Hydraulic Library User Manual - NUPET

Hydraulic Library 4.2User ManualNone of these line submodels take friction into account. We will suppose that therelief valve is close to the node but the pump and the motor are at such distancesfrom the node that the pressure drop along the pipes cannot be ignored. We needto select new pipe submodels that take friction into account for the pipe runs fromthe pump to the node and from the node to the motor.2. Click on the line run attached to the pump and select HL03 in the Submodel list.Figure 1.19: The hydraulic line submodels available.Note the brief description of each line submodel. In thesedescriptions C stands for compressibility, R for resistance(pipe friction) and I for inertia (fluid momentum). HL000which we used before takes into account compressibility only.HL03 takes into account compressibility and friction. It ismodeled like two hydraulic compressible volumes with aresistance between them.Why did we not choose a more complex submodel that also included inertia?We answer this question later in this exercise.3. For the line from the node to the motor, select the submodel HL01.4. For the line between the node and the relief valve, the submodel DIRECT isalready selected and this is exactly what we want.Step 2:Set parameters and run a simulation1. Go to Parameter mode and set parameters for HL01 and HL03 so that bothpipe lengths are 5 m and pipe diameters are 10 mm.This can be done one at a time. However, we can do it another way. Press theShift key on click on the HL03 and HL01 line runs so that they are selected. UseParameters Common parameters. Figure 1.20 shows the Commonparameters dialog box.17