Underwater exhaust scoop geometry analysis for a yacht

Summary

Underwater exhaust scoop geometry analysis for a yacht, assessing engine back pressure and propeller ventilation of the exhaust smoke.

Introduction

CFD simulations were carried out to study two different underwater exhaust geometries (pre and post optimization). The exhaust smoke pattern, its ventilation through the yacht propellers, the engine backpressure, and increased resistance due to the exhaust scoop were calculated. A total of six different conditions were tested, covering straight ahead and extreme turning conditions, displacement and planing velocities.

Results

The analysis identified the shortcomings of the first exhaust design (prior to optimization), confirming the client's intuition about its inadequacy. The increase in performance due to the new optimized exhaust scoop was quantified in terms of ventilation, backpressure, and additional vessel resistance. These results enabled the client to support their design decisions using state-of-the-art CFD simulations, resulting in a better overall design and improved yachting experience.

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— Tony Castro