NASA NACA-TR-210-1926 Inertia factors of ellipsoids for use in airship design《在飞船设计上应用的椭圆体惯性因数》.pdf

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1、_-k _._ c, k=O, k=1. /aw-c2E (u) = u = _ = sm-_/a-V_ = sin-and Lira _1 u-E (u)=l/2 (_- sin ._cos _)k-Othen 2ac 1 23/i-e 2 1 “ e_l :-e_a=O-(a_c2)_t_ _(_o-sincos _o)- e3 2 _ 1+_ )ea2c _ _) -_ 4U_e_7-_ (a _ c2)_r_(tanWhen X=0, _=sin -t e, so that_/_-e_ ( _ e_/l_e 2)ao=8o= e_ sin -lee4_ -f _ e)3o= eS (_

2、/i-_ -sin-ToProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-INERTIAFACTORS OF ELLIPSOID_ FOR USE IN AIRSHIP DESIGI_ 7In the limiting case c = O, e = 1 (circular plate) these give as beforeK,= K,=O, K,=8a -, 16 5 “7, =,_4. PROLATE SPHEROID. ab=c, k=l,

3、 k=0, _o=gdu. Thenwhereand2_a = (a _ ca)st_(u- tanh u)= “r = (a _ac,:)vt* 1/_, (sinh u cosh u _)4_ - ca e aca 1 - e*= _-_ (a- cl) stj = e_tanhu=sin_o= _+_ 1+4(a- ca) (a + X) e= + _-sinh u cosh u:ca+_, k1 -e2+a,when X = 0, these reduce to41 +sin _O=log tan (_+_)u=log 1-sine,a= _ log l + ei_Z_e_Ze.j_“

4、il +e“The special cases 3 and 4 are of course more readily obtained by direct integration.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Z“ “ Positive

5、directions of axes and angles (forces and moments) are shown by arrows.Force(parallelto axis)symbol.Moment about axis.- _ “- - Longitudinal I X X“ “ Latexat Y/ -_ - :_ . Serum! . Z Z-: / -_: _-_-Abaoluto coefficients of moment“- _Dim_eter, D“ Pitch (a) Aerodynamic pitch, p_- -: (b) Effective pitch,

6、p.“ :-_-. / (c) Mean geometric pitch, pg:%-: - -_- - (d) Virtual pitch, p_. -_ - (e) Standard pitch, p,_ _.r . Pitch ratio, p/D._ - : -_ “Inflow velocity, V-_ ; -N _ _:l_il_troam velocity, V., - - :-. - = 1 11 a- 76.04 kg. m/see. = 550 lb. ft/sec.“_ . i kg.mls_. =0.01315 I-P“ . ;: =- 1 i_far. -=0.44

7、704 m/sec.:“ ! m_._2.23693 mi/hr.wr“k .: _- ,_- _. - _ _C.=- _. -rolling .pitc.hmg.yawing .LMNPozitivedirec-tion.Y-_ ZZ-_XX - YAngle. Velocities.Designa- Sym- (comoo-Lineartion. i bot. nent aongl, axis).;.i.IAngular.Angle of set of control surface (relative toneutral position), _. (Indicate surface

8、byproper subscript.)4. PROPELLER SYMBOLS.Thrust, TTorque, QPower, P(If “coefficients“ are introduced all unitsused must be consistent.)Efficiency v = T V/PRevolutions per sec., n; per rain., NEffective helix angle _I,= tan -_ 2_-rn5. NUMERICAL RELATIONS.1 lb. =0.45359 kg.1 kg. =2.20462 lb.1 mi.=1609.35 m.=52S0 ft.1 m. =3.28083 ft.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- - - - . .i I_ _ “_ _ -o Lo“ . -#Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-