Sec. X1.2 



SYMBOLS AND THEIR TITLES 



903 



prismatic, entrance, = 

 prismatic, forebody, = 



waterplane for roll, = /7./[(J5.yL)/12] = /,./ 

 (fi.083B^L) 



Cla — Coefficient, lateral area, = A,^/{LHm) 



Cld — Coefficient, load, of a planing craft, = 

 W/{'wB^)] alternative symbol is Cw but the 

 former is preferred 



Clf — Coefficient, local specific friction drag, as 

 distinguished from Cf , the mean or average 

 coefficient 



CpA — Coefficient, prismatic, afterbody, = 

 Va/{LaAm) 



Cp E — Coefficient, 

 ¥e/{LeA^) 



Cp F — Coefficient, 

 ¥p/iL,AM) 



CpB — Coefficient, prismatic, run, = Vp/{LkAx) 



Cpr — Coefficient, prismatic, vertical, = 

 V/(AwHx) = Cb/Cw = (Cy.Cx)/Cn. ; alternative 

 symbol <^ v 



Cj.L— Coefficient, thrust-load, = T/{0.5pAoVl); 

 see NOTE under Co 



CvM — Coefficient, virtual mass, in transient 

 flow or motion conditions; the ratio of the mass 

 of the body or ship and the surrounding en- 

 trained water to the mass of the body or ship. 

 This coefficient, equal to LO plus the coefficient 

 of added mass Cam , is always greater than unity. 



CwA — Coefficient, waterplane, afterbody, = 



A wa/{LaBm) 



C w E — Coefficient, 



Awe/{LieBx) 



CwF — Coefficient, 



A wf/{^fBm) 



CwR — Coefficient, 

 Awr/{LrBx) 



C ws — Coefficient, 



waterplane, entrance, = 



waterplane, forebody, = 



waterplane, run = 



wetted surface, of D. W. 

 Taylor, = S/ "v/AL, where A is the displacement 

 in tons of 2,240 lb of salt water of sp.gr. L024 

 (35.075 ft^ per ton) and L is the mean immersed 

 length in ft 



CpvA — Coefficient, prismatic, vertical, after- 

 body, = V a/{AwaH), where H is the draft at 

 midlength of the afterbody 



CpYE — Coefficient, prismatic, vertical, entrance, 

 = Ve/{.AwbH), where H is the draft at mid- 

 length of the entrance 



CpvF — Coefficient, prismatic, vertical, fore- 

 body, = ¥f/{AwfJI), where H is the draft at 

 midlength of the forebody 



CpvR — Coefficient, prismatic, vertical, run, = 

 ¥r/{AwrII), where H is the draft at midlength 

 of the run 



Cm/D — Mean-width ratio of the blades of a 

 screw propeller 



Ct/cr — Taper ratio of a cantilevered hydrofoil 



d — Diameter, boss or hub, of a screw propeller 



rf— Draft of a floating body or ship; alternative 

 symbols H and T; H is preferred 



dx — Draft of a floating body or ship at the 

 section of maximum area; alternative symbols 

 Hx and Tx 



D — Depth, molded, of a ship hull 



D — Diameter in general; diameter of a body of 

 revolution or of a propulsion device 



D — Drag, as a force opposing motion in a liquid 



Df — Towing force appUed to a ship model 

 during a test at the ship point of self-propulsion 



Db — Diameter, blade-circle, of a paddlewheel 



De — Drag, separation, due to differential 

 pressures in a separation zone 



Dp — Drag, friction 



D„ — Drag, hydrodynamic 



Di — Drag, induced 



Dp — Drag, pressure 



Dji — Drag, residuary, = Dt — Dp 



Ds — Drag, slope, of a floating body on an 

 inclined liquid surface 



Dt — Drag, total; the sum of the friction, 

 pressure, separation, and all other types of 

 drags due to relative liquid motion 



Dw — Drag, wind; the downwind force exerted 

 by the relative wind on a body or ship, to be 

 distinguished from the axial component ffwiod 



DsT — Diameter of steady-turning path 



■Dxact — Diameter, tactical 



d/D — Boss or hub diameter fraction of a screw 

 propeller 



ACp — Roughness allowance, specific, for a 

 body or ship, to be added to the smooth, flat- 

 plate, turbulent-flow specific friction resistance 

 coefficient 



dn, An — Streamline spacing or stream-tube 

 width, normal (transverse) to the direction of flow 



Ap — Differential pressure increase or decrease, 

 finite 



AR — Augmentation of resistance due to pres- 

 sure effects from a propulsion device 



ds, As — Equip otential-line spacing, along the 

 direction of flow 



diAU — Differential velocity increase or de- 

 crease, finite 



e — Base of Napierian or natural logarithms; for 

 example, log. 



