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Turbomachinery equipment is generally segmented based on whether it extracts energy (e.g., turbines) or adds energy (e.g., pumps and compressors). The addition of energy is usually used to compress or move a fluid. When the fluid is a gas, the turbomachinery equipment is typically referred to as a fan, blower or compressor. This blog will explore the differences between these three devices and where they are used.  

How to Design a Wind Turbine Rotor

by Kerry Oliphant on May 31, 2019 10:08:07 AM

In my previous blog post, “How the Design of a Wind Turbine Differs from other Types of Turbines”, I showed that the very small pressure drop across the rotor makes wind turbine design different from other types of turbines. This blog will focus on the best method to design a wind turbine rotor based on the fact that only kinetic energy is available to extract from the wind.

The Ultimate Fluid Model: Non-Equilibrium Modeling

by Mark R. Anderson on May 24, 2019 10:42:37 AM

In this blog series, I covered a lot of thermo-fluid options in engineering analysis, from the simplest perfect gas (When Perfect is Good Enough – Perfect Gas Models) and ideal liquid, (Fluid Modeling: Liquified ) to much more complex approaches (Going Through a Phase – Modeling Phase Change with Cubics) and (Getting Real – Advanced Real Gas Models). In this blog, I’ll cover the ultimate in thermo-fluid modeling: non-equilibrium modeling. It's rare and expensive, sort of like the Schorschbrau’s Schorschbock 57, a beer that sells for $275/bottle.

The Tesla Turbine – A Solution Looking for the Right Problem

by Barbara Shea on May 17, 2019 8:20:44 AM

The great engineer, Dr. Nikola Tesla, is best known for his work with alternating current (AC) electricity, but, did you know that he patented a bladeless type of turbomachinery in 1913? Called the Tesla Turbine, he developed it while trying to make an engine that was light enough to power his ultimate goal of building a “flying machine”. Tesla-type turbines can also be referred to as multiple-disk, friction, shear-force, or boundary layer turbomachinery.

Fluid Modeling: Liquified

by Mark R. Anderson on May 10, 2019 10:30:23 AM

Continuing on the topic from my previous blog, Getting Real – Advanced Real Gas Models, the counterpart to the perfect gas model for liquids is the “ideal liquid” model.  The ideal liquid model is very simple and is defined as:

 

            Density = constant

            Specific heat = constant

            Sonic velocity = constant

            Viscosity = constant…. or a simple temperature function

 

Getting Real – Advanced Real Gas Models

by Mark R. Anderson on May 3, 2019 10:28:59 AM

The Refprop program

The calculations in the National Institute of Standards and Technology (NIST) Refprop program are generally considered the most accurate thermo-fluid models available.  The routines are widely used in many applications. 

 

The models

Several different models are embedded in the Refprop formulation. The most important are the  Benedict-Webb-Rubin equations of state for the pressure-temperature-density relationship. 

Going Through a Phase – Modeling Phase Change with Cubics

by Mark R. Anderson on Apr 26, 2019 9:32:08 AM

When fluids undergo a phase change (see Phase Change - Make Mine a Double), it typically has a very significant effect of the flow behavior and energy level of the system.  Some examples of this are: cavitation in a pump, condensing near the exit of a steam turbine, even the everyday phenomenon of the weather is basically a never-ending phase change process of water, and its interaction with air. 

What do Undergraduates, a Chimney, Renewable Energy and an Open Pit Mine Have in Common?

by Francis A. Di Bella, P.E. on Apr 19, 2019 10:14:00 AM

It sounds like an opening to a joke, but I wanted to share some creative thinking sparked during a field trip to a local gas turbine cogeneration plant with some undergraduate students I teach. The students were learning about basic thermodynamics, and visiting a power plant was a good way to give them perspective of what a kW is, and how much hardware and floor space is needed to generate 21,000 of them. I scheduled the trip for when the Gas Turbine system was “down for routine maintenance”, so the students could really crawl in and around the “beast” and be able to hear the explanations of the tour guide. 

Topics: thermodynamics

Simple Stall - Video Blog - Part 2

by Mark R. Anderson on Apr 12, 2019 9:33:58 AM

Our CTO, Mark Anderson, takes a fundamental look at simple stall and its impact on turbochargers stability and range. This is the second video in this 2-part series. Be sure to watch Part 1 first!

Performance Corrections for Compressor Maps

by Mark R. Anderson on Apr 9, 2019 9:56:09 AM

Turbomachinery performance is almost always analyzed and tested with a fixed inflow condition. In other words, the assumption is that the inflow fluid temperature and pressure is defined and unchanging over the map of machine performance. Since varying conditions often exist in practice, the performance maps are sometimes normalized, as shown in the figure below. The pressure ratio of a compressor is plotted versus a corrected mass flow range and rotational speed. 

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