Measurements of Transmission and Attenuation Characteristics of Fluidborne Noise in Fluid Hoses with/without Tuning Cables

The transmission of fluidborne pressure and flow pulsations through a hose assembly is dominated by a four-port transfer matrix equation. The potential of pulsation attenuation in the assembly is then related to the four parameters of the matrix by the concept of “Transmission Loss”. The paper presents the development of an accurate test system, based on the “Four Sensors/Two Systems” method, for measuring the transfer matrix and transmission loss of hose assemblies. Particular attention is paid to the solutions to some technical problems encountered during the development and measurement. Then presented is the application of the system to various types of flexible hose with or without tuning cables used in power steering hydraulic systems. The measurements are very valuable for developing the best tuning cable and hose devices, quieter power steering systems as well as the hoses used similarly in other fluid power systems.