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:
Jan. 31, 2012
Filed:
Jan. 08, 2010
Mikiya Araki, Gunma, JP;
Yusuke Sone, Gunma, JP;
Takayuki Kojima, Tokyo, JP;
Hideyuki Taguchi, Tokyo, JP;
Seiichi Shiga, Gunma, JP;
Tomio Obokata, Gunma, JP;
Mikiya Araki, Gunma, JP;
Yusuke Sone, Gunma, JP;
Takayuki Kojima, Tokyo, JP;
Hideyuki Taguchi, Tokyo, JP;
Seiichi Shiga, Gunma, JP;
Tomio Obokata, Gunma, JP;
National University Corporation Gunma University, Gunma, JP;
Japan Aerospace Exploration Agency, Tokyo, JP;
Abstract
In a schlieren optical system, a laser beam is passed through the jet flow and the ambient around the jet flow, and a high speed sampling is performed using a high speed photo sensor while displacing measurement points. The value obtained by sampling represents a result of the optical path caused curved by a density gradient generated in an arc-shape from the center of the jet flow. The value is subjected to a high speed discrete Fourier transform and decomposed into frequency components which constitute the noise. Thereafter, Abel inversion is performed on data belonging to a particular frequency to obtain a density gradient in the radial direction from the center of the jet flow. The obtained density gradient is visualized in a graph display, so that the position of the sound source and the state of the jet flow can be accurately grasped.