Turbomachinery

Turbomachinery devices are found in many applications from different industries as fans, pumps, propellers, compressors and turbines. Our customers take advantage of the tools and solvers available in both HELYX and HELYX-Coupled to characterise the flow through these devices.

Our CFD products offer several methods to predict the effects of rotating components, depending on the circumstances and the accuracy required. For basic calculations, the effects of a fan or propeller can be approximated using a simple actuator disk model. For steady-state flows, the forces exerted by the rotating component can be calculated using the multiple reference frame (MRF) approach. Finally, for maximum accuracy in transient solutions, rotation can be explicitly solved using a rigid-body mesh motion model.

Regarding flow characteristics, it is convenient to make the distinction between low-Mach and high-Mach turbomachinery devices to understand the actual applications.

Devices such as pumps, water propellers, fans, wind turbines and hydraulic turbines usually operate in the low-Mach number regime. As a result, the flow through these devices can be accurately represented using incompressible flow solvers. The HELYX-Coupled add-on for HELYX offers the best solver for incompressible, iso-thermal flows in terms of accuracy, robustness and convergence speed (in comparison to equivalent segregated solvers).

HELYX and HELYX-Coupled are used by some of the largest water pump manufacturers in the world to design their latest products. The software is also used in production to design state-of-ther-art propellers and propusion systems for marine applications.

Ship Propeller Simulation with HELYX.

For turbomachinery components operating in the high-Mach number regime, ENGYS provides an improved compressible flow solver in HELYX valid for Mach numbers approaching unity. The typical applications falling in this category include compressors, gas turbines and steam turbines. High-speed rotating machinery can also be modelled with this solver to predict windage losses and temperature effects due to high friction.

HELYX is currently used by a well-known manufacturer of gas turbines to predict machine performance and aid with the design of the blade cooling passages. In this sense, the compressible solver methods can be used in conjunction with our single-matrix conjugate heat transfer (CHT) solver to provide the temperature distribution in the turbine blades.

CFD simulation of Aachen Turbine with explicit rotation in HELYX (courtesy of IST at RWTH Aachen).