Downloaded from https://www.everyspec.com CHAPTER 1 DISCUSSION OF THE PROBLEM 1-1 INTRODUCTION propelling gases is an important part of the total energy of the process. The study of motion of a req inpartiing of high velocities to projectihers projectile inside the gui tube is not a matter of c suppir ies trem endous force. t he source of the energy simply applying Newton's laws to the motion of which supplies these forces must be readily nianu- N safely appliedl.
At various tinies, proposals have )(eumae orutliatonofenergy prvddb tepate gas is evolved from the propellant; the eupmotion of the gas so produced; and the effect of the projectile regarded as a point maass, but a factured, easy to transport, and capable of being complicated study of the rate at which the high V4 means other than explosives, such as compressed this gas oU the motion of the projectile itself. Tine air, electromagnetic force, and centrifugal force.
passage of the projectile itse Te 'fhis arhowver noresltshav ben ataiied passage of the projectile stresses the( tube mechan- *Ths far, however, no esults have beaptp attained ically and subjects the interior of the barrel to siding creal y om chemical explosives, friction. The passage of high temperature gases, in realized from ballistac explosives, addition to the high pressures generated, heats the Interior l)allistics of guns (that branjch of ballistics barrel to the extent that chemical interaction with (leiig with motion iipartedl to a projectile by a tile metal itself occurs.
gun) comprises a study of a chemical energy source, Interior ballistics is defined as tile branch of S a working sul)stanice, and the accessory apparatus applied mechanics which deals with the motion and for controlling the release of energy and for directing behavior characteristics of projectiles while under the, activity of the working sub~stance'. ()f allied the influence of the gases producedl by tile propellant. interest is the iiiechanical functioning of guns and As an applied science it is still much of an art accessories. (eea information the types of guns and largely empirical.
The phenomena with which and their coistruction and functions is given ii it deals are explicable *i terms of well established i(,ference 1. Refereinces applicable to each chapter physical and chemical principles. Unfortunately, the of this I landbook are given at the end of the chapter.
phenomena are complex and related in subtle and Since unnecessary weight is an unjustified logistical obscure ways so that considerable experience and extravagance, weapons are designied to operate under judgment are necessary in the application of the greater extremes of teimlperature and pressure thai principles if trustworthy theoretical results are to are usually encountered in tit(h use of nonmilitary be derived. There occur in the formulation of the enigines.
Because the time cycle involved is quite theory quantities which are difficult to determine small, there is not suflicient ti iie for the consuniai- by independent measurement because their proper tioti of slow processes such as heat transfer. ('omi- values for particular cases depend in obscure ways sequently, it is necessary that the chemical energy on the particular circumstances of the case con- source also furnish the gaseous products which l sidered. They have the nature of empirical correction themselves constitute the working substance.
This factors whose values can frequently be estimated S energy source may lbe a solid propellant, as in most only from the results of numerous examples in- guns. or a liquid fuel and oxidizer source, such as volving comparison of the theory used with tile is soilietillies lised ill rocket propulsion. records of actual firings. The beginner is, therefore, I'ropellamits are studied from several aspects. forewarned to he on his guard. All theoretical results Thermodynaiic properties indicate tile release of should be as firmly backed up by comparison with ais much energy per uinit weight as may be con- actual firings as is possible. In this sense the theory sistent with other demands.
Studies of the mech- serves as a means of interpolation between, or "allisill of (hecolipositiou, indicate the effects of uneoii- extrapolation fromn, existing designs. yollhlble parailleters such mis ambient teillperature. The subject of interior ballistics of guns has been D)yunic's of tlihe gases are necessarily a subject of investigated through more than 200 yeatrs, starting iiivestig tii Io eemiasi, theii, Iietie emlirgy of the with the invention (If the ballistic pendulum in 17-1:3. 1-2