This blog post will show an example of a pump design task for a specific application, using the AxSTREAM® pump design and analysis code. Centrifugal pumps are designed to meet the requirements of head rise at the discharge, while at the same time the suction performance at the pump inlet must be free of cavitation over the entire operating range. This requirement places an additional constraint on a successful pump design and a good example of AxSTREAM® capabilities.
Pump Installation and Performance Requirements
The pump installation is illustrated in Figure 1. The pump will suck water from the bottom of a reservoir and discharge into a raised tank that is 145 feet above the pump. The pump should be designed for optimum efficiency and will be driven by a variable speed electric motor. The design flow rate is 2,000 gallons per minute (GPM) and it must operate free of cavitation at all operating points.
The key performance goals and requirements for the pump are summarized below:
Pumped liquid: water
Density, ρ: 62.3 lbm/ft3
Volume Flow rate: 2,000 GPM
Inlet Temperature, Tt1: 527.7 Rankine
Vapor Pressure, Pv: 0.46011 psi
Static Head Rise: 145 feet
Design and analysis approach
Using AxSTREAM Preliminary Design Solver, thousands of flow path geometries can be generated that satisfy the user defined boundary conditions and geometric parameters within given constraints. By determining key parameters such as suction cavitation performance early at the beginning of the design process, users can minimize development cost while maximizing the pump efficiency. In addition to being able to generate the optimum flow path and pump blades to meet the design point goals, users can also analyze off-design operating conditions for the pump in a system environment that can have changing boundary conditions, thus placing different requirements on the pump.