@ARTICLE{Ułanowicz_L._The_2020, author={Ułanowicz, L. and Jastrzębski, G.}, volume={68}, number={No. 4 (i.a. Special Section on Advances in Electrical Power Engineering)}, journal={Bulletin of the Polish Academy of Sciences Technical Sciences}, pages={949-956}, howpublished={online}, year={2020}, abstract={One of the little described problems in hydrostatic drives is the fast changing runs in the hydraulic line of this drive affecting the nature of the formation and intensity of pressure pulsation and flow rate occurring in the drive. Pressure pulsation and flow rate are the cause of unstable operation of servos, delays in the control system and other harmful phenomena. The article presents a flow model in a hydrostatic drive line based on fluid continuity equations (mass conservation), maintaining the amount of Navier-Stokes motion in the direction of flow (x axis), energy conservation (liquid state). The movement of liquids in a hydrostatic line is described by partial differential equations of the hyperbolic type, so modeling takes into account the wave phenomena occurring in the line. The hydrostatic line was treated as a cross with two inputs and two outputs, characterized by a specific transmittance matrix. The product approximation was used to solve the wave equations. An example of the use of general equations is presented for the analysis of a miniaturized hydrostatic drive line fed from a constant pressure source and terminated by a servo mechanism.}, type={Article}, title={The analysis of working liquid flow in a hydrostatic line with the use of frequency characteristics}, URL={http://www.czasopisma.pan.pl/Content/117273/PDF/30_949-956_01573_Bpast.No.68-4_27.08.20.pdf}, doi={10.24425/bpasts.2020.134191}, keywords={aviation, unmanned aerial vehicle, hydrostatic drive, servomechanism, hydrostatic line}, }