Advanced Aerodynamics and Hydrodynamics for Powerboats

Based on expertise developed by Jim Russell at University of Toronto and University of Michigan, AR has applied unique aerodynamic and hydrodynamic  algorithms that accurately represent tunnel hull, power catamaran, vee hull and vee-pad hull arrangements. The analysis highlights the design and setup parameters that affect optimized performance for all hull configurations.
 

Figure 3 - complex algorithms based on research and test results can give highly accurate prediction of aerodynamic, hydrodynamic and dynamic stability behaviour of high-performance hulls.

Figure 4 - Proven with full-scale race testing

Figure 5 - Alternative aerofoil shapes can generate higher lift forces and altered dynamic stability characteristics.

Figure 6 - Complex fluid flow modeling specifically for tunnel and vee hulls allows accurate computer modeling of these complex designs that fly in air on water.

From these original results and years of full-scale race-testing, advanced marine technology produced engineering relationships and proprietary algorithms that accurately define the unique interaction of hydrodynamic forces with aerodynamic forces of high-performance tunnel hulls, power catamarans, and vee hulls.

How it Works - Unique wind tunnel and water channel experimental results of low-aspect ratio aerofoil/hulls in close proximity ground effect (water surface) were proven through rigorous, extensive, full-scale testing.

Ground-effect tests were conducted in a high-speed, sub-sonic, wind tunnel using an image-wing (reflection) method.  The image-wing technique involves the use of an identical model mounted inverted with respect to the test model.

This additional wing model is, in effect, an image or reflection of the test with the distance between the two wings being equal to 2 X ground height represented. Tests made with the image-wing method have shown to correlate well with results of tests of a model moving over a still surface.

Russell's results show that aerodynamic performance of tunnel hulls and vee hulls are highly influenced by:

a) height above water surface (h/C)

b) aspect ratio of deck/tunnel region (b/L)

c) deck/surface thickness ratio (t/C)

d) aerofoil (deck/tunnel) shape*

e) angle of attack (α)

f) other factors**

** For example, Tunnel hull designs also incorporate sponson sides that act as 'end-plates' to the aerodynamic 'wing' section, which is shown to further enhance Lift/Drag performance.

Results of extensive testing has been correlated with full scale tunnel hull, power catamaran, vee hull and vee-pad hull tests that compared real-model characteristics of representative aspect ratio, height above surface and angle of attack with aerodynamic lift, drag and instability, at similar velocities.

*Research also included analysis of the affects of aerofoil shape on lift, drag and stability, using NACA shapes.  Russell's results proved that alternative aerofoil shapes can generate higher lift forces, improved L/D results.  Resulting changes in Dynamic Stability was also observed using some alternative aerofoil shapes, that can sometimes have undesirable results when used in applications of performance boat hulls. so careful performance analysis is required to optimize beneficial utilization.  AR's TBDP/VBDP design software and Russell's "Secrets of Tunnel Boat Design" book address these important issues for the performance tunnel boat designer.

Research shows also, that effectively designed vee hull deck and hull configurations have significant contributory aerodynamic lift characteristics, and can enhance vee hull performance significantly.

Complex fluid flow modeling specifically for tunnel and vee hulls allows accurate computer modeling of these complex designs that fly in air on water.

Jim Russell applies these advancements in newest versions of AR's TBDP©/VBDP© design and performance analysis software.

© Copyright 2015 by Jim Russell and AeroMarine Research® - all rights reserved. 
Material from this website may not be copied or used or redistributed, in whole or in part, without the specific written consent of Jim Russell or AeroMarine Research.