Diana 2

Experience gained over a design, construction and operation of the SZD-56-1 sailplane model pays now. Pilots flying the hitherto built DIANA ships, over the recent years have broken numerous records.

To the verified already, still unconventional design features I am adding now a sensational, bright new aerodynamic design of a wing, by Krzysztof Kubrynski. Combination of these two features forms a unique to a world scale sailplane for the 15-meter Racing Class: Diana-2.

This one will be distinguished by:

·    the aerodynamic design, based on the original authors methodology in sailplane aerodynamics – for the first time employed on this project

·      the unconventional, straying from commonly used design solutions – this become a distinguishing feature of DIANA gliders

·      the unattainable till now scale of available wing surface modification – transmitting directly onto the range of available weather condition

The available surface loading could be increased twofold from 28 to 58 kg/m² (5,73 -11,85 lb/ft² ), while the ballast in wings surpasses the glider empty weight by 60 kg (132,28 lb) – not to be found in any other design.

This is really a sailplane for all weather conditions.

Bogumił Bereś

Technical data

Performance

Manufacturer: Avionic, Górki Wielkie, POLAND
Sales representative: Jerry Zieba

8051 N. Wisner
Niles, IL 60714
847 384-1144 Phone
847 384-1154 Fax
jerryzieba@dianasailplanes.com

Technical Description

With today's aerodynamics, computers and software, it was possible to make the sailplane really modern. Estimated possible reduction of profile drag of the actually used Diana's airfoil can achieve about 20%. Taking into consideration the possible effect from lowering the adverse aerodynamic interference, the reduction of parasite drag by making wing slightly bigger and installing winglets to reduce induced drag, the increase of max. L/D about 10% and farther reduction sink rate at higher speeds can be expected. Aerodynamic design of the new wing was performed by Krzysztof Kubrynski (Warsaw University of Technology). The new wing planform is totally curved. This solution lets reduce both induced drag and wing profile drag, and allows to expect proper wing stall progression. Wing profiles are changing along the span and meet aerodynamic requirements in all sections in the best manner. Diana-2's airfoil sections are even thinner then before, ranging from 12.8% at the root to 12.2% at the tip (and much less at the winglets). Additionally they are modified at the wing/fuselage junction. The flaperon chord is 17% and they can be deflected -2 to +28 deg. Aerodynamic philosophy of new Diana's airfoils is slightly different then that of other sailplanes and aerodynamic characteristics are expected to be slightly more profitable, especially at lower speeds. At the same time, even the profiles are thinner than original Diana's airfoil, the stiffness and strength characteristics are much better, and a cross section area is higher. This is important for wing weight and volume of water ballast. Pneumatic turbulators are used to enforce turbulent transition on the lower flap surface.

Aerodynamics of the wing is quite new, but the proven inner wing structure is retained. The entire internal wing volume is used as integral water tank. The wings can carry 240kg / 63.3gals of ballast. Also the cockpit is slightly modified internally in order to make it more comfortable for taller pilots.