A magnetostrictive system in aerospace engineering converts vibrations into electrical power through a process called magnetostriction. Magnetostriction refers to the phenomenon where certain materials change their shape or dimensions when subjected to a magnetic field. This property can be harnessed to generate electrical power from mechanical vibrations, such as those experienced in aerospace environments.
Here's how the process generally works:
Material Selection: A magnetostrictive material with suitable properties is chosen for the system. Commonly used materials include Terfenol-D (terbium, iron, dysprosium alloy) and Galfenol (iron, gallium alloy). These materials exhibit significant magnetostrictive behavior, which means they undergo substantial changes in shape when exposed to a magnetic field.
Mechanical Vibrations: In aerospace applications, mechanical vibrations are ever-present due to various factors like engine operation, turbulence, and structural interactions. These vibrations cause the magnetostrictive material to deform slightly in response to the changing stresses.
Magnetic Field Application: A magnetic field is applied to the magnetostrictive material using a permanent magnet or an electromagnet. When the material experiences the mechanical vibrations, its dimensions change slightly due to magnetostriction. This deformation leads to the stretching or compression of the material along its length.
Induction of Electrical Current: The changing dimensions of the magnetostrictive material alter the magnetic flux passing through it. According to Faraday's law of electromagnetic induction, a changing magnetic field induces an electrical current in a nearby conductor. In this case, a coil of wire is placed around or near the magnetostrictive material to capture the changing magnetic flux.
Electricity Generation: The induced electrical current in the coil can be harvested as electrical power. This generated electricity can then be used to power various systems within the aerospace vehicle, reducing the need for external power sources and increasing overall efficiency.
It's important to note that while magnetostrictive systems offer a way to convert vibrations into electrical power, the efficiency and power output of such systems depend on several factors, including the material properties, the amplitude and frequency of the vibrations, and the design of the magnetostrictive device. Additionally, these systems might not be suitable for all aerospace applications and must be carefully designed and integrated to ensure they function optimally in the specific environment and operational conditions.