{"id":557451,"date":"2024-11-05T18:18:04","date_gmt":"2024-11-05T18:18:04","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/esdu-090152010\/"},"modified":"2024-11-05T18:18:04","modified_gmt":"2024-11-05T18:18:04","slug":"esdu-090152010","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/esdu\/esdu-090152010\/","title":{"rendered":"ESDU 09015:2010"},"content":{"rendered":"

INTRODUCTION<\/strong><\/p>\n

The general principles, by which aft-fixing of transition can be
\nused in wind-tunnel testing to simulate flow characteristics* at a
\nReynolds number higher than the test value, are described in
\nReference 1. As part of that process it is essential to obtain a
\ngood physical understanding of important flow features, such as
\nshock\/boundary-layer interaction, likely flow separations
\netc<\/i>., at the test Reynolds number, full-scale Reynolds
\nnumber and any other intermediate Reynolds numbers that are of
\ninterest. Prior to the test programme, this understanding is
\nobtained by the use of CFD methods and past experience of similar
\nconfigurations. It is also important to have a clear understanding
\nof the test objective(s).<\/p>\n

Following Reference 1, a simulation criterion is then selected
\nthat is closely linked to a dominant flow feature and the objective
\nof the test. For example, where conditions at the shock are of
\nparticular significance, the transition band positions may be
\nselected to match the shock position at the Reynolds number it is
\ndesired to simulate in the test. Alternatively, a boundary-layer
\nparameter (e.g.<\/i> momentum thickness) immediately upstream
\nof the shock may be chosen. If upper-surface separation near the
\ntrailing edge is of particular significance, then the momentum
\nthickness at the trailing edge is an appropriate parameter to
\nchoose. Once a suitable criterion has been chosen, forced
\ntransition locations (xtru<\/sub><\/i> and
\nxtrl<\/sub><\/i>) used in low-Reynolds-number tests can be
\ndirectly mapped to a higher Reynolds number
\n(Reeff<\/sub><\/i>) simulated by the use of aft fixing. It
\nshould be noted that it is not possible to satisfy all possible
\ncriteria simultaneously and the degree to which the selected
\ncriterion is satisfied will be a compromise. For example, if shock
\nposition is the chosen criterion, care must be taken to ensure that
\naccurate matching of this parameter does not result in a serious
\nmismatch in the boundary-layer condition immediately upstream of
\nthe shock.<\/p>\n

Because of these difficulties it is hard to provide a general
\n"rule-of-thumb" procedure and the purpose of this document is to
\nillustrate the procedure through the particular example of the F4
\nwing\/body combination at its design condition. It is shown how
\nsuitable simulation criteria may be selected and how upper-surface
\nand lower-surface transition locations, suitable for a test at low
\nReynolds number, may be chosen. Although the framework outlined in
\nReference 1 is generally followed, other flow parameters are
\nexamined where it is thought these are useful in developing a sound
\nunderstanding of the flow.<\/p>\n

In this example the test objective is taken to be the estimation
\nof drag at the design condition. A real test programme will cover a
\nrange of CL<\/sub><\/i>, rather than being focussed on a
\nsingle design point but the detailed analysis at the design point
\nserves to illustrate the procedure that should be applied over the
\nrange to be tested. However, as outlined in Reference 1, at other
\nvalues of CL<\/sub><\/i>, the investigation may lead to the
\nadoption of different simulation criteria and CFD extrapolation
\nprocedures.<\/p>\n

* It is implicit that the simulation represents a flow where
\ntransition on both upper and lower surfaces occurs at or close to
\nthe leading edge, as is usually the case at full scale.<\/p>\n","protected":false},"excerpt":{"rendered":"

Extrapolating Wind-Tunnel Data to Full-Scale Reynolds Number – Part 3: Example (I) Choice of Simulation Criteria and Transition-Strip Locations for the F4 Wing\/Body Combination at the Design Condition<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
ESDU<\/b><\/a><\/td>\n2010-03<\/td>\n41<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":0,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2675],"product_tag":[],"class_list":{"0":"post-557451","1":"product","2":"type-product","3":"status-publish","5":"product_cat-esdu","7":"first","8":"instock","9":"sold-individually","10":"shipping-taxable","11":"purchasable","12":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/557451","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=557451"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=557451"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=557451"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}