## Nomenclature \begin{tabular}{l l} Symbol & Description & Unit \\ A & Center distance & [m] \\ B & Gear width & [m] \\ R & Gear pitch circle radius & [m] \\ \(R_{a}\) & Radius of toothed apex & [m] \\ \(\beta\) & Helix angle & [\({}^{\circ}\)] \\ \(De\) & Diameter of tooth tip & [m] \\ Z & Tooth number & \\ n & Rotation speed & [r/min] \\ \(G_{k}\), \(G_{b}\) & Turbulent kinetic energy & [kg/(ms\({}^{3}\))] \\ \(\mu_{t}\) & Turbulent viscosity & [Pa \(\cdot\) s] \\ \(C_{1c}\), \(C_{2z}\), \(C_{\mu}\), \(\sigma_{k}\), \(\sigma_{\epsilon}\) & Empirical constant \\ \(k\) & Turbulent kinetic energy & [m\({}^{2}\)/s\({}^{2}\)] \\ \(\varepsilon\) & Flow energy dissipation rate & [m\({}^{2}\)/s\({}^{2}\)] \\ \(f_{v}\) & Mass fraction of vapor & \\ \(f_{g}\) & Mass fraction of air & \\ \(v\), \(v_{r}\) & Fluid velocity, fluid surface velocity & [m/s] \\ \(D_{f}\) & Vapor diffusion coefficient & [m\({}^{2}\)/s] \\ \(\sigma_{f}\) & Turbulent Schmidt number & \\ \(R_{e}\), \(R_{e}\) & Vapor generation rate, gas phase condensation rate & \\ r & Bubble radius & [m] \\ \(\sigma\) & Surface tension coefficient & \\ P & Pressure & [MPa] \\ \(P_{v}\) & Saturated vapor pressure & [Pa] \\ \(p\), \(\rho_{v}\), \(\rho_{g}\), \(\rho_{l}\) & Density of gas-bearing fluid, density of steam, density of air, & [kg/m\({}^{3}\)] \\ \(V_{g}\) & Gas volume fraction & [m\({}^{3}\)] \\ \(V_{s}\) & Cavitating region volume & [m\({}^{3}\)] \\ \(V_{t}\) & Volume of gear pump cavity & [m\({}^{3}\)] \\ \(\eta_{v}\) & Volumetric efficiency & [\%] \\ \(Q_{a}\) & Actual average discharge rate of pump & [L/min] \\ \(Q_{t}\) & Theoretical average pump outlet flow & [L/min] \\ \(V\) & Theoretical flow rate of gear pump per revolution of pump & [m\({}^{3}\)] \\ T & Time period for one complete rotation of gear pump & [s] \\ \end{tabular}   
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