\n\tESDU 00026 presents a semi-empirical graphical method for estimating the pressure drag coefficient of boat-tails with length\/maximum diameter ratio up to 2.5 at zero angle of attack for Mach numbers from 1.5 to 4. The graphs, each for a value of boat-tail angle, present theoretical results obtained using the method of characteristics as a function of freestream Mach number and boat-tail length\/maximum diameter ratio; for conical boat-tails the graphs are for boat-tail angles of 2, 4, 6, 8 and 10 degrees and for circular-arc boat-tails for 5, 10, 15, 20 and 25 degrees. The graphs for circular-arc boat-tails also apply to parabolic-arc boat-tails and for both types the boat-tail angle is defined as the local angle at the boat-tail\/base junction. The theoretical results are modified to correlate the available experimental data; for conical boat-tails a single factor developed for ESDU 00017 is used while for the curved boat-tails an equation in terms of the boat-tail angle is given. Equations for the boat-tail angle in terms of the boat-tail dimensions are provided. The method applies when there is a jet efflux, provided the base pressure is below that at the end of the boat-tail; conditions for that to occur may be predicted using ESDU 00017 for the case of conical boat-tails. The method assumes there is no interference from any forebody, which requires that there are at least three diameters of cylindrical body ahead of the boat-tail. It is expected to predict the drag coefficient to within 0.003 for conical boat-tails and to within 0.005 for the smooth boat-tails. Worked examples illustrate the use of the method. For boat-tails with length\/maximum diameter ratio greater than 2.5 theoretical results are available in ESDU Aero B.S.02.03.02, and other ESDU documents give prediction methods for subsonic and transonic speeds.\n\t<\/p>\n","protected":false},"excerpt":{"rendered":"
Supersonic pressure drag of conical, circular-arc and parabolic boat-tails<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n ESDU<\/b><\/a><\/td>\n 2000-10-01<\/td>\n 18<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":557192,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2675],"product_tag":[],"class_list":{"0":"post-557184","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-esdu","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/557184","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:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/557192"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=557184"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=557184"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=557184"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}