INVESTIGATION OF THE OPERATIONAL CHARACTERISTICS OF TORQUE-FLOW PUMPS WITHIN THE OPERATING RANGE Q = 0.7–1.2 Qnom

Abstract

This study presents a numerical investigation of the operational characteristics of the torque-flow pump TFP 80-32
within the flow rate range Q = 0.7–1.2·Qnom, which corresponds to typical conditions of long-term pump operation. Based on
the geometric parameters of the pump, three-dimensional models were developed and a CFD analysis was carried out in ANSYS
CFX using the k–ε turbulence model. Two types of impellers were considered: one with six curvilinear blades and a dual-tier
impeller with twelve blades.
The obtained characteristics demonstrated that, within the operating range, both designs provide a stable, gently
declining head curve and comparable hydraulic efficiency values (up to 48.3% for the six-blade impeller and 47.5% for the
dual-tier impeller). At the same time, the dual-tier configuration ensures an increase in head by 1.3–1.8 m (3–5%) without a
significant decrease in energy efficiency. Analysis of velocity and pressure fields showed that the dual-tier impeller provides
more uniform flow distribution onto the blades, reduces channel diffusivity, and decreases vortex losses in the free chamber.
The results of the study justify the choice of impeller design depending on the operating conditions: the six-blade
impeller is more suitable for regimes close to the nominal point, while the dual-tier impeller ensures an additional head margin
and greater operational stability at higher flow rates.