Hans von Ohain – The Other Father of Jet Engines and the Gas Turbine

The question of who invented the jet engine is often met with two different answers, and neither is really wrong. In fact, we posed this question on our LinkedIn page, and got the same mixed results seen elsewhere.  Both Sir Frank Whittle and Hans von Ohain were responsible for inventing the turbojet engine at the same time. While Dr. von Ohain knew of Sir Frank’s work, he did not draw information from, while Sir Frank was unaware that anyone else was designing a turbojet engine.  While we’ve covered Sir Frank Whittle before, today we’ll be looking at the life of Hans von Ohain, his invention of the turbojet, and his contributions to turbomachinery engineering.

Dr. Hans von Ohain
Dr. Hans von Ohain

Dr. Hans Joachim Pabst von Ohain was born on December 14, 1911 in Dessau, Germany. He went to school at the University of Göttingen where he received his PhD in Physics and Aerodynamics in 1935. During his studies and following his graduation, he was captivated by  aviation and airplane propulsion, with a specific interest in developing an aircraft that did not rely on a piston-driven propeller. According to the National Aviation Hall of Fame, he “conceived the idea for jet propulsion in 1933 when he realized that the great noise and vibrations of the propeller piston engines seemed to destroy the smoothness and steadiness of flying”. (1) Read More

2020 – The Most Challenging Year in Recent Memory Comes to a Close Pt. 2

Part 1

Turbomachinery, Humanized

The SoftInWay turbomachinery blog is known for its technical breakdowns and explanations of mechanical engineering theory and practices, as well as introductions to things like rotor dynamics. This year however, the marketing team also wanted to cover some of the individuals behind the advances in turbomachinery and engineering by looking at figures like Sir Frank Whittle and Sir Charles Parsons among others.

We looked at the big picture, and why the developments of the steam and gas turbines were so crucial to mankind. In addition to the revolutionary changes in global transportation brought about by jet engines and steam turbines, we also examined the turbocharger, which has become a game changer in the automotive industry as automakers are locked in a race to improve engine performance and fuel economy while reducing greenhouse gas emissions. After all, why learn the theories of mechanical engineering if not to make advances in science, technology, and society overall? Read More

2020 – The Most Challenging Year in Recent Memory Comes to a Close Pt. 1

Part 2

We’ve done it! We have reached the finish-line for 2020, and by golly did it not come soon enough. Here at SoftInWay, the trials and tribulations brought on by the events of 2020 were felt, but thanks to the support of our partners, friends and customers, we were able to close out the year strong. So what did SoftInWay do this year?

Siemens Partnership

Siemens Partnership

Right at the beginning of 2020, SoftInWay, Inc. officially entered a new partnership with Siemens Digital Industries. As SoftInWay has reigned as the turbomachinery master, we realize that turbomachinery component and system design is often part of a much greater system. As deadlines on projects become tighter, and project budgets decrease in the face of rising expenses, it has become more important than ever to have a streamlined workflow and toolset. Enter the SoftInWay/Siemens partnership. Thanks to this new enterprise, SoftInWay offers joint software solutions to mechanical engineering and turbomachinery companies. Industry standard tools like STAR-CCM+, Simcenter 3D, and NX CAD are now offered alongside the AxSTREAM platform. These gold-standard tools cover everything from component preliminary design to advanced heat transfer analysis, finite-element analysis, and CFD analysis, with results generated in a matter of hours. Read More

Notable Military Jet Engines

As a special tribute this Veterans Day, we decided to have a look at some of the most notable engines that have been used to propel military vehicles throughout history.

PW F135

Kicking off our list is the Pratt & Whitney 135 turbofan engine. The pride and joy of Pratt & Whitney’s military engine lineup, the 135 powers the US Military’s F35 Lightning II. Presently, two variants of the F135 are used in several different variants of the F35, although it should be noted that the F135 was developed specifically for the F35. The 3 engine variants are known as the F135-PW-100, the F135-PW-600, and the F135-PW-400, each for a different application of the F35. The 100 variant is used in the conventional take off and landing F35A, the 600 is used in the F135B for short take off and vertical landing F35B, and the 400 uses salt corrosion-resistant materials for the Naval variant F35C.

A Lockheed Martin F35A in fight, and an F35C taking off from the USS Abraham Lincoln

The F135 is capable of 28,000 lbf of thrust with the afterburner capability pushing thrust all the way to a whopping 43,000 lbf of thrust, making the Lightning II a supersonic STOVL aircraft suited to a wide variety of applications, as seen in the above illustrations. At the heart of the Pratt F135 are 3 fan stages, 6 compressor stages, and 3 turbine stages. In the STOVL variant, the F135-600 uses the same core components, but is also coupled to a drive shaft which connects the engine to the lift fans which were originally developed by Rolls-Royce, and give the Lightning the ability to hover, perform short distance takeoffs, and vertical landings.

A Royal Air Force RAF F35B Lightning II performing a vertical landing on a Royal Navy carrier.
A Royal Air Force RAF F35B Lightning II performing a vertical landing on a Royal Navy carrier.

The F35 by Pratt & Whitney and in turn the F35 Lightning II by Lockheed Martin represent the cutting edge in military aviation, and are the centerpieces of Pratt and Lockheed respectively. The Lightning variants and this line of turbofan engines will be in service with several branches of the US military and its allies around the world for the foreseeable future, with more iterations of the F135 to come. Read More

The Top 5 Coolest Turbomachinery Inventions (According to Us!)

As the leading authority on turbomachinery design, redesign, analysis, and optimization, we work with a wide range of machines from small water pumps and blowers to massive steam turbines, jet engines, and liquid rocket engines. While all of these machines have a certain “cool factor” to them since, after all, we’ve proven they make the world go round; some machines take coolness to the next level. Today, we’re taking a look at 5 of the coolest specific turbomachinery inventions, according to us.

Number 5 – The Arabelle Turbines

Starting with number 5, we have a pair of steam turbines, each known as “Arabelle”. You may be asking yourself “So what, steam turbines are everywhere.” You would be right, but these two have a bit of a size advantage. In fact, they’re the largest steam turbines in the world.

Designed and built by General Electric in France, these turbines are, according to GE, “longer than an Airbus 380 and taller than the average man. A pair of them, each capable of producing 1770 megawatts, is now set to cross the English Channel to provide energy for generations” (1).

They’ll be installed in a new nuclear power plant known as Hinkley Point C in Somerset. Their 1.7 gigawatt output will be enough to power 6 million homes, which is 7% of the UK’s power consumption. (1) The output and sheer size of the turbines aren’t the only large number either, the project costs nearly 24 billion US dollars.

A CAD model of the Arabelle steam turbines, image courtesy of General Electric.
A CAD model of the Arabelle steam turbines, image courtesy of General Electric.

The sheer size and performance figures have earned GE a place on our list of top 5 cool turbomachines!

Number 4 – The Garrett 3571VA Variable Geometry Turbocharger

This is one only gearheads and diesel-fans may recognize, but even then, it’s an obscure one. This Garrett turbocharger was a game changer for diesel engines used in light and medium duty trucks, specifically the Navistar International VT365, also known as the Ford 6.0 Liter Powerstroke engine. Read More

Turbomachinery in Racing

While Formula racing is well known for its use of standardized turbocharged V6 engines in all races, they’re certainly not the only races where turbocharged engines are used; and in some cases, the vehicle isn’t even a car! Today’s blog is going to look at turbomachinery in racing, starting with the origin of their usage, and looking at some of the different applications where these machines are found.

As we covered in recent blog, turbocharging has been around since the turn of the 20th century, however its applications was limited for a time to heavy-duty marine applications; high-end cars and trucking; and military aviation. By the 1950’s that had changed thanks to Cummins’ entry in the Indy 500, with their advanced turbodiesel engine raising eyebrows until it catastrophically failed. The point was made though, as Indy banned turbodiesels from the races going forward.  Current IndyCar engine specs call for a 2.2 liter V6 engine that is twin-turbocharged with a fixed boost level. These engines can crank out an astonishing 700 horsepower at full chat, which is around 12,000 RPM. If you’re curious about just how Honda is getting this supercar levels of horsepower out of such an engine, I definitely recommend having a look at the magnificent explanation done by Jason Fenske from Engineering Explained.

On the left #28, the Cummins Diesel special which had the famed turbodiesel engine, and on the right, the 2.2L Honda IndyCar engine. Images courtesy of Truck Trend and Engineering Explained respectively.

We’ll circle back to turbocharged road racing in a moment, but let’s talk about jet engines and the H1, first. Started in 1946, H1 Unlimited is a racing league where teams compete using hydroplanes (not to be confused with the extremely dangerous condition that occurs on wet roads). These hydroplanes rely on lift as opposed to their buoyancy to maintain high speeds and maneuverability. After World War II, the surplus of aircraft engines like the famed Rolls-Royce Merlin V12, discussed in an earlier blog, found their way into these high speed watercraft.

The Lycoming T55 turboshaft engine, powering everything from Chinooks, to race boats. Left image courtesy of Mr. Z-man

In modern times however, H1 Unlimited has now standardized the engines used in competing hydroplanes, and all craft must now use the Lycoming T55 turboshaft engine, which was originally used in the famed Boeing CH47 Chinook helicopter.

Read More

The History of Turbochargers, Part 3

Hello! Welcome back to this third and final installment in our “History of the Turbocharger” Series. If you haven’t already, you can read the previous installments by clicking the links below:

Now, let’s see how the turbocharger went from an ace-in-the-hole for aircraft engines during World War II, to the go-to way to crank out horsepower in small engines.

Up until World War II, turbochargers were not a common sight in cars, and certainly not the most popular option for adding forced induction to an engine. Even following the war, some of the most notable post-war aircraft relied on piston engines as opposed to the modern turbojet engine, did not use turbochargers. Most R&D efforts for military aircraft propulsion was moving away from piston engines, and where piston engines were being used, they didn’t have turbos.

Take, for example, the Corvair B36. This behemoth of an airplane was adopted by the US Air Force for a short period of time after the war, but before the much more famous B52 Stratofortress was adopted. This gargantuan plane made use of a Pratt and Whitney radial engine similar to (although much larger than) the engines used in other US warplanes during World War II. Much like the other engines used by warplanes, these engines were typically not turbocharged, instead used geared superchargers to force more air into the 6(!) propeller engines.

A Corvair B36 Peacemaker, which dwarfed the already big B29 Superfortress. By the time the Peacemaker Flew, piston engines were already being considered obsolete for most military and aviation applications.

From the get-go, this engine was quite dated, as the piston engines were maintenance heavy, and the unusual engine and propeller configuration gave the plane reliability issues. Additionally, the Peacemaker was retrofitted with 4 jet engines for use in takeoff as well as speed over a target to reduce the likelihood of being struck by enemy fire. It wasn’t long however, before the turbojet-powered B52 we all know and love was adopted. The B36 was more or less forgotten as a massive placeholder for the US Air Force for a short time following World War II. Read More

The History of Turbochargers, Part 2

Hello! And welcome back for part 2 of our series on “A Brief History of the Turbocharger”. To read part 1, which compares superchargers and turbochargers, and explains the early history of turbochargers and forced induction from the turn of the century through to World War 1, click here. Having covered all of that, let’s pick up from where we left off!

Following World War 1, and the work of Dr. Sanford Alexander Moss, Alfred Büchi, who had created the first true turbocharger, had continued innovating following the failure of his first design. By 1925, he had a working turbocharger design that consistently and reliably worked (1).

Following this breakthrough, the turbocharger saw its first commercial application on ten-cylinder diesel engines. Since diesel engines are typically built to withstand the high-pressures required by their operating conditions, the pressures generated by using forced induction are easily accommodated. As a result of adding the turbochargers, the engines upped their horsepower ratings from 1750HP, all the way to a whopping 2,500HP. (1)

The Hansestadt Danzig, one of the German ships fitted with the 10 cylinder turbodiesel engine described above
The Hansestadt Danzig, one of the German ships fitted with the 10 cylinder turbodiesel engine described above. (shipspotting.com)

For Büchi, this was a great achievement, as it marked the first commercial application of a machine that he had first begun working with more than 20 years prior. For the turbocharger, however, this was just the beginning. Read More

Introduction to Performing Torsional Rotor Dynamics Analysis

Previous Blog 

Hello and welcome to the last part of our series on Rotor Dynamics! In today’s blog we’ll be concluding with torsional analysis, and the steps needed to perform this type of analysis. 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
  6. The Importance of Accurately Modeling a Rotor-Bearing System­
  7. Modeling Bearings and Support Structures in a Rotor Bearing System
  8. Introduction to Performing Lateral Rotor Dynamics Analysis


In an earlier blog, we covered the basic definitions of lateral and torsional analysis. Lateral analysis is concerned with the bending behavior of a rotor train. Torque is a measurement of force that causes an object to rotate on an axis such as when a component needs to be “torqued to spec” in a car’s engine, for example. Torsional analysis, meanwhile, looks at the twisting behavior of the rotor train.

In the context of rotor dynamics, torsional vibrations refer to the oscillatory torsional deformations encountered by the shafts in the rotor train.

Pictured - A shaft undergoing torsional vibration
Pictured: A shaft undergoing torsional vibration.

If these torsional vibrations and excitations are left undamped and aren’t analyzed properly, breakages and catastrophic failures can occur similar to undamped lateral excitations. For more on that, you can read up on the importance of rotor dynamics analysis here.

Read More

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