PFFP: Pre-swirl Fairing in Front of Propeller

working principle

1. Water flow guidance and pre rotation. The pre rotation guide cover changes the flow of water towards the propeller through a specific shaped guide vane, causing it to produce pre rotation before entering the propeller. The diffuser can adjust the water flow in advance according to the direction of propeller rotation, either in a forward or reverse direction.

2. Reduce vortices and flow losses. In traditional propeller operation, a wake vortex with significant energy loss usually forms behind the propeller, leading to a decrease in efficiency. The pre swirl deflector can change the way water flows into the propeller in advance, reducing the generation of vortices behind the propeller and thus reducing energy loss.

3. Improve propeller efficiency. The diffuser pre treats the water flow, allowing it to enter the propeller at a more optimized angle and velocity, thereby increasing the utilization efficiency of the propeller blades and reducing blade load and energy loss.

Energy saving effect

The main energy-saving effect of the pre swirl diffuser is reflected in improving the efficiency of the propulsion system and reducing fuel consumption.

According to practical applications and experimental tests, the diffuser can bring a 2% to 6% improvement in propulsion efficiency, thereby reducing corresponding fuel consumption. The specific energy-saving effect is influenced by various factors, including the type of ship, speed, propeller design, and duct design.

1. Efficiency improvement: By optimizing the water flow in front of the propeller, energy loss can be reduced and propulsion efficiency can be improved, especially under high ship speed or large load changes.

2. Fuel saving: The improvement in efficiency directly reduces the resistance and load of the propeller, allowing the ship to use less power at the same speed, thereby reducing fuel consumption. The energy-saving effect is usually between 2% and 6%, but it can also be further optimized according to specific design and ship conditions.

3. Emission reduction effect: Due to the reduction in fuel consumption, greenhouse gas emissions are correspondingly reduced, making it environmentally friendly.

Application scenarios

Pre swirl deflectors are widely used in large vessels such as merchant ships, oil tankers, and container ships. Its energy-saving effect is quite significant, especially in long-distance navigation and high loads, which can effectively reduce operating costs.