Regenerator. Regenerators provide detection and retransmission of Ethernet signals and are used to provide service when the distance to an Ethernet switch exceeds otherwise applicable design limits. The Telephone Company will determine whether regenerators are needed and what transport medium and equipment will be used to provide regeneration. Regenerators are available on a per-port basis and are available for 100 Mbps, 1 Gbps and 10 Gbps ports.
Regenerator. EPP monthly rates, non-recurring charges and Term Extension MTM Rates apply to Regenerators, as applicable.
Regenerator. The objective of this activity is to develop experimental facilities and experimental methodologies for the characterization of regenerator samples with different geometries, characteristic dimensions and made out of different materials. The results are to be expressed using dimensionless parameters, to formulate the regenerator design rules.. An ideal regenerator has perfect thermal contact with the gas (thermal time constant = 0), has a low pressure drop and a low axial thermal conductivity. Accordingly, three types of tests are used to characterize regenerators: (1) thermal time constant () measurements; (2) flow resistance measurements; and (3) thermal conductivity measurements. Thermal time constant measurements The setup used is shown in Figure 2. The mean pressure can be varied from 1 to 40 bar. The working gas is helium. The excitation frequency of the acoustic driver can be varied from 20 to 120 Hz. The valves that are visible in Figure 2 are used to obtain the right phase relationship between pressure and velocity at the regenerator. Figure 2 Experimental apparatus for determining the time constant of the regenerator material Different samples of regenerator materials were tested. The commonly used woven metal screens varied from mesh number 30 to 200 (meshes/inch). In addition, a needle array regenerator was tested. The results clearly show that the values of strongly depend on the velocity, see Figure 3. A higher velocity leads to a lower in the regenerator. It can also be found that the length of the sample affects the measured values. A long length leads to a higher value of for the same test conditions. 180# 200# 94 # 45 # Needle Array P=25 bar, f=30 Hz 0.8 0.6 0.4 0.2 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 u1 (cold end) (m/s) Figure 3 experimental results Flow resistance measurements The friction factor in the regenerator can be determined by measuring the pressure drop and the average velocity at which the fluid is passing through the regenerator. Historical data for porous media are available from measurements of Xxxx and London. Swift & Xxxx fitted these data into correlations, that are often used in thermoacoustic design codes. The experimental apparatus comprises of a 3 m long PVC pipe connected to the high pressure air supply via an adjustable valve that controls the air flow rate, shown in Figure 4. Figure 4 Schematic diagram of the flow resistance measurement rig The obtained correlations are summarize...
