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TBDP©/VBDP© 'Trim Angles with Full Power (Angle Analysis)'
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BREAKTHROUGH! 
'Angle Optimization Analysis'
by AR's unique analysis and TBDP©/VBDP© software.


Performance analysis of any hull design when Full Power operation is considered is very valuable for performance optimization, and particularly for comparison of alternate design/setup consiierations.

TBDP©/VBDP© software's 'Optimize=Angle' analysis will use maximum power to find minimum trim angle (WAngle) to satisfy a solution at each velocity step through the operating range.

 

Figure 1- TBDP©/VBDP© graphic output
shows  performance indicators

When performance OPTIMIZATION is set for "Angle Optimization", your design will be evaluated through a range of specified Velocities. The minimum Angle of Attack (of planing surfaces) based on the specified (Maximum) Power available will be determined for each velocity.  TBDP©/VBDP© Performance Report for “Optimize = Angle” generates the trim angle (WAngle) required for the specified design at MAXIMUM Available Power - so Power will be approximately “maximum available” throughout the velocity range, and the WAngle required to meet this condition (velocity and power) is calculated. All other performance indicator values are resultant of these settings.

Note: this option provides the most comprehensive performance analysis, and the most detailed Performance Report. This setting is most often utilized to accurately evaluate detailed performance of hull and setup.

 

 Figure 2- TBDP©/VBDP© graphic output
'XCFDynamic' (Dynamic Stability)


This option is used at conceptual stages of design analysis and overall hull performance prediction, since it clearly and quickly identifies the operating ranges of many () key performance indicators such as Angle of Attack, Dynamic CofF (stability), Porpoising, Wetted surfaces, Lifts, Drags, etc. This option is extremely powerful when evaluating the performance of your proposed design over the full range of operating velocities.
 

 

 Figure 3- TBDP©/VBDP© graphic output
'Trim Angle' (WAngle)


Trends in the predicted performance indicators can be carefully studied to determine whether the performance is satisfactory or whether the design can benefit from further refinement. For example (see figures 2, 3), a good indication of the behaviour of a hull design in it's upper speed range, is often seen in the change in location of the "Dynamic Center of Forces" (XCFDynamic) or a change in the required "Angle of Attack" (WAngle). If either of these two performance indicators is shown to change more rapidly at higher velocities than they did at lower ones, then the hull design is likely becoming unstable and you should conclude that the practical maximum controllable velocity is being reached or exceeded. [Such changes in performance indicators are easily observed in the Performance Graphs and are specifically highlighted in the unique Performance Report].
 

'Optimize=Angle' analysis advantages

This performance optimization analysis method is the best method to observe performance at maximum power utilization, particularly when examining performance at top speed range.  The analysis shows all of the performance characteristics throughout the velocity range, while considering the trim angle (WAngle) that will be required with application of full power.

 

Figure 4- TBDP©/VBDP© graphic output Design 'Compare Feature' shows each performance indicator value comparing 2 or 3 alternative designs.


This method is the best approach to examine different design or setup alternatives, since it easily illustrates the performance differences through even small changes in required trim angle (WAngle) to achieve performance when applying full power.  The Graphic Compare feature makes such comparisons easy to see for 2 or 3 different design alternatives.

Some observations 'Optimize=Angle'
In practical operation, a lower trim angle is normally desired.  A design that achieves similar top speed, for example, but requires a higher trim angle to get there, is operating at lesser efficiency.  Examination of all performance attributes of a design while under full power, makes comparison to other designs very easy. 

The ability to apply full (Max) power usually means...

  • lower trim angle
  • lower lift efficiency, CLW
  • higher wetted surface
  • higher DW
  • lower L/D ratio (less efficient fuel economy)
  • better porpoising resistance
  • better visibility
  • better control/handling

Performance Analysis/Optimization Options - TBDP/VBDP can employ 4 different Optimizing methods of performance analysis, each highlighting different performance scenerios  and features. Get full performance data,data points for chosen analysis method:

1) Max Velocity or Test Velocity,
2) Trim Angles with Full Power,
3) Economy analysis with Lowest Power & Lowest Trim Angle,
4) Power Required analysis for specified Trim Angles. [includes acceleration and Elapsed Time]

Each optimizing method presents comprehensive performance results measures through full operating velocity range, detailed hull performance characteristics.


All above research results included in performance analysis software by TBDP©/VBDP©


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