Pedal Powered Ultralight Info From Bruce Blake at AHA.

There is some good info contained in the below write up...

A Technical review of muscle-powered airships

1.      Introduction

Many are they who have dreamed of flying with the greatest of ease, under their own power.  Few have succeeded.  In the airship sector we now have three different types of muscle-powered aircraft that have flown and for which enough data can be found and upon which to base a technical review.  The following websites may be consulted for photographs and relevant data.

White Dwarf –

http://home.teleport.com/~reedg/whitedwarf.html

Zeppy –

http://www.endlessflyers.com/transmanche.htm

Propbike –

http://www.parabounce.com  (Click on Added Features)

2.      Data summary – all data is in f.p.s. customary units

          Table 2-1

          Notes

1.      Propeller efficiency was guesstimated for White Dwarf and Zeppy and M; for Propbike, efficiency was calculated.

2.      The propellers of White Dwarf and Zeppy and M are open-flow; the Propbike propeller is enclosed in a circular shroud.

3.      The propeller diameters for White Dwarf and Zeppy were estimated from measurements of photographs.

4.      For Zeppy, envelope length and diameter were estimated from measurements of photographs.

3.      Analyses

3.1            Drag coefficient

The first stage of analysis is to calculate the Reynold’s numbers and the overall drag coefficients for each aircraft.  For this task, the design airspeeds were taken to be as follows :

White Dwarf           -        10 n.mile/hour; 16.89 ft/sec

Zeppy                    -        12 n.mile/hour; 20.27 ft/sec

Propbike                -          6 n.mile/hour; 10.13 ft/sec

Project M               -        15 n.mile/hour;  25.33 ft/sec

Continued ..

Page 2 of 5

Below are tabulated the R_N and C_D for each aircraft, calculated at Sea level in ISA conditions.  The data available from Hoerner, Fluid Dynamic Drag was used (Pg. 14-1 and Pg. 3-8).

          Table 3-1

          Notes

1. At Sea level, ISA, R_N = ρLV/µ, where

    ρ = 0.0023769 slug/ft³, and µ = 3.719x10^-7 slug/ft.sec.

2. Drag coefficient is based upon Vol^2/3.

3.2     Power available

All three airships were originally intended to be muscle powered; the power available for each may be expressed in terms of the power (in watts) that a strong and fit male athlete can generate for a period of time sufficient for the acceleration of the aircraft and for the measurement of its true airspeed.

Lacking verifiable data, I have assumed that the following tabulation of athletic power is applicable.

          Table 3-2

3.3     Airspeed formula

In order to calculate the maximum airspeed for each aircraft, the following equation was used :

          V³      =     550xSHPxη_prop                            where          SHP = Table 3-2 (convert)

                             0.5xρxSxC_D                                            η_prop = Table 2-1

                                                                                      ρ      = 0.0023769 sl/ft³

                                                                                      S      = Table 2-1 (Vol^2/3)

                                                                                      C_D    = Table 3-1

Continued ..

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3.4     Achievable airspeeds

For a muscle-powered airship, the airspeed maximum is a fleeting quantity.  This is because no normal person can sustain a large power output for more than a very limited period of time.

However, based upon the assumption that a suitably fit man can reliably achieve the power outputs that are shown in Table 3.2, then the following airspeed maxima can be achieved.

          Table 3-3  Note 2

          Notes

1. The available power = watts/745.7  HP (from Table 3-2).

2. Airspeeds are shown in ft/sec and (mile/hr).

4.      Cost of flight experience  (US$)

4.1            Each of these aircraft is a single seater.  All three will incur up-front and ownership costs relating to acquisition, helium filling, hangarage, and insurance.

4.2            I have used the following formula for the estimation of monthly costs :

Cost   = A^0.5 + F/12 + H + I                         where  A = $ purchase

                                                                             F = Vol/1000 x $80

                                                                             H = $500

                                                                             I  = $50

          Note that “A” should include all of the costs of the purchase including the costs of initial helium fill, plus the equipment and materials needed for inflation and assembly.

          Table 4-1

          Notes

1. Experiential estimates were used here, except for Propbike.

    Purchase costs are based upon limited production.

2. This aircraft has a sophisticated propulsion system and has

thrust vectoring.

3. Hangarage is the largest cost item; it can be reduced.

Page 4 of 5

5.      Photographs

White Dwarf over

Continued ..

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Zeppy in flight

Propbike flying indoors (with artificial sky added)

This is a great compilation of info. Do you have a link to the original article?

Here is the original document (attached) should have the pics of the ships....

Attachment: A%20Technical%20review%20of%20muscle_01[1].doc (855.0KB)

Maybe we aught to go into the Hangarage business until we can pay for an airship!