The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 03, 2009
Filed:
Jun. 18, 2004
Erik Johann, Berlin, DE;
Erik Johann, Berlin, DE;
Rolls-Royce Deutschland Ltd & Co KG, Blankenfelde-Mahlow, DE;
Abstract
The compressor blades of an aircraft engine are, in at least one natural-vibration critical area, designed such that at the blade leading edge (), the leading edge shock wave () attaches to the leading edge (), as a result of which a laminar boundary layer flow () on the suction side () quickly transitions into a turbulent boundary layer flow () which is kept constant and prevented from re-lamination by the further, continuous curvature of the suction side. Therefore, the transition, whose periodic movement is also suppressed, cannot communicate with a suction-side compression shock (), preventing the compression shock from augmenting the natural vibrations of the blade occurring under certain flight conditions. The blade leading edge can, for example, be designed as an ellipse with a semi-axis ratio equal to or smaller than 1:4.