Alternating helicoid cell structure and methods of producing the same

A cell structure for use in an acoustic panel, the cell structure comprising:

• a continuous first boundary wall having a cell height measured between a floor side and an entrance side, the continuous first boundary wall having a central axis and defining a first cavity with a regular shape cross section perpendicular to the central axis;
• a continuous second boundary wall disposed coaxially within the first cavity and defining a second cavity, the second cavity having the regular shape cross section perpendicular to the central axis, the second cavity having a floor side covered by the cell structure floor, the cell height, and an entrance side defined by a second incircle;
• a first number of inner chambers disposed within the second cavity from the second cavity entrance side to the cell structure floor, each of the inner chambers having an equal inner chamber cross sectional area created by radially dividing the second incircle, the inner chambers being rotated in a first direction around the central axis by at least p rotations per inch from the second cavity entrance side to the cell structure floor;
• and
• a second number of outer chambers disposed in a volume between the continuous first boundary wall and the continuous second boundary wall, from the first cavity entrance side to the cell structure floor, each of the outer chambers having an equal outer chamber cross sectional area created by radially dividing the first incircle into equally sized outer sections, the outer chambers being rotated around the central axis in an opposing direction to the first direction by the at least p rotations per inch from the first cavity entrance side to the cell structure floor.

An acoustic panel comprising:

• an array of a plurality of helicoid cell structures, each helicoid cell structure comprising:
• a continuous first boundary wall having a cell height measured between a floor side and an entrance side, the continuous first boundary wall having a central axis and defining a first cavity with a regular shape cross section perpendicular to the central axis;
• a continuous second boundary wall disposed coaxially within the first cavity and defining a second cavity, the second cavity having the regular shape cross section perpendicular to the central axis, the second cavity having a floor side covered by the cell structure floor, the cell height, and an entrance side defined by a second incircle;
• a first number of inner chambers disposed within the second cavity from the second cavity entrance side to the cell structure floor, each of the inner chambers having an equal inner chamber cross sectional area created by radially dividing the second incircle, the inner chambers being rotated in a first direction around the central axis by at least p rotations per inch from the second cavity entrance side to the cell structure floor;
• a second number of outer chambers disposed in a volume between the continuous first boundary wall and the continuous second boundary wall, from the first cavity entrance side to the cell structure floor, each of the outer chambers having an equal outer chamber cross sectional area created by radially dividing the first incircle into equally sized outer sections, the outer chambers being rotated around the central axis in an opposing direction to the first direction by the at least p rotations per inch from the first cavity entrance side to the cell structure floor;
• and
• a continuous surface layer comprising, for each of the plurality of helicoid cell structures, a respective perforated lid.