Constant stress solid disk rotor of flywheel for flywheel energy storage system and design method thereof

A constant stress solid disk rotor of a flywheel, having an outer shape having an upper surface and a lower surface which are plane-symmetric with respect to a single-center rotation plane perpendicular to a rotation axis, an outer circumferential radius b, and a rotation center thickness h0, the constant stress solid disk rotor of the flywheel having a shape including a thickness decreasing region which decreases monotonously in thickness from a rotation center to a connection radius a and a constant thickness region located on an outer edge of the thickness decreasing region and having a constant thickness ha from the connection radius a to the outer circumferential radius b, wherein

• shape parameters including the outer circumferential radius b, the rotation center thickness h0, the connection radius a, and the outer edge thickness ha satisfy an equation below:
• [
• Expression
• ⁢
• 1
• ]
• a
• b
• =
• 1
• 2
• ⁢
• (
• -
• 2
• 1
• -
• v
• ⁢
• (
• 1
• +
• v
• -
• 2
• ln
• ⁡
• (
• h
• a
• h
• 0
• )
• )
• +
• (
• 2
• 1
• -
• v
• ⁢
• (
• 1
• +
• v
• -
• 2
• ln
• ⁡
• (
• h
• a
• h
• 0
• )
• )
• )
• 2
• +
• 4
• ⁢
• (
• 3
• +
• v
• )
• 1
• -
• v
• )
• )
• where ν is a Poisson's ratio of a rotor material.