On the kinematics of the head using linear acceleration measurements.
Abstract The paper deals with an application of the nine accelerometer scheme proposed by Padgaonkar et al. (1975) to the analysis of the head kinematics including the head angular acceleration and velocity using linear acceleration measurements. The computed results have been compared with the film analysis and with the actual measured quantities in the case of the dummy experiments. The study reveals an excellent agreement among these results and indicates the feasibility of the application of the method to biomechanical studies.
Torque versus Angular Displacement Response of Human Head to -Gx Impact Acceleration
This paper discusses the results of a comparison of 41 previously reported test runs and human volunteer runs run by Mertz and Patrick in testing torque versus angular displacement response of the human head to -Gdx impact acceleration. Due to different instrumentation and measuring techniques, there were several differences, but large portions of the data were comparable. The paper points out the need for anatomically based three-dimensional coordinate systems to permit quantitative comparisons between human subjects.
THE PERFORMANCE OF STEADY DETONATION ENGINES
Propulsion systems driven by steady normal detonations are studied. The practical di‐culties associated with stabilizing a detonation wave are highlighted. The requirement on the freestream total enthalpy is considered in parallel with efiects such as condensation or auto-ignition of the fuel-air mixture and limitations associated with fuel sensitivity to detonation. A criterion for detonation stabilization is formulated and applied to an analytical treatment of a detonation ramjet and a detonation turbojet, which are the respective analogs of the ramjet and the turbojet using detonative combustion. The performance of these engines is evaluated and compared to the ideal ramjet and turbojet models for hydrogen and JP10. A limitation is placed on the maximum total temperature allowed in the combustor, based on material considerations. The results show that steady detonation engines have a small thrust-producing range, due to the requirements for detonation stabilization. Their performance is always lower than that of the conventional ramjet and turbojet because of the total pressure loss across the detonation.