Demonstration calculator

Wageningen B-series propeller calculator

Thrust, torque and efficiency of a Wageningen B-series or Gawn propeller are evaluated over the advance-coefficient range, with the operating point determined for the specified diameter and shaft speed, together with a screening check of blade area for cavitation. The Gawn series is limited to three-bladed propellers, but extends to pitch ratios beyond the range represented in the B-series data.

The Wageningen B-series open-water coefficients are calculated from the Oosterveld and van Oossanen regression equations, evaluated as published, with their Reynolds-number correction applied for Reynolds numbers above the approximately 2 × 106 reference condition of the underlying series data. The implementation was checked against a printed open-water chart for the two-bladed series by measuring the advance coefficients at which the thrust curves cross zero; six of the ten curves agreed within 0.002 in J, a difference smaller than the printed line width. The Gawn coefficients are a separate regression fitted to Gawn’s own model tests, and the Oosterveld correction, which belongs to the B-series, is not applied to them. Seawater density, dynamic viscosity and vapour pressure are calculated using the MIT seawater correlations rather than approximate constant-property values.

Propeller

Operating condition

A demonstration of method. The series is a regression over model tests of a particular family of blade forms, corrected to a single Reynolds number. It carries no skew, no rake, no wake field and no hull interaction, and the blade-area check is a screening rule rather than a cavitation calculation. A propeller designed for your vessel takes in all of these, and we support it through the classification society’s review.

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AwaitingEnter a propeller and press Compute.

About the calculator

Open-water performance from systematic series

The Wageningen B-series is the most widely used set of systematic propeller model tests: fixed-pitch propellers of two to seven blades, tested across pitch ratio and blade area ratio, with their thrust and torque coefficients fitted as polynomials in advance coefficient. The Gawn series does the same for three-bladed propellers of wide blade and high pitch. Between them they give a sound first estimate of a propeller's open-water efficiency and the operating point at a stated shaft speed and speed of advance.

That estimate is where a propeller design and a propeller and engine matching study begin. The series stands for a family of propellers; a study goes on to the particular propeller, its sections, the wake it works in and the engine it is matched to.

Taking it further

From a series estimate to a study