Y/The NSWC Aeroprediction Code has been extensively ipplied to the prediction of static and dynamic aerodynamics '0/ mTisSit configurations.Major extensions have recently been nfiade to the code to extend its capability to 0/,/' M , < 8 and 0P 1 8 0 d and also to improve the tranaonic inviscid ýo'ay alon static aerodynamic predictions and the dynamic derivative predictions for all Mach numbers.The theoretical basis for the code extensions are outlined and previous methods are briefly reviewed.The code is evaluated through comparisons of computational examples with experiment for body alone, body-tail and body-tail-canard configurations.The speed and accuracy of the code are ideal for use in preliminary design.Examples of design applications to specific tactical weapon configurations are presented.-. ('"" INTRODUCTIONA continuous need exists for estimating the aerodynamic characteristics of a wide variety of tactical missile and projectile configurations, especially in the preliminary or conceptual design phase.To meet this need, the Navy (in cooperation with the Army) undertook the development of a rapid, inexpensive, easy to use Aerodynamic Prediction Code in 1971.The code was developed so as to handle fairly general wing-body-tail configurations and hence have direct application to a high percentage of tactical weapon designs. Preliminary versions of the code were published in 1972, 1975, and 1977.The changing mission requirements for both current and future weapons has dictated, however, the need to revise and extend the capabilities of the 1977 version of the Aeroprediction Code, which was limited to M < 3.0 and small angles-of-attack (a < 150), to higher Mach numbers and anglesc-of-attack.The objective of the current effort, which is nearing completion, is to extend the 1977 version of the Aeroprediction Code to M = 8 and a -180@. L" In addition, modification of some of the existing methods due to advances in -J the state-of-the-art and computer program optimization is desirable. 0309 ()62T r-mt -i" bfn upproved 1-39The general approach of the code development has been to combine existing and newly developed computational methods into a single computer program. The basic method is that of component superposition where the body-alone, liftingsurface-alone and interference contributions are added to obtain total configuration aerodynamics.The code development has occurred in four increments. The first thrae of these increments were previously reported, and led to the development of a code capable of determining the aerodynamic coefficients for axisymmetric, non air-breathing configurations with up to two sets of lifting surfaces for low angles-of-attack and Mach numbers to 3.0.The results of the fourth increment, required to meet the stated objective, is the subject of this paper. Program plans for this effort and so e early results were presented at the l1th Naval Symposium on Ballistics. The theorigs used, outlined briefly here, are discussed in more detail elsewhere. ' The resulting code has compu...
necessary to eject electrons continuously during a solar flare in order to maintain the electric field. This could be done with an electron linear accelerator emitting a beam of electrons at the design energy. These electrons could be expected to escape through the magnetic field on account of the relativistic increase in their mass. An allowance for this linear accelerator has been made in the weights quoted in Fig. 1. However, because of the greater simplicity and negligible weight of the inductive charge ejection scheme, it is to be hoped that the accelerator would be unnecessary.It can be seen from the foregoing discussion that the magnitude of the losses that we can expect is at present unknown. Losses take the form of motion of electrons toward the space vehicle or positive ions away from the vehicle, in either case at the expense of the energy of the electric field. Taking first the losses due to positive ions, we note that, since there are no trapped ions in the system, and since ions coming from outside the system (including the solar flare ions) are reflected without loss, the only source is from the ionization of neutral atoms in the electric field region. Following such an ionization, the electron that is born is retained on the magnetic field line where it is, but the ion is simply ejected. The worst case is if ionization takes place at the surface of the vehicle, for then each ion ejected carries with it an energy eF 0 acquired from the electric field. Two possible sources of neutral atoms are outgassing from the surface and micrometeorites. Assuming pessimistically that each ionization is at the surface of the vehicle, Table 2 shows the permissible outgassing rates for two values of the power consumed by the ion current. The outgassing can be seen to represent a serious problem, but it is probably not insuperable since conditions in space are very favorable to achieving a good bakeout of exposed surfaces. The micrometeorite rate near the earth is given by Whipple 5 as about 10~6 g/cm 2 -yr, but evidence obtained in deep space by Alexander, 6 using an instrument aboard Mariner II, showed flux rates 10 4 times lower than corresponding rates near the earth.The remaining source of loss arises from the possibility of diffusive motion of the electrons toward the space vehicle. This source of loss is at present, by many orders of magnitude, the least certain aspect of the whole device. We are attempting here to confine a plasma with a magnetic field; experience gained in the field of controlled thermonuclear fusion prompts us to comment on this problem with extreme caution. We can, however, point out that our configuration having the magnetic field "inside" and the plasma "outside" does fulfill the so-called minimum B requirement presently thought to contribute to stability. 7 Furthermore, certain types of instabilities which might have been expected to contribute to substantial rates of diffusion across the magnetic field, 8 and which are thought basically to be a result of the difference between the mas...
A nonsimilar solution of the incompressible boundary layer over a flat plate in the presence of shear flow is considered. The Dorodnitzyn method of approximate solution, utilizing integral relations, is applied to Crocco forms of the boundary layer equations. Agreement is obtained with the similar solutions of Ting. The computations provide numerical results for the transition between the cases of Li and Murray and of Ting.
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