VIII 

 HYDRODYNAMICS OF HIGH-SPEED WATER-BASED AIRCRAFT 



John B. Parkinson 



Langley Aeronautical Laboratory 

 National Advisory Committee for Aeronautics 



TABLE OF CONTENTS 



Page 



I. ABSTRACT 181 



II. INTRODUCTION 182 



III. SYMBOLS AND DEFINITIONS 182 



IV. BASIC CONSIDERATIONS 184 



Flight 184 



Take-Off and Landing 184 



Maneuvering and Handling 185 



V. NEW CONFIGURATIONS AND CONCEPTS 186 



High-Speed Hulls 186 



Hydro-Skis 187 



Additional Hydro-Ski Applications 188 



VI. HYDRODYNAMIC RESEARCH RESULTS AND PROBLEMS 190 



Planing Surfaces 190 



Underwater Lifting Surfaces 198 



Take-Off Resistance 199 



Hydrofoils and Struts 203 



Impact Loads and Motions 204 



High-Speed Test Facilities 204 



VII. CONCLUDING REMARKS 206 



I. Abstract 



Post-war trends in aeronautics have brought with them a significant increase 

 in the scope of hydrodynamics research and development for water-based aircraft. 

 Recent contributions include the high length-beam ratio hull and the hydro-ski landing 

 gear, both of which are compatible with the aerodynamic requirements of high-speed 

 flight. The hydro-ski provides a solution for the pantobase airplane, a means of reduc- 

 ing water loads and resistance at high water speeds, an effective ditching aid, and a 

 land-water mode of operation that minimizes or eliminates the need for a prepared 

 runway. 



Fundamental problems on which recent progress has been made include that 

 of the planing surface and the low aspect-ratio submerged lifting element near the 

 water surface. The take-off resistance of hulls at high water speeds, the emergence 



181 



