Downloaded from https://www.everyspec.com LIST OF SYMBOLS U = distance from origin of coordinate axes F, = unit load on breechblock thread to origin of rifling curveэ 'mer radius; AF - force increment linear acceleration of projectile - acceleration of gravity a. = maximum projectile acceleration G = number of rifling grooves; shear modulus A = area of section; general expression for h - depth of rifling groove; depth of keyway area I = area moment of inertia, general ex- A. - nozzle approach area pression Ab - bore area J = area polar moment of inertia A. = chamber area k = radius of gyration of projectile A.
- nozzle exit area k, - high temperature strength reduction A, = original nozzle throat area; projected factor area of nozzle K - kinetic energy A, = nozzle throat area K, = constant in rifling torque equation for A. = nozzle area at distance x from the throat constant twist &A4 = change in nozzle throat area L f axial length of rifling curve; length of b - twice distance from origin of rifling to engaged thread; length of key; length point of maximum pressure; outer radius of increment C weight of propellant charge L' length of diverging cone CMP = computed maximum pressure L load factor d, = depth of thread L, - length of nozzle cone D = diameter varying from D, to D.; mean L.
required maximum length of chamber diameter; general expression for diam- M = general expression for moment eter; general expression for flexural M, = mass of projectile rigidity M, = recoiling mass; momentum of recoiling D, = outside diameter of liner; inside diameter mass of jacket M,. - specified momentum of recoiling mass D,, = bore diameter LAI, = required change in momentum Ai, = inside diameter n - exponent defining rifling curve LiD.. = mean diameter; mandrel diameter n. = twist of rifling stated in calibers per turn D.
= outside diameter N = induced force normal to rifling curve aD, = nominal clearance between bore and p = constant in equation for increasing twist projectile rifling; general expression for design E = modulus of elasticity; propellant po- pressure tential PA = pressure at point A of equivalent bore E, = equivalent modulus of elasticity p = chamber pressure; true computed Rres- ,. = modulus of elasticity of ring sure ESP = elastic strength pressure pt = autofrettage pressure -. = equivalent stress factor p, = propellant gas pressure =,, natural frequency p,. = maximum propellant gas pressure I, = firing rate pi = internal pressure F - general expression for force; specific p..
= computed design pressure, based on impetus; nozzle thrust PIMP F, = pro~vllant gas force p = external or outside pressure; reservoir F . --- nozzle force pressure p = cradle key load induced by rifling torque p. = pressure induced by shrink fit F, = thread load; thrust at nozzle throat, at pA = design pressuic at nozzle throat.; pitch Mach No. I p. allowable pressure 4 N. vi.i SViii