{"id":559535,"date":"2024-11-05T18:24:16","date_gmt":"2024-11-05T18:24:16","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/esdu-990312009\/"},"modified":"2024-11-05T18:24:16","modified_gmt":"2024-11-05T18:24:16","slug":"esdu-990312009","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/esdu\/esdu-990312009\/","title":{"rendered":"ESDU 99031:2009"},"content":{"rendered":"

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

Details are provided of a program, ESDUpac A9931, which
\ncalculates the maximum lift coefficient, the lift coefficient at
\nzero angle of attack and the lift curve of aerofoil sections and
\nstraight-tapered wings with high-lift devices deployed at low
\nspeeds. The basic wing (no devices deployed) may have camber and
\ntwist. The program includes methods that allow for the presence of
\na fuselage. For completeness, calculations can be made for the
\naerofoil and wing when there are no high-lift devices deployed but
\nthe prediction of the shape of the non-linear part of the lift
\ncurve should be treated with caution because it employs a technique
\ndeveloped for use when high-lift devices are deployed*. The method
\nis intended for use only for free-stream Mach numbers up to about
\nM<\/i> = 0.25. No allowance is made for ground effect.<\/p>\n

An auxiliary program, ESDUpac B9931, allows the prior
\ncalculation of the spanwise position of the section of the basic
\nwing that has the peak loading due to angle of attack. It is
\nnecessary to know that section because full runs of the main
\nprogram for wings and wing-fuselage combinations require its
\ngeometry.<\/p>\n

A companion program described in Item No. 93015 allows
\ncalculations of the maximum lift coefficient to be made for a basic
\nwing for subcritical Mach numbers. The program introduced in Item
\nNo. 93015 also permits aerofoil characteristics to be calculated
\nfor Mach numbers up to 0.4. However, neither the lift coefficient
\nat zero angle of attack nor the general shape of the lift curve is
\nestimated.<\/p>\n

The methods employed within the program to determine the maximum
\nlift coefficient and the lift coefficient at zero angle of attack
\nare those given in Item Nos 84026 and 94027 to 94031 for aerofoils
\nwith and without high-lift devices and in Item Nos 89034 and 91014,
\n92031, 93019, 95021, 96032, 97009 and 97011 for wings with and
\nwithout high-lift devices. The method of Item No. 96003 is used to
\ncalculate the lift curve. The calculation of the zero-lift
\nincidence, the lift-curve slope and the lift coefficient at zero
\nangle of attack for a basic aerofoil or wing section are made using
\nItem Nos 72024, 97020 and 98011, in preference to using the more
\napproximate methods given in other Items before Item Nos 97020 and
\n98011 were available. This provides greater consistency throughout
\nthe program although the changes in magnitude are small and of
\nlittle consequence in the overall construction of the lift curve.
\nSome Items employ a two-dimensional lift-curve slope from Item No.
\nAero W.01.01.05 in the estimation of device effectiveness and the
\nmethod of that Item is retained in such cases to preserve the
\nintegrity of the original correlations.<\/p>\n

The presence of a fuselage is modelled via its effect on the
\nzero-lift angle of attack, using the method of Item No. 89042, and
\nthrough its influence on the performance of high-lift devices if
\nthey are fitted close to the fuselage side. The method of Item No.
\n97003 is used to determine the fuselage effect on trailing-edge
\nflaps. The influence of the fuselage on the performance of
\nleading-edge devices is treated by assuming that they extend to the
\nfuselage centre-line. For the fuselage effect on maximum lift
\ncoefficient the user must enter an increment derived from
\nexperiment or based on experience as there is no Data Item method
\nfor the prediction of that contribution, which is thought to be
\nsmall.<\/p>\n

Section 3 highlights some particular features of the programs.
\nSection 4 describes the input files required by the programs A9931
\nand B9931 and Section 5 discusses the output. Section 7 provides
\nexamples of input and output files for specific cases. Section 6
\nlists the Derivation and References. Appendix A presents a flow
\nchart that gives an alternative description of the construction of
\ninput files for A9931.<\/p>\n

* For basic aerofoils and wings the angle of attack for the
\nonset of non-linear behaviour may be obtained from Item No. 88030
\nand is dependent on section geometry and, for wings, planform
\ngeometry. At present there is no Data Item that addresses the lift
\ncurve beyond that angle of attack, but it is likely that the
\nsubsequent non-linear behaviour up to maximum lift is also
\ndependent on section and planform geometry. These effects are
\nmasked by the additional effects associated with high-lift devices
\nwhen they are deployed and are not represented in the simple
\nfairing that models the lift curve as the maximum lift coefficient
\nis approached. However, comparisons with a few data have shown that
\nthe use of the fairing developed for cases where devices are
\ndeployed gives an improvement over a linear assumption and, in the
\nabsence of a more detailed alternative, this is used for basic
\naerofoils and wings to provide an initial estimate of the curve in
\nthe non-linear range.<\/p>\n","protected":false},"excerpt":{"rendered":"

Computer program for estimation of lift curve to maximum lift for wing-fuselage combinations with high-lift devices at low speeds<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
ESDU<\/b><\/a><\/td>\n2009-11-01<\/td>\n117<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":559546,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2675],"product_tag":[],"class_list":{"0":"post-559535","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\/559535","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\/559546"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=559535"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=559535"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=559535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}