot's position relative to the wind

(rather than the A frame) when pushing out.

Position 5 With the A frame set at 2 5 degrees to the vertical,

the pilot adopted a typical "Gorilla" (landing) position. Measurements were made on five different pilots. The drag

measurements were thought to be influenced by the way each pilot adopted the flying positions as well as by the pilot's size.

The effect of different harnesses was also investigated. Each pilot wore the same stirrup harness (stirrup harness 1) for comparisons between pilots and this is shown in Figures 3-7. Two pilots were also tested in different harnesses. One pilot was tested in another stirrup harness fitted with a parachute (stirrup harness 2) and in a fully enclosed harness also incorporating a parachute. The other pilot was tested in another stirrup harness without a parachute (stirrup harness 3 ) . Stirrup harnesses 2 and 3 did not have the padding of stirrup harness 1.

Each set of measurements were made over a range of wind

speeds chosen to simulate flight conditions as closely as possible. The lowest speed was limited by the tunnel to 8 m/s and a range of speeds taken above this up to 34 m/s - the highest speed thought likely to be encountered with today's hang gliders. A check was also made on the repeatability of the measurements.

4

-2. Experimental Results

Drag, lift and sideforce measurements were made for each pilot in the positions and harnesses specified in the preceding Chapter. The lift and sideforce were found to be negligible and will not be discussed further. The frontal area of a pilot is difficult to calculate with any accuracy so that a drag area instead of a drag coefficient will be used throughout this report. This is defined as

C^h = D/^pV^

2 where C_^A = Drag area Cm )

D = Drag (N)

3 p = Air density (kg/m ) V = Air speed (m/s)

The measurements were made in a closed working section wind tunnel and wind tunnel interference effects are not negligible. The data has been corrected to allow for the interference and details of this are outlined in Appendix B.

Figures8a-h show the drag area plotted against airspeed for the various configurations tested. The results appear to be dependent on the pilot's position and independent of velocity. Table 1 shows these results averaged over the speed range. The weights listed in Table 1 are for the pilot and harness together and serve as a comparison between pilot sizes and between harness weights.

There is a general tendency for the drag to be lower in positions 2 and 4 suggesting that the pilot drag is a minimum

when the glider is in steady flight near the trim condition. There is a sharp increase in drag, as expected, when the pilot is in

the "gorilla" position (see figure 8b) to approximately double the value for normal prone flight.

The measurements on one pilot were repeated and the results are shown in Figures 9a-d. Table 2 shows a comparison of mean

drag area (averaged over the speed range) for the two sets of data. The discrepancies are thought to be largely due to the pilot not being able to position himself in exactly the same way for each

2

5

-to the scatter obtained over the speed range for a particular configuration, and must be kept in mind when comparing results.

Figures lOa-d show the variation of drag area with the different pilots for stirrup harness 1. The results appear to be more dependent on the way each pilot positions himself rather than on the pilot's size. This is shown most clarly when

comparing pilots 4 and 5, who are the same size. However, the results do indicate a small tendency for the drag to increase with size, especially when the pilot is in a higher drag position.

Various harnesses are now on the market and measurements were made to investigate their effects on the overall drag. Figures lla-c compare stirrup harnesses 1 and 3 (both without a parachute) worn by pilot 5. The two harnesses are the same weight and there is no appreciable difference between the results.

Figures 12a-d compare the 3 harnesses worn by pilot 3. Again there is not noticeable difference between the two stirrup

harnesses although stirrup harness 2 was fitted with a parachute. However, the fully enclosed harness, with an integral parachute,

2

shows a marked reduction in drag of about 0.04 m . This value varies with pilot position though and further measurements with the fully enclosed harness are needed before more detailed

comparisons can be made. It must be noted though that the fully enclosed harness is 4 kg heavier than stirrup harness 1 and this should be taken into account whe calculating the improved

performance obtained from using an enclosed harness. The work done in References 4 and 10 has concentrated on the variation in drag

between harnesses (rather than variation due to other effects) and provide more detailed infoirmation in this area.

The results obtained have highlighted the main parameters which influence the drag of a hang glider pilot. The most

important of these is the pilot's position relative to the wind. Different values of drag should be used for different flight

conditions rather than the same average value being used throughout. The effect of the pilot's harness on the drag should also be kept in mind especially as more of the enclosed type come onto the market. The size of the pilot and the way he flies has also been

6

-found to have an effect on the results. However, the pilot's drag is only a part of the total information incorporated in

hang glider stability and performance calculations. The accuracy to which the pilot's drag is required is to a certain extent

determined by the magnitude of the hang glider's aerodynamic forces and moments measured on the mobile facility. This should be kept in mind if further investigations are made to obtain more detailed pilot drag information.

7

-3. Comparison with Other Work

Similar full scale measurements of the drag of human beings and hang glider pilots have been made abroad. In each instance, the results published give the drag of a man or a pilot and

harness only. In order to make a comparison, the A frame drag must be subtracted from the results obtained in this series of tests.

The drag of the A frame was measured over the speed range at each of the three A frame positions tested with a pilot. There was little variation of the drag area with speed and the mean drag area for each position is given in Table 3. These

figures have been subtracted from the total A frame and pilot

drag measurements and the results of this are presented in Table 4. It is interesting to note that the A frame drag is of the same order as the pilot^s drag. La Burthe and Walden have investigated the relative magnitudes of the drag from each component in a typical flight condition (References 5 and 6) and their breakdown of the total drag for one particular case is reproduced in Table 5.

Although the A frame drag is presented together with the king post drag, it appears that the relative magnitude of the pilot drag and A frame drag agree with the results obtained here. More noticeable improvements in the overall performance of a glider might be obtained by streamlining the A frame (and other similar components such as the king post) rather than by trying to reduce the drag of the pilot by further improvements to the harness.

In the past, results from measurements made by Schmitt (Reference 9) and summarised by Hoerner (Reference 2) have been used to calculate the pilot's drag. These involved full scale wind tunnel tests on sixteen men in various positions and the relevant results, for an average man, are given in Table 6. The measurements were made in an 8 ft x 10 ft closed working section with a shielded support strut. It is worth noting that no tare or interference corrections were made resulting in the figures quoted being slightly high. The errors will be largest in the high drag positions.

As expected, the drag of a man lying flat underestimates the drag of a prone hang glider pilot. This is because the pilot is rarely flat into wind and no account has been taken of the harness drag or the interference drag from the A frame.

8

-More recently, three separate sets of full scale

measurements on hang glider pilots have been made in the BMW wind tunnel in Munich, in the Eiffel wind tunnel in Paris and

at the Institute for Aerodynamics in Zurich. The results are published in References 4, 10 and 8 and reproduced in Tables 7, 8 and 9 respectively.

The experiments in Munich have concentrated on variations in drag between flying positions for the various types of harnesses on the market. The measurements were made in a closed working

section (5.77 m x 3.46 m) with slotted walls and it seems

unlikely that any wind tunnel interference corrections were made. However, they would be small for this size and type of working section. The pilot was suspended in his harness from the roof of the tunnel with the A frame, and the A frame and other tare drag subtracted from the results.

The results quoted for the knee hanger harness compare well with the results in Table 4 for the stirrup harnesses for both the prone and landing positions. No tests were made on a fully enclosed harness, but the cocoon harness with an integral parachute shows a reduction in drag to a value between that for a stirrup

harness and the fully enclosed harness worn by pilot 3. The results for the seated pilot lie between the values obtained by Schmitt

for a man sitting and a man squatting. Schmitt's value for a seated man could be slightly high because it is uncorrected for blockage, but it does not allow for the pilot's harness.

The results obtained in Paris were measured in an open jet tunnel and no wind tunnel interference corrections were made. The pilot was suspended in his harness with the A frame from the keel (without the wing) of a glider. The drag of the keel and the A frame were subtracted from the measurements. The main objective was to compare the drag of various prone harnesses and in each case measurements were made with the pilot in the minimum drag position. The results are shown in Table 8 and a density of 1.225 kg/m

has been used to convert the published data into drag areas.

The results given for the Mouette harness compare well with the various stirrup harness drags in Table 4 considering the

Mouette values are for a minimum drag position. The Keller and Magnum harnesses are both fully enclosed and their drag is

9

-comparable with that of the fully enclosed harness worn by pilot 3. The drag of the cocoon harness is suprisingly high compared with the results from Munich. This is probably because of the number of straps on the French cocoon harness

(tested with an added parachute) which might not have been present on the German harness.

Table 9 shows the results obtained at the Institute for Aerodynamics in Zurich. The experiments, carried out in a

closed wind tunnel, were made to compare the drag of a pilot with that of a dummy pilot (water bag) used to simulate the

pilot in hang glider stability tests. The pilot was suspended in his harness from the roof of the tunnel and a control bar

(rather than whole A frame) was supported by a strut from the floor. The drag of the strut and the control bar were subtracted from the measurements.

At first sight, the magnitude of the results appears

slightly high. However the tests were of a comparative nature and there is no evidence of any inteference corrections being made. The working section appears of a comparable size to the College of Aeronautic's tunnel where blockage corrections gave typically

2

a 0.02 m reduction in drag area. The harnesses worn by the two pilots had a number of straps and an additional parachute which would also tend to make the drag relatively high.

Generally, the various sets of wind tunnel measurements compare satisfactorily. Combining the different results gives a wide data base for pilot drag information ranging from the older seated type of flying to the modern fully enclosed harnesses. The work presented in this report has broadened the speed range over which measurements were made as well as determining the dependence of the pilot's drag on his position and the way he flies.

10

-Conclusions

A full scale wind tunnel investigation studying the aerodynamic characteristics of hang glider pilots has been carried out. The following conclusions can be drawn from the results

obtained:-1. Lift and sideforce measurements were negligible. 2. The pilot's drag area is independent of wind speed.

3. The pilot's drag area is largely dependent on the pilot's position. The drag is a minimum when the pilot is in a position typical to that for prone trimmed flight.

4. If the pilot adopts a gorilla/landing position his drag is about twice that for prone flight.

5. Variations in drag between pilots were found to be due to the way each pilot adopted the flying positions rather than the pilot's size.

6. There v/as no noticeable variation in drag between the different stirrup harness tested (with and without a parachute).

7. The fully enclosed harness gave a reduction in drag when compared with a stirrup harness.

8. The A frame drag is of the same order as the pilot's drag. 9. It is preferable for a range of pilot drag areas to be used

References

1. E.S.D.U. Blockage Corrections for Bluff Bodies in Confined Flows.

Item Number 80024

Engineering Sciences Data Unit London 1980

2. Hoerner, S.F. Fluid Dynamic Drag. 1965

3. Kilkenny, E.A. An Evaluation of a Mobile Aerodynamic Test Facility for Hang Glider Wings. Cranfield Report CoA No. 8330,

November 1983 4. Kurz, F. Tacke, W. Aerodynamik-Test im BMW Windkanal, "Drachenflieger" Magazine West Germany

La Burthe, C. Experimental Study of the Flight Envelope and Research of Safety Requirements for Hang Gliders.

NASA CP 2085.

Proceedings of the Science and Technology of Low Speed Motorless Flight Symposium. NASA Langley Research Center, Hampton, Virginia. March 1979

La Burthe, C, Walden, S.

Flight Safety of Rogallo Hang Gliders. Theoretical and Experimental Study of the Flight Envelope.

ESA-TT-634 ONERA-NT-1979-8

Maskell, E.C, A Theory of Blockage Effects on Bluff Bodies and Stalled Wings in a Closed Wind Tunnel.

Aeronautical Research Council R & M 3400 November 196 5

8. Oprecht, U. Kuster, W. Tschabold, R, Weber, P. Wildi, J.

Windkanalmessung mit Hangegleiterpiloten, Institut für Aerodynamik ETH Zurich 1979

9. Schmitt, T.J, Wind Tunnel Investigation of Air Loads on Human Beings.

TMB Report 892. January 19 54

10. Tisserant, Ph. Demain J'enleve La Sangle.

"Vol Libre" Magazine. France. January 1984

Appendix A Effect of A Frame Size on Drag Measurements

The measurements presented in this report have been obtained for an A frame 4 ft high with a bottom bar of

5 ft 3 ins. A frames vary in size with heights ranging from

4 ft to 5 ft and bottom bar lengths ranging from 4 ft to 5 ft 6 ins. Although it is not possible to calculate the exact variation in drag between A frames, an estimate can be made by considering the drag of a circular cylinder in two dimensional flow equal in length to the difference in size of the A frames.

The drag of a cylinder depends on the Reynolds Number

Re = pVd/y

where p = Air density (kg/m ) V = Air speed (m/s)

d = Cylinder diameter (m) )j = Air viscosity (kg/ms)

3 -5 Taking p = 1.225 kg/m , u = 1.79 x 10 kg/ms and

d = 1 inch (0.0254 m) , Re equals 1.4 x 10'* at 8 m/s and 5. 9 x 10^ at 34 m/s. Reference 2 gives the drag coefficient of a circular cylinder in two dimensional flow over this range of Reynolds Number as 1.2. Thus the drag area

Co A = V2 L d

where L = length of cylinder and d - diameter of cylinder

The change in drag area due to a 1 inch change in A frame length is

ACQA = 0.00077A m^

If the A frame height changes by H inches and the bottom bar by B inches then

if H is small. For large changes in H the length of the uprights rather than the height of the A frame must be considered.

A significant change in drag area would be ACoA > 0.01 m^

Appendix B Wind Tunnel Inteference Corrections

Various established formulae are available to correct

force measurements made on bluff bodies in closed working section wind tunnels and these are reviewed in Reference 1.

It is convenient to separate the blockage effects into two parts - solid blockage and wake blockage. The separated nature of the flow during these experiments results in the wake blockage being the more dominant effect and the solid blockage is assumed negligible in comparison.

Accurate calculation of the frontal area of a hang

glider pilot and A frame (which changes for each test condition) is difficult. Instead, Maskell's formula has been used to

correct for wake blockage. This is fully documented by Maskell in Reference 7 and takes the form

^w " ^DC/Ci3 " ^"^^^ "^ ^ V ^

where B = A^I/AT - geometric blockage ratio

e = wake blockage factor

C = measured drag coefficient C__, = corrected drag coefficient

A value of 2.5 has been assumed throughout for e as recommended by Maskell for three dimensional flow.

Table 1 Mean Drag Area of Each Configuration Tested Pilot 1 (64 kg) 2 (69 kg) 3 (78 kg) 3 (79 kg) 3 (82 kg) 4 (88 kg) 5 (88 kg) 5 (88 kg) Harness stirrup harness 1 stirrup harness 1 stirrup harness 1 Stirrup harness 2 Fully enclosed harness Stirrup harness 1 Stirrup harness 1 Stirrup harness 3 Position 1 0.26 0.29 0.30 0.30 0.26 0.33 0.31 0.31 F 2 0.25 0.29 0.25 0.26 0.23 0.31 0.26 0.27 3 0.24 0.27 0.26 -0.21 0.25 0.26 0.25 • • 4 0.27 0.29 0.32 -0.25 -1 5 — 0.53

-Table 2 Repeatability of Measurements Pilot 2 Stirrup Harness 1 Pilot's Position 1 2 3 4 Data Set 1 0.27 0.29 0.24 0.26 Data Set 2 0.29 0.29 0.27 0.29

Table 3 Drag Area of the A Frame A Frame Inclination to Vertical

0°

0.12

0.11

Table 4 Mean Drag Area of Each Configuration Tested (A Frame Drag Subtracted)

Pilot 1 (64 kg) 2 (69 kg) 3 (78 kg) 3 (79 kg) 3 (82 kg) 4 (88 kg) 5 (88 kg) 5 (88 kg) Harness Stirrup harness 1 Stirrup harness 1 Stirrup harness 1 Stirrup harness 2 Fully enclosed harness Stirrup harness 1 Stirrup harness 1 Stirrup harness 3 Position 1 0.14 0.17 0.18 0.18 0.14 0.21 1 2 0.14 0.18 0.14 0.15 0.12 0.20 0.19 I 0.15 1 t 0.19 0.16 1 3 0.15 0.18 0.17 -0.12 0.16 0.17 0.16 4 0.18 0.20 0.23 -0.16 -i 5 0.42 -1

Table 5 A Typical Breakdown of the Total Drag of a Hang Glider and Pilot in Flight

Source of Drag

Pilot and Harness (prone) Cables (40 m)

Control Bar and King Post Cross Spar Sail Friction Induced Drag % of Total Drag 3.6 4.3' 5.3> 17.1

7.5J

Table 6 Drag Area of an Average Man in Various Positions

Position

Lying

Squatting

Sitting

Standing (Side on)

Standing (Face on)

2 Drag Area (m ) 0.11 0.19 - 0.28 0.56 0.46 0.84

Table 7 Results Obtained in the BMW Wind Tunnel in Munich Pilot Seated (legs down) Pilot Seated Supine (legs flat) Pilot lying Supine

(face up, feet forward) Pilot prone (knee hanger harness) Pilot prone (cocoon harness

with non integral parachute) Pilot prone i (cocoon harness with integral ' parachute) Flying Position 30 km/hr (8.3 m/s) 0.38 0.30 0.26 0.17 0.18 0.15 60 km/hr (16.7 m/s) 0.39 0.30 0.27 0.185 0.184 0.17 Landing Position 30 km/hr (8.3 m/s) As for flight As for seated flight As for seated flight 0.43 0.57 0.68 60 km/hr (16.7 m/s) As for flight As for seated flight As for seated flight 0.43 0.51 ' j 1 i ! i

0.67 1

Table 8 Results Obtained in the Eiffel Wind Tunnel in Paris Cocoon harness (with Parachute) Keller harness (fully enclosed) Magnum harness (fully enclosed) Mouette harness (stirrup harness) Pilot Flat (8.5 m/s) 0.25 0.11 0.14 0.14 Pilot's head raised C12 m/s) 0.22 0.11 0.13 0.14 Pilot's Chest raised by 20° (12 m/s) -. 0.20

Table 9 Results Obtained at the Institute for Aerodynamics in Zurich Pilot Incidence (degrees) -10 0 +10 i ! Air Speed (m/s) 20 15 10 20 15 10 20 15 10 Drag Cm^) Small Pilot (72.9 kg) 0.210 0.206 0.199 0.216 0.218 0.216 0.235 0.233 0.229 Area Large Pilot (100.5 kg) 0.228 0.225 0.229 0.226 0.231 0.229 0.235 0.237 0.224

Figure 1.

The British Hang Gliding Association's Mobile Aerodynamic

Test Facility.

To Wind Tunnel Balance

O

Figure 3a .

Figure 3b.

Figure 4a .

Figure 4b.

Figure 5 a .

Figure 5b .

Figure 6 a .

Figure 6b.

Figure 7a.

Figure 7b.

8.6

8.5

8.4

0.3

8.2

8.1

-

e-• POSITION I PILOT 1 STIRRUP HARNESS 1

O

POSITION 2

o POSITION 3

V POSITION 4

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

0.6

0.5

0.4

0.3

^0.2

o

0.1

0-Q POSITION I PILOT 2 STIRRUP HARNESS 1

O POSITION 2

o POSITION 3

V

POSITION 4

A POSITION 5

A A

^ ^ t I

0 2 4 6 6 18 12 14 16 18 28 22 24 26 28 30 32 34

VELOCITY CM/S3

8.6

8.5

8.4

8.3

-o

8.1

-

8-Q POSITION I

O

POSITION 2

o POSITION 3

V POSITION 4

PILOT 3

STIRRUP HARNESS 1

V V • • • <^ <^

o

I

s

8

4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

0.6

0.5

0.4

0.3

z: 0.2

8

8.1

8-Q

POSITION I PILOT 3 STIRRUP HARNESS 2

O POSITION 2

8.6

8.5

8.4

8.3

z: 8.2

o

_o

8.1

8-• POSITION 1

O POSITION 2

© POSITION 3

V POSITION 4

PILOT 3

FULLY ENCLOSED HARNESS

© • © El V O ©

•

o

•

o

o

8

4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

0.6

0.5

0.4

0.3

0.2

8

0.1

0-Q POSITION 1

• POSITION 2

© POSITION 3

PILOT 4 STIRRUP HARNESS 1

J I L C^

o

8 2 4 6 8 18 12 14 16 18 20 22 24 26 28 30 32 34

VELOCITY CM/S)

0.6

0.5

0.4

0.3

0.2

8

0.1

-

8-a POSITION 1 PILOT 5 STIRRUP HARNESS 1

O POSITION 2

© POSITION 3

e

•

«W

•

O

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

8.6

8.5

8.4

8.3

z: 8.2

8.1

-

8-Q POSITION 1 PILOT 5 STIRRUP HARNESS 3

O POSITION 2

o POSITION 3

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

8.6 8.5 8.4 8.3 § 8 . 2 < : 8.1 0 -Kt -d

Fig

M l • •

wm • • 1

PILOT 2 STIRRUP HARNESS

• DATA SET 1 o DATA SET 2 ©

• •

ure 9a. Repeatability of

1 POSITION 1

§ g nP

Drag Measurements.

0.6|-0.5

0.4

0.3

z: 0.2

0.1

-

8-PILOT 2 STIRRUP HARNESS 1 POSITION 2

a DATA SET 1

© DATA SET 2

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 30 32 34

VELOCITY CM/S)

PILOT 2 STIRRUP HARNESS 1 POSITION 3

8.6

8.5

8.4

8.3

§ 8 . 2

o

o

8.1

-

8-a DATA SET 1

o DATA SET 2

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

PILOT 2 STIRRUP HARNESS 1 POSITION 4

8.6 r

8.5

8.4

0.3

^ 0 . 2

a

o

0.1

-

0-• DATA SET 1

o DATA SET 2

0 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

STIRRUP HARNESS 1 POSITION 1

6 p

A PILOT I C64 KG)

a PILOT 2 C69 KG)

5 - O PILOT 3 C78 KG)

© PILOT 4 C88 KG)

w

PILOT 5 C88 KG)

4

-3 - ^

0 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

Figure 10a. Variation of Drag Area with Pilot.

©

o

STIRRUP HARNESS 1

POSITION 2

8.6

8.5

0.4

0.3

z: 0.2

8

0.1

I-

e

PILOT

PILOT

PILOT

PILOT

PILOT

1

2

3

4

5

C64

C69

C78

C88

C88

KG)

KG)

KG)

KG)

KG)

e

C?

dp

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

STIRRUP HARNESS 1 POSITION 3

8.5

8.4

8.3

z: 8.2

8

8.1

PILOT 1 C64 KG)

PILOT 2 C69 KG)

PILOT 3 C78 KG)

PILOT 4 C88 KG)

PILOT 5 C88 KG)

1?

J

_f

f

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

STIRRUP HARNESS 1 POSITION 4

0.6

0.5

0.4

0.3

z: 0.2

-o

_0.1

-0>

A PILOT 1 C64 K G )

D PILOT 2 C69 K G )

O PILOT 3 C78 K G )

0

0

m

0

0

é'

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

VELOCITY CM/S)

PILOT 5 POSITION 1

8.6

8.5

8.4

8.3

z: 8.2

8.1

8

B

STIRRUP HARNESS 1 CNO PARACHUTE)

A STIRRUP HARNESS 3 CNO PARACHUTE)

A ^ A° ^ ^ A° ^

' ' ' I 1 I 1 , . l I I I I I L

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

PILOT 5 POSITION 2

8.6 r

8.5

8.4

8.3

z: 8.2

8.1

8-B

STIRRUP HARNESS 1 CNO PARACHUTE)

A STIRRUP HARNESS 3 CNO PARACHUTE)

S ft ^

J I I I I I I I , i I ' ' I I I I 1

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

PILOT 5 POSITION 3

8.6

8.5

8.4

8.3

z: 8.2

8.1

-

8-B

STIRRUP HARNESS I CNO PARACHUTE)

A STIRRUP HARNESS 3 CNO PARACHUTE)

° ^ % A iD f A

A

• • • I 1 1 1 1 1 1 I I I I L

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

PILOT 3

POSITION 1

8.6

8.5

8.4

0.3

0.2

0.1

-

8-B

STIRRUP HARNESS 1 CNO PARACHUTE)

O STIRRUP HARNESS 2 CWITH PARACHUTE)

© FULLY ENCLOSED HARNESS CWITH PARACHUTE)

^R © O E I © % © ^ © » © _© J- -L. J. J- J-

J-8

6 8 18 12 14 16 18 20 22 24 26 28 30 32 34

VELOCITY CM/S)

PILOT 3 POSITION 2

8.6

8.5

8.4

8.3

z:

a

8.2

8.1

B

STIRRUP HARNESS 1 CNO PARACHUTE)

O STIRRUP HARNESS 2 CWITH PARACHUTE)

© FULLY ENCLOSED HARNESS CWITH PARACHUTE)

.O

8 u

o

8 2 4 6 8 18 12 14 16 18 28 22 24 26 28 38 32 34

VELOCITY CM/S)

PILOT 3 POSITION 3

0.6

0.5

0.4

0.3

:c 0.2

-o

0.1

-0.

B

STIRRUP HARNESS 1 CNO PARACHUTE)

© FULLY ENCLOSED HARNESS CWITH PARACHUTE)

a •

o O © ©

i I I 1 I I I I I I I I I I I I 1

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

VELOCITY CM/S)

PILOT 3 POSITION 4

0.6

0.5

0.4

0.3

n

0.2

0.1

0-B STIRRUP HARNESS CNO PARACHUTE)

© FULLY ENCLOSED HARNESS CWITH PARACHUTE)

B E, B Q 0 ©

a B

e

8 2 4 6 8 18 12 14 16 16 28 22 24 26 28 38 32 34

VELOCITY CM/S)