A Brief History of the Turbocharger – Part 1

Turbochargers are one of the more common turbomachines out there today! As everyone is making efforts to lower carbon dioxide emissions in automobiles, and the automotive OEMs engage in a “horsepower war”, the turbocharger will likely continue to grow in popularity for both civil and commercial uses.

But how did these machines get so popular? That’s what we’ll be exploring in this blog miniseries! Today’s blog will introduce the concept of the turbocharger, and the beginnings of its development around the turn of the 20th century.

Turbocharging engines and the idea of forced induction on internal combustion engines are as old as the engines themselves. Their intertwined history can be traced back to the 1880’s, when Gottlieb Daimler was tinkering with the idea of forced induction on a “grandfather clock” engine. Daimler was supposedly the first to apply the principles of supercharging an engine in 1900, when he mounted a roots-style supercharger to a 4-stroke engine.

The birth of the turbocharger, however, would come 5 years later, when Swiss engineer Alfred Büchi received a patent for an axial compressor driven by an axial turbine on a common shaft with the piston of the engine. Although this design wasn’t feasible at the time due to a lack of viable materials, the idea was there.

Turbochargers vs Superchargers

What idea was that, exactly? And how did it differ from supercharging?

I think it’s important to quickly go over the basic differences between turbocharging and supercharging. Both offer “forced induction” for piston engines. A naturally aspirated engine simply will draw in atmospheric air as the intake valve opens, and the piston travels down to bottom dead center. A forced induction engine, pushes more air into the cylinder than what the dropping of the piston would pull in, allowing more air to be combusted, and thus generating more power and efficiency. While turbochargers and superchargers are both forced induction , how superchargers and turbochargers go about compressing that air is different. Superchargers are driven by the engine themselves, typically via a belt or gear. This uses some of the engine’s available horsepower, but doing so provides more horsepower back to the engine. The compressors can be either positive displacement configurations (such as a Roots or Twin-Screw), or a  centrifugal supercharger.

supercharger configurations
A very helpful image of the 3 kinds of superchargers, courtesy of MechanicalBooster.com

Turbochargers, as mentioned before, use the air from the exhaust of the engine to drive a turbine, and the work of the turbine is transmitted on a common shaft to a compressor. The most common configuration is a radial turbine driving a centrifugal compressor similar to the one above in the supercharger diagram. However, there are other configurations ,seen in larger examples, such as an axial turbine driving a centrifugal compressor. Read More

Micro Gas Turbines in Trains and Railroad Technology

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Welcome to this latest (and sadly, last) entry in the Micro Gas Turbines in Transportation series! Today, we’ll be having a quick look at micro gas turbines and their larger siblings, specifically the history of how they have been used in railroad locomotion and  what the future holds for micro turbines and railroad technology. We’ll also consider the advantages and disadvantages of using them to drive trains.

Rail transportation has been around in one form or another for longer than you might think. There are examples of wheeled carts running on fixed roads and tracks that prevented any deviation being used since the 6th century BC in ancient Greece.

Up until the late 18th Century, however, railroads were rather limited in what they could be used for, since there was no way of mechanically propelling the vehicles used. Rather, these railroads relied on humans, animals, or gravity to move the carts along the tracks. This changed when in 1784, the great Scottish inventor James Watt created and patented the first steam engine locomotive which was an improvement of a steam engine designed by Thomas Newcomen. Following this invention, engineers in the UK working on different projects such as Richard Trevithick and his development of the first high-pressure steam engine would lead to the first uses of locomotive-hauled railway. His invention would be used in Wales on a short 9 mile run from an iron-works in Penydarren to the Merthyr-Cardiff canal.(2)  On February 21st, 1804, the first trip took place on this railway using only steam propulsion.(2) However it wasn’t until George Stephenson’s creation paved the way for public use of steam engines like those created by James Watt on the rails, and in the coming years rail travel would play an important role not just in the United Kingdom but in the United States as well. This raises the question, where and when did turbines and turbomachinery come into play in rail travel?

George Stephenson's Locomotion 1 –
George Stephenson’s Locomotion 1 – image courtesy of Chris55 / CC BY-SA

Believe it or not, gas turbines in trains were being experimented with long before Frank Whittle and Hans von Ohain were designing them to take to the skies. As far back as 1861, the year that Abraham Lincoln became president of the United States, patents were being filed for a turbine that utilized ambient air mixed with combustion gasses to drive a turbine. As seen in patent 1633, Marc Antoine Francois Mennons created an engine that included all of the components needed in a modern gas turbine engine. It was called a “caloric engine” and it had a compressor (called a ventilator), combustion chamber (using ambient air and burned wood or coke), and a turbine to create work from the combustion gasses as well as a pre-heater (which he called a regenerating apparatus).(3)

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Charles Parsons and His Contribution to Engineering

Welcome to this special edition of the SoftInWay blog! While we at SoftInWay are known for helpful articles about designing various machines, retrofitting, and rotordynamics, we believe it is also important to examine the lives of some of the men and women behind these great machines.

The compound steam turbine is one of the greatest inventions, not just in turbomachinery but around the world. Once it was introduced to the marine industry, the steam turbine exploded in popularity as a means of allowing ships to travel faster and farther than ever before. It would go on to become a critical part in the naval arms race that preceded the First World War. The steam turbine not only revolutionized marine and naval propulsion, it became one of the best ways to generate electricity. After its inception, the steam turbine became one of the best ways to reliably generate power on a large scale, and make electricity the regular utility that it is today. But who invented the modern steam turbine?

Sir Charles Parsons
Image courtesy of Wikimedia

Sir Charles Algernon Parsons, (1854 – 1931), is the inventor of the modern steam turbine. The work he undertook in his life had a massive impact on the world, continuing the legacy of James Watt by bringing steam technology into the modern era. Born on June 13th 1854 into an Anglo-Irish family, Sir Charles Parsons was born into a well-respected family with roots in County Offaly, Ireland. In fact the town now known as Birr was then known as Parsonstown, from the early 1600’s through to 1899. Parsons was the sixth son of the 3rd Earl of Rosse, and had a family lineage that had made great strides in the areas of military, political, and physical science. The family’s castle in Birr, which is still owned by the Parsons family and is the permanent residence of the 7th Earl of Rosse, was a rendezvous for men of science during the childhood of Sir Charles. Suffice it to say, there was no better place for a future-engineer to grow up. He alongside his brothers would receive private tutorship from Sir Robert Ball and Dr Johnstone Stoney, famous Irish astronomer and physicist, respectively. Read More

Engineering Luke Skywalker’s X-34 Landspeeder

Today, landspeeders we look at!

Introduction

Landspeeders belong to the “repulsorlift” transport class, like the podracers we looked at last year, and travel above a world’s surface (up to 2 meters) without contact (very useful on swampy lands like Dagobah). Landspeeders are the successors to the hanno speeder which was mainly used as a racing vehicle with many Tatooine natives still using them to race in the Boona Eve Classic today.

Luke Skywalkers Soro Suub Corporation X-34 landspeeder
Figure 1:  Luke Skywalker’s Soro Suub Corporation X-34 landspeeder from the 1977 film – Note, the Soro Suub Corporation was your main go-to landspeeder designer and manufacturer before and during the reign of the Galactic Empire even though it specialized mostly in mineral processing. Image source

Landspeeders are found in both civilian and military applications but due to intergalactic ITAR regulations we will only cover the civil aspect here with a focus on the most famous of them all. If you want to know more about our experience working with military, defense and governmental organizations (whether you area part of the Empire, Rebels, Resistance or Separatists) feel free to contact us.

The Famous X-34

Luke Skywalker’s X-34, with its 6 selectable hover heights, features an engine consisting of 3 air-cooled thrust gas turbines able to reach a top speed of about 155 mph. The side engines are also used for steering although it is not obvious whether this steering is achieved by varying their thrust to be asymmetric or through vectoring of their exhaust. With the X-34 total length being 3.4 meters it helps us estimate the overall dimensions of its engines which are, each, roughly 80 cm long by 30 cm wide. Read More

Micro Turbines in Maritime Transportation

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Hello! Or should I say, welcome aboard! In this edition of micro gas turbines in transportation, we’re going to be looking at micro gas turbines in the marine world. Marine transportation presents its own set of unique challenges not seen in other forms of transportation; although some of the common challenges and hurdles will be seen here too. If you haven’t read the other entries, or the introduction, I highly recommend you do so here.

Out of all the different vehicles and forms of transportation that will be covered in this series, the boat as we know it is one of the oldest ways of getting about. From rowing to sailing to paddle wheels and engines, the boat has a long history of carrying every kind of good and being imaginable. Much like the topic of turbines, marine transportation can take up oceans of information; in fact you might say that it’s a whale of a topic.

Whale Whale Whale
Whale, here we are with another pun. I hope it brightens your day at least! Image courtesy of The Georgia Aquarium

This blog will specifically cover a brief history of motorized marine transportation, where/how micro turbines can be used, and the inherent advantages and disadvantages. Let’s get started!

A Brief History of Engines in Marine Transportation

Steamboats became popular in the 19th Century when the Industrial Revolution was in its early stages. Steam engines like the ones designed by James Watt were used to propel everything from small riverboats like the ones that went up and down the Missouri river, to oceangoing steamships. The engines typically drove a propeller or “screw” or a large paddle wheel like what is commonly seen on a watermill. Different steam engines in different configurations dominated marine transportation throughout the 19th century, and by the turn of the 20th century, large expansion engines began to be utilized for oceangoing ships like the Olympic-class ocean liners as well as warships. Read More

Turbomachinery System and Component Training: Something for Everyone!

Mechanical engineering is an ever-changing field, and we want to be there to help engineers stay ahead of the curve, even while they are flattening it. In that spirit, we wanted to share with you our different training options that are available now. Whether you are looking to brush up on the fundamentals, or evaluate a software platform, this is a great time to train and explore the latest and greatest in turbomachinery engineering.

Without further ado, let’s get into it!

Private Corporate Trainings Online

First and foremost, the best most comprehensive training you can get from SoftInWay is a private session with one of SoftInWay’s lead engineers and your team. Why is this the best training option? A couple of reasons:

  • Courses are entirely customizable: The scope of these private training courses is tailored to your specific needs. Are you looking to learn the fundamentals? Or perhaps you want to expand your team’s R&D capabilities when it comes to turbomachinery, rotor dynamics, and 1D thermal systems? Whatever the application, we’ll work with you to develop a course curriculum which brings the most value to you and your team.
  • One-on-one consultation with our expert engineers on individual projects and challenges. Our engineering expertise ranges from flowpath design on a turbomachine, to rotor dynamics, as well as secondary flows/multiphase flows, and other all-encompassing projects such as liquid rocket engine design.
  • ll registrants get a 1-month license of the relevant AxSTREAM modules. During the class, users will be familiarized with the ins and outs of AxSTREAM, and be able to make use of AxSTREAM’s capabilities for 1 month afterwards.

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The class can be as long or as short as you need and scheduled around you and your team. Read More

An Introduction to Shock Waves

When you think of shock waves, I would wager that you picture a supersonic jet zooming past overhead. Or maybe you have experienced the famous (or infamous) “sonic boom” that accompanies shock waves attached to airplane engines. The engineering challenges associated with the often-troublesome behavior of shock waves is present in all scales, from carefully designing the bodywork of the aforementioned fighter jets, to the equally intricate details of flow passages and blade design in turbomachinery. The first step in taking into account the effect of shock waves is to understand what they are. In this post we will be reviewing a short introduction into what shock waves are and a few applications where they might be relevant.

Figure 1: Schlieren image showing the shock waves of a supersonic jet
Figure 1: Schlieren image showing the shock waves of a supersonic jet. Source

What are shock waves?

Shockwaves are non-isentropic pressure perturbations of finite amplitude and from the second law of thermodynamics we can say that shockwaves only form when the Mach number of the flow is larger than 1. We can distinguish between normal shocks and oblique shocks. In normal shocks, total temperature is constant across the shock, total pressure decreases and static temperature and pressure both increase. Across oblique shocks, flow direction changes in addition to pressure rise and velocity decrease. Read More

Cooling Methods in Turbine Blades

Turbine components are placed right after the combustor and are therefore, subject to the highest temperatures in an engine. The turbine blades are directly in the line of fire (so to speak) of these incredibly high temperatures. Higher temperatures yield higher cycle efficiencies, meaning that the limit on efficiency for a cycle is determined by turbine materials. The current state of the art materials can only give so much heat resistance capacity, which makes blade cooling essential. In this post we’ll be taking a look at the various cooling methods that exist for turbine blades, and the tools to design them.

Figure 1: High pressure turbine guide vane with cooling holes
Figure 1: High pressure turbine guide vane with cooling holes. Source

How important is cooling to the efficiency of gas turbine engines?

In a word, very.  Let’s look at an example to better explain.  Our fictitious engine without cooling has an overall pressure ratio of 40 where the maximum allowable turbine entry temperature (TET) is at 1498 K, yielding a thermal efficiency of 33%. When compared to a turbine with cooling, TET can be increased to 1850 K, yielding a thermal efficiency of 38%. This is an 8% increase in efficiency via the addition of cooling. In order to achieve good thermal efficiency in our cycles, turbine components must be cooled!

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Micro Gas Turbines in the Aerospace Industry

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Hello and welcome to the next entry in our series on micro gas turbines! If you’re new to this series, be sure to check out our earlier blog where we: introduce the concept of the micro gas turbine; look into the history of it; and discuss some advantages and disadvantages that come with this technology.

This time, we’ll be looking at micro gas turbines in the Aviation industry (if you couldn’t guess by the title). Believe it or not, the concept and configuration of a micro gas turbine has been present in this industry for decades. We’ll get into that in a minute.

Gas turbines are certainly no stranger to the aviation industry. As a matter of fact, when many of us hear the term “gas turbine” we immediately jump to the image of a jet engine powering a massive airliner carrying us to our next adventure.

Engine of airplane
The Mighty Turbofan Engine; Brought about with thanks to Sir Frank Whittle!

Yes, these mighty turbines are indeed a staple in the aerospace industry.  But did you know that micro gas turbines are also making a rise in this industry?

Although micro gas turbines first made an appearance as an alternative to traditional piston engines in the automotive industry, they have actually been present in the aviation industry for some time.

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The Importance of Accurately Modeling a Rotor-Bearing System

Hello and welcome to the latest revolution in our series on rotor dynamics and bearing analysis. This month, we’ll be looking at what steps need to be taken to accurately model a rotor train, from the components on the rotors themselves to the bearings and structural components that support the entire machine. If you haven’t had a look at the other entries in this series, you can find them here: Series Preface

  1. What is Rotor Dynamics? And Where is it Found?
  2. Why is Rotor Dynamics so Important?
  3. What API Standards Govern Rotor Dynamics Analysis?
  4. Basic Definitions and Fundamental Concepts of Rotating Equipment Vibrations
  5. The Purposes and Objectives of Rotor Dynamics Analyses

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So what is the importance of accurately modeling a rotor-bearing system? Well we already know that an inaccurate analysis can have catastrophic consequences… If you want to know more about why, I also suggest looking at entry 2, titled “Why is Rotor Dynamics so Important?”.

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