A relatively simple theoretical model of near-surface pressure pulse propagation from nuclear explosions is developed from the hypothesis that the early portion of the pulse travels in the real atmosphere's counterpart of Lamb's edge mode. Various concepts of geometrical acoustics are used in the construction of the model. The pulse travels along horizontal ray paths which may be refracted by horizontal variations in the height-averaged effective sound speed and wind velocity. The dispersion of the pulse as it propagates along such paths is governed by a onedimensional wave equation similar to that derived by Korteweg & de Vries in 1895. Coefficients are found by comparison with the dispersion relation derived by Garrett in 1969 as an expansion in terms of a parameter E describing deviations of the atmospheric profile from isothermal. The method of incorporation of terms governing accumulative far-field non-linear effects is indicated. Height variations in propagating variables are approximated to zeroth order in E. Variations along horizontal ray paths are governed by the principle of conservation of modal wave action. The excitation of the edge mode is found by matching the general form of the far-field quasi-geometrical solution to the near-field solution for a point energy source in an isothermal atmosphere. Explicit expressions are given for the far-field pressure disturbance. Computations agree favourably with those based on a multimode theory for the first few cycles of the waveform. The edge mode theory leads to a number of implications, which may be compared with existing data. These include the prediction that the energy of the explosion yield may be estimated from a knowledge of the first peak-to-peak period and first peak-totrough pressure amplitude in far-field records with very little information concerning atmospheric structure, and the prediction that anomalous azimuthal variations in waveform amplitudes may be caused by focusing or defocusing of horizontal ray paths for the edge mode.

These authors have recognized some common errors but committed others in interpreting explosion source wave data. In result, their assumed source and propagation model may have distorted their conclusions, so that the impact of their elegant wave calculation is lost. Their treatment of The E#ect• o] Nuclear Weapons (ENW) [Glasstone, 1957], seems unwarranted and inconsistent. They mention 1957 and 1962 editions in the text, but show

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An acoustical field theory for axisymmetric multisectioned duct liners is combined with a numerical minimization algorithm to predict optimal one- and two-sectioned liner configurations producing maximum sound attenuation. Optimal inlet liner impedance properties calculated by this method are presented for a research compressor operating at about 0.4 Mach number. Kemp-Sears theory is used to describe the rotor/stator viscous wake interaction effects. Comparisons with data presented for point and plane-wave sources indicate that optimal liners for complex turbomachinery sources cannot be easily inferred from data based on these simpler source models.