How to Analyze 2-D Schlieren Photographs to Obtain the Density Gradient Structure of 3-D Flow Fields


Book Description

A technique is outlined by which density gradients visible in two- dimensional schlieren photographs can be analyzed to obtain the density gradient structure (i.e., the shape and location of density gradients such as shock waves and vortices) of three-dimensional flow fields. Practical application of the technique relies on obtaining a series of schlieren photographs of the flow field from different viewing orientations. The analysis is specialized to the case of a right-circular cone at angle of attack. Results are presented which show the shape and location of the bow shock of a 5 deg half-angle right- circular cone at a nominal Mach number of 5.0, a nominal free-stream Reynolds number per foot of 4,800,000 and angles of attack equal to 15 and 40 deg.




Schlieren and Shadowgraph Techniques


Book Description

Schlieren and shadowgraph techniques are basic and valuable tools in various scientific and engineering disciplines. They allow us to see the invisible: the optical inhomogeneities in transparent media like air, water, and glass that otherwise cause only ghostly distortions of our normal vision. These techniques are discussed briefly in many books and papers, but there is no up-to-date complete treatment of the subject before now. The book is intended as a practical guide for those who want to use these methods, as well as a resource for a broad range of disciplines where scientific visualization is important. The colorful 400-year history of these methods is covered in an extensive introductory chapter accessible to all readers.




An Experimental Investigation of the Flow Field Around a Yawed Cone


Book Description

An experimental investigation of the flow field associated with a highly yawed cone was conducted at a Mach number of 5 and a free-stream Reynolds number per foot of 4,400,000. Surface static pressure measurements, flow-field surveys and schlieren photographs were obtained on a sharp five-degree semi-vertex angle cone at an angle of attack of 24 degrees. The results of the measurements indicate that the flow field on the leeward side of a highly yawed cone is very similar to that of a circular cylinder in supersonic cross flow. The essential difference between these two flow fields is the presence of a disturbance from the tip of the cone which separates the gas which has passed through the shock wave on the windward side from the flow which has passed through the weaker portion of the shock wave on the leeward side of the cone. (Author).







Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.










Aeronautical Engineering


Book Description

A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).







NASA SP.


Book Description