Advanced Fluidic Controls for Integrated Propulsion Systems. Part 5. Reliability Study of an Integrated Propulsion System Control Using Fluidic Control Techniques

摘要

A reliability study of the fluidic Integrated Propulsion Control was conducted. Since there was essentially no reliability precedence in the fluidics area, the program was developed through the application of current reliability techniques to fluidics. This study resulted in an estimated reliability of 3360 hours mean-time-between-failure (MTBF). This is approximately 3.5 times that estimated for an equivalent hydromechanical of electromechanical control system. In addition to the reliability estimate, a failure effects/fail safety analysis was conducted at the subsystem level. Several critical or potentially critical failure modes were uncovered. Also several reliability tests of fluidic components were conducted. These included life tests and contamination tests. Maintenance free operation in excess of 15,000 hours is indicated by the life tests. The contamination tests indicate that if contamination levels are maintained at less than 1.0 mg per cubic foot of air (about 20 times the level of normal air) that the performance of the amplifiers of the size used in the control system would not be degraded. (Author)