A Vibration Test Stand for a Thermal Systems Laboratory

This report documents our experience developing a novel test stand for a thermal systems laboratory. The laboratory is the Texaco Energy Systems Lab at the Mechanical Engineering Department of Penn State. This lab was conceived to help engineering students appraise the integrating nature of the design activity. Among other test stands, the lab has an instrumented 1C engine. The level of instrumentation allows an energy balance on the engine, and computation of magnitudes such as volumetric and thermal efficiency. Vibration elimination or absorption has important consequences for product life and appeal. Thus, an identical engine, externally driven, was mounted on a specially designed base of variable stiffness. In this engine, valve and piston displacement can be monitored via accelerometers. The base displacement as function of time can be captured via an LVDT sensor. Analysis of the data allows determination of two dominant frequencies, and of the corresponding phase angle.