Homepage of Theo Volkers
This homepage presents:
model aircraft software: simulation of F3B Launch and speed task
model aircraft software: simplified F3K launch simulation
an article titled: "Aerodynamics of a DLG unravelled"
a copy of Memorandum M-276 titled
"Preliminary results of windtunnel measurements on some airfoil
sections at Reynoldsnumbers between 60,000 and 500,000"
- a copy of an article written for Flug + modell-technik: "Windkanalvermessung der Eppler Profile E 385 und E 387"
some interesting links, photographs and sink rate analysis which highlight my hobby
Analysis of the F3B Launch and Speed taskSoftware: F3B launch and speed task
sottware is embedded in an excel file and written in a VBA macro. It is
written almost 20 years ago. At that time the results matched the
actual performance. At present it still gives insight in the effect of
variations of the input parameters.
Analysis of the F3K Launch
simplified launch simulation
This software is a
simplified launch simulation of a DLG model. It is embedded in an excel file and written in a VBA macro. It can
be used to get insight in the effect of change of mass, minimum air
drag and release speed on end height.
Article: "Aerodynamics of a DLG unravelled"
PDF file with said article
An article written for "Flug + modell-technik" Feb. 1980
with help from L. Boermans and interview with W. Thies (in German language)
Copy of Memorandum M-276.
This is a preliminary
report on wind tunnel measurements performed
study on some airfoils that were popular around 1977.
report has never been finished, but the pictures in the report speak
themselves for all people who are interested in airfoil characteristics.
Measured Eppler 387 airfoil characteristics from Memorandum M-276
Comparison of XFOIL (default settings) computations with measurements from memorandum M-276
Some interesting links related to RC
Homepage of De Starthaak
Photographs which highlight my hobby
Start of the F3b Cobra
Landing of the Cobra
Nico van de Burg and Theo Volkers launching the ZEFIER
and three proud builders
of their team design "Zefier", in memory of Gerrit Versteeg
Alsema Sagitta, 4m span
F3J NAN Explorer1, 3.5m, converted to F5J; the orange one far right on
the groupsphoto 2014 F5Jcontest Deventer
Launch of my Explorer
Tiger fleet of Ornithos winterproject
Sink rate Analyses for Stream NXT and Nan Xplorer1
Computed Sinkrate Stream NXT, based on
analysis on measured wing sections at 1, 34 and 65cm span
and estimated parasitic drag.
Corrected version published on 17 June 2020
Computed Sinkrate NAN Explorer1, based
on XFOIL and analysis on measured Mid section
My F5J (former F3J), 3.5m span Explorer
from 2006 has
mass of 2.4kg. Current F5J Explorers weigh only half this value.
Theo Volkers for
questions or comment
Last update January 21, 2021