초록 ▼

A perforated sheet is diffusion bonded to a thin solid sheet. Each of the perforations of the perforated sheet is tapered, having a maximum diameter at the surface that is not bonded to the thin sheet and a smaller diameter at the surface that is bonded to the thin sheet. The bonded perforated sheet

A perforated sheet is diffusion bonded to a thin solid sheet. Each of the perforations of the perforated sheet is tapered, having a maximum diameter at the surface that is not bonded to the thin sheet and a smaller diameter at the surface that is bonded to the thin sheet. The bonded perforated sheet and thin sheet are included with other solid metallic sheets in a forming pack to be superplastically deformed into a structure. The bonded perforated sheet and thin sheet are placed on the top of the forming pack so that the thin sheet will face outwards after the structure is formed. After the superplastic deformation process is completed, the thin sheet is removed by machining to expose the perforated sheet and provide a structure for controlling laminar flow over the perforated sheet. The exposed surface of the perforated sheet includes the smaller diameter of each tapered perforation, while the inner-facing or blind surface of the sheet includes the maximum diameter. The formed structure includes internal passageways. The perforated sheet fluidly communicates the ambient atmosphere with the passageways. Control of laminar flow over the exposed surface of the perforated sheet is obtained by controlling the pressure in the passageways.

대표청구항 ▼

An apparatus for laminar flow control of an aircraft structure which is capable of being formed from superplastic deformation of a forming pack of stacked sheets comprising: a thin solid upper sheet, a perforated sheet adjacent said upper sheet having perforations therethrough, a core sheet adjacent

An apparatus for laminar flow control of an aircraft structure which is capable of being formed from superplastic deformation of a forming pack of stacked sheets comprising: a thin solid upper sheet, a perforated sheet adjacent said upper sheet having perforations therethrough, a core sheet adjacent said perforated sheet which is attached by a plurality of seam welds along said perforated sheet, and which provides a plurality of internal passages which communicate with the perforations in said perforated sheet, and a solid lower face sheet, wherein said solid upper sheet and said solid lower face sheet provide sealed surfaces so that the perforated sheet of the forming pack is capable of being internally pressurized for superplastic forming of the pack of stacked sheets, and wherein said thin solid upper sheet is capable of being removed to expose the perforations of said perforated sheet, so that the plurality of internal passages are capable of being in communication through said perforated sheet with the atmosphere located adjacent the aircraft structure.