Experimental and Theoretical Study of Aerodynamic Characteristics of Some Lifting Bodies at Angles of Attack

An (_xperimental and lh(x)rctical design study has been made of a generic family of lifting body configurations. The configurations all had a 75 ° sw('pt delta planforln with a rounded nose, but they had dif-f(,rcnt ut)t)er an(t lower surface camber shapes. The camber shapes varied in thickness and in the loca-ti(m of the maximmn thickness. The study consisted ()f models with a flat t)ottom and ut)t)er sur-fat(' camber variations, mo(lels with a fiat t.op and. lower surfac(' camt)er variations, and models with variations in both upper and lower surface cam-bet. The ext)('rim(,ntal results were ot)tainc(t in the Langley Unitary Plan Wind Tunnel at Math mini-bets from 2.30 to 4.62 for angles of attack fi'om-10 ° to 53 ° and inchMed 1)oth hmgitudimd and latcral-(lir('('tional a(wo(tymmfi(: ('haract(wistics. The theoretical results w('re ohtaine<l through the use of the Aero(lylmmic Preliminary Analysis System II. The results show that changes in the camt)er design cause (tistin(:t chang(_s in the acro(tynamic char-act eristics that should be c(msid(,re(t in the selection of a lifting-body shat)e. In gen(!ral, the fiat-bottom (tesigns with lq)per surface camber t)rovidcd greater (h'ag ti)r r('tar(tati(m at high angles of attack, but they ver(' (x)nsi(teral)ly ()ul of trim longitudinally for the chosen moment r(q'(w(_nce center. Th(' flat-to t) designs with lower surface camber, on the ()t.her hand, provided less drag at high angl('s of attack but could t)e more easily trimmed longitudinally. The generally goo(t agr(_em(mt between the theoretical anti exp(Mm(mtal results in(licales thai the calculativc techniques used h('r('in shouhl be a valu-abh_ aid in th(' design t)r()c('ss ()f lifting b()(lies in the SUl)ersoni(' speed range.