ДОСЛІДЖЕННЯ ВИМІРЮВАННЯ ХАРАКТЕРИСТИК ПОТОКУ У ВИХРОВИХ КАМЕРАХ НАСОСІВ З УРАХУВАННЯМ ВПЛИВУ ІНСТРУМЕНТА НА ПОТІК

The study quantifies how a measuring probe perturbs the internal flow of a vortex chamber pump (VCP) and affects its integral energy metrics. CFD simulations were performed in ANSYS CFX using the RANS SST turbulence model; both steady and unsteady runs on unstructured meshes were executed with strict convergence and near‑wall quality controls. Probe locations included the end cover (for several relative diameters) and the lateral wall of the chamber. The impact was evaluated using meridional and horizontal velocity fields, speed‑difference maps versus the baseline (no probe), λ2‑criterion iso‑surfaces, and turbulence intensity distributions. End‑cover ports practically do not alter the pump's energy parameters: the efficiency and flow rate deterioration stay within ≈ 5 % across a wide range of relative probe diameters, i.e., within typical experimental uncertainty. In contrast, lateral mounting induces strong flow asymmetry, local turbulence intensity amplification, and a marked efficiency drop; in the worst case, the efficiency decreases to 0.32 of the baseline. The principal systematic measurement bias concerns the tangential (swirl) velocity component: fluid inside the probe channel does not rapidly acquire the main flow's angular speed rapidly enough, leading to locally underestimated readings. To minimize interference, we recommend: placing the probe in the end cover, limiting its relative diameter to ≤ 0.25 of the throat, and orienting the sensor standard to the measured velocity component. These results clarify the conditions for representative contact measurements in VCPs and support the design of experiments and correction procedures for CFD-experiment comparison.