Profiler & 3D Blade Design Capabilities – AxSTREAM^®

Introduction

Whether the geometry comes from the AxSTREAM^® Preliminary Design tool or imported from a CAD model or cloud of points through the AxSLICE® module blade profiling plays a crucial role in the performance of a machine both aerodynamically and structurally.

Both the Axial Profiler and Blade Design and the Radial Profiler and Blade Design of the AxSTREAM^® platform are presented in this page, respectively, and are licensed individually.

The Axial Profiler and Blade Design of the AxSTREAM^® platform allows users to design 3D blades for axial turbines, axial compressors and axial fans through different profiling modes.

The AxSTREAM^® Radial Profiler and Blade Design allows users to easily design and edit rotor, stator and splitter blades for radial compressors, diagonal compressors and radial turbines.

Each blade can be profiled for each of up to 49 spanwise sections using different profiling modes to ensure maximum editing flexibility and guarantee performance. Profile properties for each section can be reviewed and edited to provide optimum designs for the given flow conditions stored in the AxSTREAM^® project database.

Once designed or edited blades geometry (axial only) can be stored to the ATLAS profile database and/or exported as X, Y coordinates. On the other hand any blade can be used in the other AxSTREAM^® modules like AxSTRESS or AxCFD for 3D analyses or exported to external software as CAD models.

Axial Blade Profiling Capabilities

Blades of axial machines can be pretty complex and can range in height from a few millimeters to more than one meter (~3 feet). Depending on the blade size, performance to achieve, manufacturing capabilities and cost different technologies can be used and are available in AxSTREAM^®; prismatic (cylindrical), twisted blades, lean (including box), sweep, etc.

An interactive and user-friendly editing allied with a potential flow solver allow instantaneously reviewing flow parameter contours upon changes to the profile geometry to ensure optimum flow in the blades channel.

Furthermore, an optimization of profile for minimization of losses using user-defined ranges of geometric parameters can be set up to deepen the manual optimization performed.

Once each section has be successfully profiled these can then be stacked to fully define the blade geometry in 3D and allow for lean (direct and compound like bow lean for example) and sweep to be included for any stacking axis.

Axial Blade Profiling Post-Processing

To quantitatively and qualitatively evaluate the performance of a profiled 3D blade several options exist. These include the calculation of profile losses, representation of the blade loading, information about separation criteria, Mach number on the pressure and suction sides, etc. which can include results for different airfoils for comparison purposes.

On the mechanical side, estimations of blade stresses at different locations are available to reduce iterations between blade design and 3D structural calculations like in AxSTRESS.

A quasi-3D CFD (cylindrical spanwise section) tool using viscosity and turbulence with customizable mesh allows calculating and displaying heat flux and velocity vectors in inter-blades channel. This Cascade CFD is very useful for transonic stages profiling, where the potential flow cannot predict all effects accurately.

Blade restaggering can also be performed to study how the throat area gets affected to allow for more or less flow rate. This restaggering can even be optimized based on the rotation speed.

 

 

 

 

 

 

 

 

Radial Blade Profiling Capabilities

Profiling of the 3D blades is done through inlet and outlet geometric parameters, beta, theta and channel thickness distributions for each of up to 49 spanwise sections while providing interactive and automatic visualization of the changes on the blade geometry while recalculating the outlet flow angle.

Moreover, editing of the number of blades, blade metal angles, LE/TE angular offsets are possible with the possibility for blade lean and sweep.

Different profiling modes are available to ensure flexibility of the geometry editing for 3D blades, ruled-surface (for impellers) and prismatic (cylindrical) blade for vanes.

Radial Blade Post-Processing

The post-processing includes an interactive display of the blade curvature ensures obtaining a smooth surface which helps prevent flow separation and losses. Several options for leading and trailing edges exist: cut-off, circular or elliptical to fit the desired needs. Additionally, a polar view of each spanwise section of the blade allows users to review the blade profile and make desired changes.

Furthermore, blade restaggering can also be performed to study how the throat area gets affected to allow for more or less flow rate. This restaggering can even be optimized based on the rotation speed.