Performance v. Durability: The Eternal Turbomachinery Design Grudge Match

by Steve Kohr, Director of Software Product Management & UX on Nov 12, 2021 11:00:00 AM

It is not a secret that when designing turbomachinery components there is a trade-off between the performance and durability. I challenge any aero or structural designer to highlight a geometric parameter, that when modified, is beneficial for both. Because of this trade-off, designers are often faced with the dilemma of selecting reduced performance or life when finalizing a component design. But which one should be sacrificed for the benefit of the other? This brings us to the all-important question: What is more important in turbomachinery design: performance or durability?  

Which Type of Turbomachinery is Aerodynamically Easier to Design, a Compressor or Turbine?

by Daniel V. Hinch, Corporate VP Sales and Marketing, Concepts NREC on Oct 29, 2021 2:00:00 PM

In the world of aerodynamics, there are several branches and sub-branches of different types of aerodynamics. In the big picture the field of aerodynamics can be broken down into external and internal aerodynamics.   External aerodynamics is thought of external flow around an isolated body, with the typical example being flow around an aircraft wing section, or perhaps around an automobile. There is typically a far field ambient condition, with an isolated body moving through the field (or you can view it as the fluid moving over the body). Internal aerodynamics is thought of as a flow moving through some confined space or passage, with a prime example being flow through turbomachinery, such as a compressor or turbine. There are other ways to classify aerodynamic flow, such as subsonic flow (Mach No. <0.8, including low Mach No. incompressible flow, say Mach No. <0.3), transonic flow (around Mach No. = 1, say 0.8 to 1.2), supersonic flow (Mach No. > 1.2), and even hypersonic flow (Mach No. >5). Turbomachinery design encompasses the first three types of flow regimes, subsonic through supersonic. So in general, turbomachinery aerodynamics is predominately internal flow, over a range of Mach Numbers.    

Heavy Interest in the Lightest Element: Hydrogen

by Mark R. Anderson, CTO of Concepts NREC on Oct 1, 2021 11:00:00 AM

It’s always interesting to look at the topics of my favorite engineering conferences and see what’s in vogue in a given year. What jumped out at me this year at the ASME TurboExpo was the hot topic of hydrogen.

Meet Claudio Raia

by Kate Guerrina, Marketing Manager on Sep 17, 2021 11:00:00 AM

Dave Schowalter, Director of Global Software Sales, introduces you to Claudio Raia, our newest team member and the Managing Director of Concepts NREC Europe. Welcome Claudio!

To The Question of sCO2 Compressor Upstream Conditions Selection

by Oleg Zubalev, CAE Software Design Engineer on Sep 10, 2021 10:00:00 AM

The compressor is generally one of the most sensitive components of an sCO2 cycle. This makes it a challenge to design a robust compressor while keeping the thermodynamic cycle close to optimal.

Preliminary Design Considerations of Zero Reaction Stages in Turbines

by Oleg Dubitsky, Distinguished Corporate Fellow, Director of Corporate Technology on Aug 27, 2021 11:00:00 AM

Low reaction stages are often used as control stages of steam turbines, ORC turbines,  drive and rocket turbopump turbines. Some of the benefits of low reaction stages vs higher reaction stages are:    Smaller radial size (and weight) for the given power and rotation speed  Compatibility with use of partial admission, which is used to accommodate low volumetric flow, with the needed low pressure gradients in the rotor blades to reduce leakage penalties  Both above factors allow increasing of nozzle and rotor blade heights  Smaller radial size provides lower disk rim speeds and disk stresses  Low reaction generally means lower axial thrust of the rotor  Velocity stage configurations are possible for low reaction designs (Curtis stage for example, Fig.1). Velocity stages allow further reduction in radial size and increasing blade heights 

What Are the 5 Axes in 5 Axis Machining?

by Christos Maninos, CAM Application Engineer & Peter Klein, Director, CAM Software on Aug 13, 2021 4:00:00 PM

What is 5 axis machining? In short, it is manufacturing a component on a CNC milling machine that can travel in 5 different directions. These machines allow the cutting tool to reach around parts with a high degree of freedom. This makes them ideal for milling the complex shapes of turbo machinery components.
For lower thrust rocket engine designs, either a Gas Generator (GG) cycle or a Dual Expander (DE) cycle can be considered, among others. While each of these cycles has its inherent advantages and disadvantages in an overall sense, each cycle requires a different approach to the turbopump assembly (TPA) design. This blog presents a general summary of advantages and disadvantages of each of these cycles, and obviously applies when the engine thrust level is low enough that a DE cycle can even be considered (less than about 50,000 lbf of thrust). This summary is not exhaustive and focuses primarily on the TPA, but provides information to help decide which cycle to use.

Use of Optimization in Turbomachinery Design Process

by Akshay Bagi, General Manager, Concepts NREC India Private Limited on Jun 4, 2021 11:00:00 AM

Introduction: With the advancements in computation power, optimization is not just limited to academics and research anymore. It can now be realistically used for industrial designs. There are several optimization software available in the market which utilize various powerful optimization techniques but not every software can be practical for industrial applications. This is especially true for the turbomachinery industry. Turbomachinery design is coupled with aero and mechanical optimization. The problems are highly constrained and usually involve non-linear functions. The optimization algorithm needs to be efficient to handle such problems.

How Many Pieces of Turbomachinery (Fans, Blowers, Compressors, Turbines, Pumps) Do You Have in Your House? Part 2

by Daniel V. Hinch, Corporate VP Sales and Marketing, Concepts NREC on May 14, 2021 11:00:00 AM

In my last blog I wrote about visiting a local middle school to give a talk on ‘What is Turbomachinery, and How Does It Work?’   The quiz at the end of the talk was for the students to list all the turbomachinery in their home. I had a few examples in mind to get the list started but was impressed with how long of a list we were able to generate after the students thought about it for a while. Since then the list has grown to include 40 items.   I will present those 40 below, but first let me repeat the assignment and the ground rules to see if you can think of more:   List every piece of turbomachinery in your home. Inside and outside (in your yard is OK). Positive displacement equipment is OK to list. Don’t include turbomachinery in your cars or any vehicle or wheeled yard equipment (that’s another list…)
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