To measure the pressure on the bottom of the piston (load pressure), two pressure gauges were used, one under the piston and another above the sandstone core.
5 days after insertion of the piston, when loading was normally to be started, the marrow pressure was measured before and after a 1.2-mm diameter hole was drilled through the bone under the piston, into the marrow cavity.
The new design had some potential of intensifying improvement from the view point of piston thermal load.
Normal stress is applied to the sample, in excess of the pore fluid pressure (P f ) measured in the vessel, via a pressure-compensated upper loading piston, so that the effective normal stress (σneff) is equal to the axially applied stress (see Den Hartog et al. 2012a).
Piston rod gas load is the varying, and usually reversing, load imposed on the piston rod and crosshead during the operation, by different gas pressures existing on the faces of the compressor piston.
The third is the precise measurement of the volumetric strain through the displacement of axial and radial loading pistons.
A custom-built test rig was used, in which a section of piston ring is loaded against a reciprocating, laser-textured, fused silica pad representing the liner.
Key system design and operating parameters such as piston mass, external load, and heat input are varied to identify conditions and trends for optimal performance.
The maximum piston rod gas load is determined for each compressor by the manufacturer, to limit the stresses in the frame members and the bearing loads in accordance with mechanical design.
Key design features are identified that reveal FPE efficiency, operating frequency, and output power are dependent on piston mass, external load, input heat-rate, and duration of heat input.
