Current research exists showing the efficiency of vessels using a propeller based propulsion system can be improved by designing a more efficient alternative model. The propellers on ships work by converting rotational motion into thrust. Therefore, as the blades spin it creates a pressure difference between the front and back surfaces that accelerates the water behind the blades creating a force.

For conventional propellers, an efficiency of 40-50% is achieved where much of the translated energy is lost to induced and frictional drag. Furthermore, this lost energy from reduced efficiency requires more fuel consumption and wasted energy to move a large vessel. This creates a need for a system that is significantly more efficient to reduce costs and greenhouse gas emissions.

A new system can be developed by researching aquatic animals and the way they move through the water. Researchers study these animals in their environment, offering promising examples of optimal fluid dynamics for means of biomimetic propulsion . Using the evolved body shape, propulsion mechanism, and swimming pattern of aquatic animals we hope to design a biomimetic propulsion system that can outperform conventional underwater propellers.

Our first design, will be similar to that of a dolphin’s flipper geometry and motion pattern. Dolphins have a tailfin that creates thrust by moving in sinusoidal pathway propelling water in the opposite direction of motion. Its dynamic motion pattern results in a high propulsive efficiency which is a desirable characteristic for our project.

The goal of this research project is to create a propulsion system based on flippers as an alternative to propellers on water vessels. Our purpose is to achieve a higher efficiency than conventional propellers by an alternative biomimetic propulsion system using flippers inspired by the evolution of aquatic animals.

Our project aims to create an alternative flipper propulsion based system that is more efficient than conventional propellers. Current ongoing research demonstrates efficiencies of biomimetic propulsion systems to be greater than 80%. The current propellers that exist are inefficient and require more fuel and energy compared to multi-joint biomimetic propulsion systems. With our multi-joint design of a biomimetic propulsion system, we could potentially be saving millions of dollars for water vessels from fuel and energy reduction and reducing maritime contribution of greenhouse gases. Additionally, our multi-joint biomimetic design will reduce noise disturbances to marine environment for aquatic animals that use sonar navigation methods.

Our new design will consist of two flexible fins with opposing directional motions. Each mechanism consists of two degrees of freedom of oscillatory translational motion and rotational motion. Each joint will be controlled by a different servo motor. Each servo will be programmed and tested to perform at an optimal frequency of motion for maximum efficiency while providing enough thrust for a vessel to cruise. At the rotational axis, a fin will be attached and tested for optimal geometries and rigidity to produce maximum efficiency while providing enough thrust to cruise. Flipper geometries will take shape of animals such as dolphins, large whales, and fish. The design will be performed in a water tank, which will serve as a testbed to perform multiple tests for different shapes of fins comparing geometry, rigidity, and frequency to efficiency, thrust power, and mechanical power.

The components for testing must be waterproof and corrosion resistant as the electrical motors and sensors may come in contact with water inside the testing tank. This potential hazard will be monitored and testing will be performed with great caution following strict safety guidelines.

To measure the efficiency of our biomimetic propulsion system, we must measure thrust and mechanical power.

Where, Efficiency = Thrust Power/Mechanical Power

The thrust will be measured by analyzing the dynamic pressure before and after the propulsion of water in the tank. A pressure transducer will be able to measure the dynamic pressure of moving water in the tank propelled by the flippers/propeller. The mechanical power will be measured from the current required by the servo when under load to produce torque and the speed of the servo motor. This data will be acquired through either a data acquisition microprocessor or oscilloscope in a UCI lab. Tests will be performed for the flippers and compared to a 4-blade propeller as they show the greatest ranges of propeller efficiency.

The overall significant of the project to increase the efficiency of water crafts by replacing the conventional inefficient propellers with a new biomimetic propulsion system using flippers. If our system is successful we could save millions of dollars of fuel and energy reduction on current ships, vessels, and boats. Environmentally, we are reducing the noise disturbance that conventional propellors harm marine life with that use sonar navigation methods.