The document summarizes the evolution of the ASW22DB glider through four phases from 1998 to 2003. Phase I involved building the ASW22BL with a smaller horizontal tail. Phase II modified the wing airfoil. Phase III included a new vertical stabilizer and retractable tail wheel. Phase IV added a new outboard airfoil profile, increased the span to 28m, and improved internal airflow. Performance gains anticipated included up to 11% at high speeds and improved climb. Flight tests verified the theoretical calculations and aerodynamic modifications. The completed glider met expectations by winning national competitions.
2. Project Phases
• Phase I- Build ASW22BL with 30% Less
Horizontal Tail Area
• Phase II- Modify HQ17 Airfoil Inboard
Wing
• Phase III- New Vertical Stabilizer and
Retractable tail wheel
• Phase IV- New Outboard Airfoil Profile,
Span Increase to 28m, Internal Air Flow
Improvement
3. Anticipated Performance
Gains From Project Phases
• 9% Performance Gain at Best L/D
• 11% Performance Gain at High Speeds,
(160km/hr)
• Improved Climb Performance From
Reduced Span Loading
• Equal flying qualities with 28m Span by
Maintaining Vertical Tail Volume Coeff.
(V/S.b)
4. Phase I- Build ASW22BL With
Smaller Horizontal Stabilizer
• 2.6% Less profile drag relative to wing
• Good stability/elevator authority on tow &
low speed flight (Minimum pilot wt. 88kg)
5. Phase II- Modify HQ 17 Airfoil
• Prof. Loek Boermans Designs Modification
to HQ17 Airfoil Lower Surface for 7.5%
Less Skin Friction Drag at High Speeds
(6.0 percent relative to wing).
10. Phase III- New Vertical Stabilizer &
Retract Tail Wheel
• Reasons For Building
-Drag reduction with modern profile
-Maintain 22BL tail volume coefficient(V/S.b)
with 28m span (add 30cm tail boom, 10cm span)
-Center hinged rudder
-Drag reduction with retract tail wheel
• Benefits
- 25% Less profile drag
- 2.2% Less drag relative to wing
- Better handling from new profile and center
hinged rudder
16. Phase IV- New Airfoil on
Outboard Wing, Span to 28m
• Reasons for Changes
- Improve lift distribution to near elliptical
- Less profile drag with Delft DU99-138
- Improve low speed, 1.8m more span
- Strengthen wing for 850kg max weight
• L. Boermans & M. Hulst designed new airfoil
and winglet for outer wing panel
• 2% Less profile drag at high speeds &
4% at low speeds relative to wing.