Powering & Endurance Analysis (A009)

The Powering Analysis capability of Paramarine enables the designer to assess the effective power of their vessel including air resistance, appendages, fouling, propellers, roughness, shallow water, amongst others using a variety of regression data.

The effective power and resistance methods include:

• Andersen & Gukdhammer
• BSRA method
• Fung
• Fung 2
• Hollenbach
• Holtrop & Mennen
• Mercier
• NPL round bilge
• Oortmerssen
• Radojcic
• Savitsky planing craft
• Series 60
• Series 62A & Series 62B planing series
• Series 64
• SSPA
• Takashiro
• Taylor Gertler

Paramarine enables the derivation of all powering input data from geometry with a single object, thus eliminating the need for approximations and providing a single data store to which naked hull resistance prediction methods can refer. Components of resistance may be mixed and matched as required. Paramarine enables the schematic visualisation of the appendages within the 3D graphics pane, providing a swift reality check on the assessment. No additional information needs to be entered.

Given the effective power requirement, Paramarine enables the designer to find a suitable propeller from the AEW 20" series, SSPA_Ma high speed propeller series, or the Wageningen B series. The designer is able to search by specifying the shaft speed or diameter, or neither.

For any of the search methods, a series of limits may be applied to constrain the design. For example a maximum blade area ratio from construction considerations, or a maximum pressure coefficient from cavitation and acoustic signature considerations. Limits may also be placed on the range of shaft speeds, the maximum diameter and the maximum tip speed.

Submarine Resistance effective power analyses allow the designer to look at both surfaced and submerged hull and appendages resistance. The correlation allowance and coefficient of residual resistance values are iteratively calculated based on external form of the submarine casing. Near the surface the resistance increases due to the dissipation of energy in waves, which modifies the pressure distribution and hence is an increase in the residuary resistance CR. Methods for analysing mast and appendage drag are also included.

Endurance

The Endurance functionality within the Powering module allows endurance of a vessel to be analysed by specifying the operational profile, for either surface or subsurface vessels.

The propulsion and associated systems are modelled by defining alternators, battery banks, diesel engines, diesel generators, electric motors, fuel cells and gas turbines which can be in turn wired up to diesel tanks or LOX storage tanks objects modelled within the design.

A mission element outlines activities within a defined time period such as Hotel Load requirement, Battery Charging or Propulsion and selects the system elements required to provide power. By linking these elements it is possible to profile the Endurance of a surface vessel or submarine, whilst highlighting unfeasible activities, fuel or battery shortages