Modern Challenges in Aviation Propulsion Systems

Update – February 28, 2023: AxCYCLE is our legacy software and is depreciated by AxSTREAM System Simulation. System Simulation was born out of the union of the legacy AxCYCLE and AxSTREAM NET software packages.

Introduction

Aviation is coming into a new age of carbon free energy, similar to what is being explored with ground transportation. Currently, aviation transportation generates about 2.5% of the global CO2 emission [1]. Several countries have introduced targets to achieve net-zero emissions by 2050 [2].

Many aerospace teams have joined the great engineering challenge to change the future of aviation.  With this, a number of different types of aircraft with different types of propulsion systems have been proposed.

Hybrid Propulsion System

The first step to a carbon-free propulsion system is hybrid technology. This kind of power plant increases efficiency, decreases emission of greenhouse gases and uses a traditional engine to produce electricity and electric motors to drive the fans or propellers [3].

The chemical engines operate at optimal conditions at any mode of a route. On the other hand, the electric motor is able to work in generator mode, using the kinetic energy of the vehicle during deceleration.

Hybrid propulsion energy system
Figure 1 – Hybrid propulsion energy system

The hybrid aircraft is classified by several attributes. Using thrust devices, we will consider the two base types of propellers and fans. Read More

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

Part 1

Update – March 1, 2023: AxSTREAM NET is our legacy software depreciated by AxSTREAM System Simulation. System Simulation was born out of the union of the legacy AxCYCLE and AxSTREAM NET software packages.

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

Modeling and Simulating Bearings/Bearing Leakages

Update – March 1, 2023: AxSTREAM NET is our legacy software depreciated by AxSTREAM System Simulation. System Simulation was born out of the union of the legacy AxCYCLE and AxSTREAM NET software packages.

Bearings are very important machinery components since they dominate machine performance. Almost all machines and mechanisms with a rotating part, from the smallest motor to the largest power plants, from turbomachinery to reciprocating engines, and other industrial equipment our modern society relies upon, could not function without the use of bearings in some form. If one of the bearings fail, not only do the machines stop, but the assembly line also stops, and the resulting costs may be extremely high. For this reason, every bearing manufacturer makes every effort to ensure the highest quality for each bearing and that the end user subjects the bearing to careful use and properly maintains this component.

A bearing can be defined as a machine element which supports another moving machine element (known as a journal). It permits a relative motion between the contact surfaces of the members, while carrying the loads (static and dynamic). Some consideration will show that due to the relative motion between the contact surfaces, a certain amount of power is wasted in overcoming frictional resistance. If the rubbing surfaces are in direct contact, there will be rapid wear. In order to reduce frictional resistance, wear, and in some cases to carry away the heat generated, a layer of fluid (known as lubricant) may be provided. This lubricant is used to separate the journal and bearing, which allows the moving parts to move smoothly and helps to achieve more efficient machine operation. Some of the common bearing types are shown in Figure 1.

Figure 1. Common Types of Bearing Examples. SOURCE: [1]
Figure 1. Common Types of Bearing Examples. SOURCE: [1]
The main purpose of bearings is to prevent direct metal to metal contact between two elements that are in relative motion. This prevents friction, heat generation and ultimately, the wear and tear of parts. It also reduces the energy consumption required for moving parts. Additionally, they also transmit the load of the rotating element to the housing. This load may be axial, radial or a combination of both. Bearings also restrict the freedom of movement of moving parts to a predefined direction. With all these aspects, bearings are clearly important for the operations and the reliability of mechanical products. The right bearing can increase useful life of the machine, and enhance the machine’s overall performance. The wrong bearing can lead to premature failure, increased downtime, and increased wear and fatigue among all components of the machine. 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

Modeling and Analysis of a Submarine’s Diesel Engine Lubrication System

Update – March 1, 2023: AxSTREAM NET is our legacy software depreciated by AxSTREAM System Simulation. System Simulation was born out of the union of the legacy AxCYCLE and AxSTREAM NET software packages.

Even in today’s age of underwater nuclear power, the majority of the world’s submarines still use diesel engines as their main source of mechanical power, as they have done since the turn of the century. A diesel engine must operate at its optimum performance to ensure a long and reliable life of engine components and to achieve peak efficiency. To operate or keep running a diesel engine at its optimum performance, the correct lubrication is required. General motors V16-278A type engine is normally found on fleet type submarines and is shown in Figure 1. This engine has two banks of 8 cylinders, each arranged in a V-design with 40 degree between banks. It is rated at 1600 bhp at 750 rpm and equipped with mechanical or solid type injection and has a uniform valve and port system of scavenging[1].

Figure 1. GM V16-278A, Submarine Diesel Engine. SOURCE: [1]
Figure 1. GM V16-278A, Submarine Diesel Engine. SOURCE: [1]
Lubrication system failure is the most expensive and frequent cause of damage, followed by incorrect maintenance and poor fuel management. Improper lubrication oil management combined with abrasive particle contamination cause the majority of damage. Therefore, an efficient lubrication system is essential to minimize risk of engine damage.

The purpose of an efficient lubrication system in a submarine’s diesel engine is to:

  1. Prevent metal to metal contact between moving parts in the engine;
  2. Aid in engine cooling by removing heat generated due to friction;
  3. Form a seal between the piston rings and the cylinder walls; and
  4. Aid in keeping the inside of the engine free of any debris or impurities which are introduced during engine operation.

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All of these requirements should be met for an efficient lubrication system. To achieve this, the necessary amount of lubricant oil flow rate with appropriate pressure should circulate throughout the entire system, which includes each component such as bearings, gears,  piston cooling, and lubrication. If the required amount of flow rate does not flow or circulate properly to each corner of the system or rotating components, then cavitation will occur due to adverse pressure and excessive heat will be generated due to less mass flow rate. This will lead to major damage of engine components and reduced lifetime.
Read More

Hydrogen Energy: History, Applications, and Future Developments

A Brief History Of The Discovery Of Hydrogen 

The release of combustible gas during the interaction of metals and acids was observed as early as the 16th century. That is, during the formation of chemistry as a science. The famous English scientist Henry Cavendish had studied the substance since 1766, and gave it the name “combustible air”. When burned, this gas produced water. Unfortunately, the scientist’s adherence to the theory of phlogiston (the theory that suggested the existence of a fire-type element in materials) prevented him from coming to the correct conclusions.

Henry Cavendish (1731 – 1810)
Henry Cavendish (1731 – 1810) Source: https://www.butterflyfields.com/henry-cavendish-contributions-in-science/

In 1783 the French chemist and naturalist A. Lavoisier, together with the engineer J. Meunier, and with the help of special gas meters carried out the synthesis of water, and then its analysis by means of decomposition of water vapor with hot iron. Thus, scientists were able to come to the correct conclusions, and dismantle the phlogiston theory. They found that “combustible air” is not only a part of water but can also be obtained from it. In 1787, Lavoisier put forward the assumption that the gas under study is a simple substance and, accordingly, belongs to the number of primary chemical elements. He named it hydrogene (from the Greek words hydor – water + gennao – I give birth), that is, “giving birth to water”.

Antoine-Laurent
Antoine-Laurent
de Lavoisier (1743 – 1794). Source: https://educalingo.com/en/dic-en/lavoisier

A Little About The Properties Of Hydrogen 

In a free state and under normal conditions, hydrogen is a gas, and is colorless, odorless and tasteless. Hydrogen has almost 14.5 times mass less than air. It usually exists in combination with other elements, such as oxygen in water, carbon in methane, and organic compounds. Because hydrogen is chemically extremely active, it is rarely present as an unbound element. 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

Aircraft Life Support Systems Part 2: Water and Waste System

Previous Blog

Update – March 1, 2023: AxSTREAM NET is our legacy software depreciated by AxSTREAM System Simulation. System Simulation was born out of the union of the legacy AxCYCLE and AxSTREAM NET software packages.

INTRODUCTION
In the aircraft industry, several systems are designed to provide safety and comfort for the crew and passengers.

Regarding comfort, the water and waste system is designed to provide water for galleys and lavatories. Fresh water is stored and distributed while a different system deals with wastewater. That system includes a thoughtful engineering method to dispose of the different wastes that could occur during the flight.

OVERVIEW

Water must be supplied to different parts of the plane during flight. This water is kept in a tank in the compartment aft of the bulk cargo compartment. The whole system is made up of a passenger water system that stores, delivers, monitors and controls drinkable (potable) water for the galley units and lavatory sink basins.

In this blog, we are going to focus more specifically on the 737-classic model from Boeing.

Figure 1-Representation of different parts of the water and waste system
Figure 1-Representation of different parts of the water and waste system

The 3 main achievements of the water and waste system are the following:

  • Filling the water tank on land
  • Providing water during the flight
  • Storing toilet waste

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The water and waste system is made up of:

  • Potable water system aims to deliver fresh water to every needed part in the plane (including every component between the water tank and sinks)
  • Water tank pressurization system focuses on the pressurization of the water tank and air dealing with the tank (including air compressor, pressure regulator filter, pressure relief valve)
  • Wastewater system focuses on water related to lavatory and sinks / galleys wastewater (including drain masts)
  • Toilet system includes components related to flushing and toilet water (including waste tank)

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The water tank has a capacity of 34 gallons (about 0.15 m3). The water system in the plane needs to be pressurized for altitude just like the cabin, so it gets pressurized by an air inlet (linked to the pneumatic system). Therefore, the water quantity should not exceed 30 gallons (about 0.13 m3). Read More