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The results of recent dynamic load measurements on human skull and patella bone, conducted with less-than-1-sq-in. penetrators, are discussed in relation to previously reported skull impact data from larger contact areas. These medical data are compared to the dynamic response of a large variety of natural and synthetic plastic materials, for use in trauma-indicating headform and kneeform design. Several bodyform designs are proposed as research tools.

The presentation here of a computer program simulating an engine cycle emphasizes mechanical factors under the control of the engine designer rather than scientific aspects of combustion. Data secured by measuring valves, manifolds, and other parts on a flow bench are used to calculate instantaneous flow in and out of the cylinder for the firing engine. Heat transfer, finite time of combustion, and variable specific heat of the gas are also calculated. The program is particularly well adapted to indicating the direction and relative magnitude of the effect of changing one variable, such as valve size, at a time.

RUMBLE is a low-frequency noise heard in high compression engines and accompanied by high rates of pressure rise. Thus, rumble indicates a rapid combustion process. This paper describes a method of studying this problem: by detection of flame fronts by ionization gaps. Results of experiments show that rumble is caused by deposit ignition in the end-gas region. These multiple ignitions occur after the normal flame front has progressed partially across the chamber. The authors conclude that this type of deposit ignition is generally a self-sustaining process, lasting until the deposits are burned out at a particular engine performance level. When the level is increased, the process repeats itself.

THIS paper describes the development and utilization of a new Ford free-piston power-plant, the model 519. Mr. Noren traces the development of the engine from the initial idea to the point where commercial utilization could be considered. Mr. Erwin describes one commercial use: in the Typhoon tractor. The ratio of size and weight to horsepower is favorable for farm tractors, being smaller and lighter than equivalent diesel engines. The performance of the tractor has been satisfactory thus far, operating smoothly and being practically vibration-free, with little noise. The advantages of the free-piston gasifier, as reported by the authors, are: flexibility, fuel economy, no need for auxiliary starting engine, economical manufacture of a wide range of engine sizes, adaptability to a wide range of fuels, and good torque characteristics.