Many energy recovery, drive cycles (Organic and Steam Rankine cycles) and rocket propulsion cycles require the use of a turbine that operates at low volumetric flow and high-pressure ratio. Additional requirements include low cost, reduced weight, and reduced axial length (for robust rotor dynamics).

Many gas turbines with radial compressors utilize a radial-to-axial inlet duct upstream of the first compressor stage. Aside from the fact that flow in the duct generates aerodynamic losses, the flow profiles at the duct exit, delivered to the inlet of the first impeller, also affects the performance of the compressor. 

The Value of Visualizing Velocity Vectors

by Mark R. Anderson on Nov 9, 2017 11:12:39 AM

Beyond being a fun tongue twister, visualizing the velocity vectors is probably the most useful and intuitive information available in turbomachinery design. Many fundamental parameters can be gleaned directly from these triangles. These include: flow coefficient, work coefficient, stage reaction, de Haller number, diffusion factor, and diffusion ratio, to name just a few. A great many design rules are predicated on these parameters in the initial design process, which is generally geared to target velocities as the starting point, rather than a predetermined geometry.


New engine development is a costly endeavor and making the right decisions early in the engine design is extremely important. It requires multi-disciplinary consideration of the engine thermodynamic cycle coupled with preliminary aerodynamic design of key engine components. This includes evaluation of size, weight and cost parameters, with constraints imposed by aero, structural, geometrical, manufacturing, and material requirements.

Arbitrary blade section profiling is an essential part of designing high performance axial turbines and compressors. In most cases such blade section models are formed by hybrid use of arbitrary curves and blade section parameters, such as blade angles, chord, sizing of edges, wedge angles etc. Hybrid blade section models deliver to the design  process  both convenience and flexibility of controlling section geometry.

Throughflow Modeling: An Overview

by Morgan Williams on Mar 22, 2017 4:08:25 PM

This Blog post gives a brief outline of the throughflow method for turbomachinery flows and presents the calculated performance results of a Single-Stage Axial-Flow Compressor validation.

Expanding design capabilities for advanced high-performance turbines for steam and organic Rankine cycle power generation is a constant area of focus in developing Concepts NREC’s Agile Engineering Design System ® (AEDS) software.

Cycle and operation requirements, as well as a wide range of operating conditions and volumetric flows, are often required for the design of turbines with diverse geometries. Some typical design tasks and available new/existing features within AEDS are described here.

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