A review of the literature on mixed-flow turbomachinery reveals a surprising variation in the ways engineers use the term ‘mixed-flow turbomachine’. In particular, two main conceptions of the term stand out. On the first conception, ‘mixed-flow’ refers to the union of axial and radial flow directions into one diagonal flow, resulting in what some call diagonal turbomachines. In the second conception, ‘mixed-flow’ refers to the combination of distinct elements where the flow is axial in some and radial in others. This kind of machine is sometimes called an axial-radial combined turbomachine. Di ..read more

The fields of energy conversion and propulsion systems stand at the forefront of technological innovation, driving advancements in transportation, aerospace, and sustainable energy solutions. In the quest for optimized performance and efficiency, researchers are increasingly turning to holistic modeling approaches that bridge the gap between 0D and 3D simulations. The integration of simulation levels offers a more comprehensive understanding of complex systems by combining simplified, yet accurate, 0D models with highly detailed 3D representations. In this exploration of holistic modeling, we ..read more

The earliest device for extracting rotary mechanical energy from a flowing gas stream was the windmill. It was followed by the smokejack, first sketched by Leonardo da Vinci and subsequently described in detail by John Wilkins, an English clergyman, in 1648. This device consisted of a number of horizontal sails that were mounted on a vertical shaft and driven by the hot air rising from a chimney. With the aid of a simple gearing system, the smokejack was used to turn a roasting spit. Various impulse and reaction air-turbine drives were developed during the 19th century, making use of air compr ..read more

From the electricity that charges our phones to the jet engines that propel airplanes across the sky, turbines can be found powering our modern world in various forms and configurations.  These mighty machines are the silent heroes of our energy infrastructure, found in everything from locomotives and power plants to industrial machinery and rocket engines. But what distinguishes one turbine from another? How do engineers decide on the design and configuration of these mechanical marvels? This intricate task requires an understanding of turbomachinery design, including axial and radial co ..read more

Authors note:  While I have the utmost respect for die-hard Star Wars fans, I must confess that growing up, Episode I was my favorite. Perhaps it was the allure of Darth Maul’s dual lightsaber, the adrenaline-pumping Podracing on Tatooine, or Natalie Portman (no elaboration needed) that captivated my young mind. Although May 4th has already passed this year, my love of Episode I combined with my upcoming presentation at JANNAF had me thinking that perhaps it’s time to revisit the engineering behind Podracers. In a previous blog post, we explored the possibilities of redesigning Anakin’s P ..read more

– Look! Up in the sky! – It’s a Bird! – It’s a Plane! – No! It’s… Oh it’s drones again… If you hear a bzzzz annoying you, do not rush to look for the unfortunate fly to finish it off. Perhaps it is also troubled by the sound that this flying aluminium box makes. Drones come in many forms, some harmless and some dangerous. Let’s look at which is which and discuss some of their unique features. Drones are flying robots, including unmanned aerial vehicles (UAVs) that can fly thousands of kilometers, as well as small drones designed for confined spaces. Aerial vehicles that do not carry a human op ..read more

Introduction Throughout history, humans have had an insatiable desire to understand the world around them, including the stars. The science of rocketry has been developing for centuries, even predating our current era. Today’s rockets are the result of numerous experiments and the combination of many different areas of engineering. Few things can withstand the extreme conditions that rockets must endure, including the intense loads during launch and drastic temperature changes caused by cryogenic components and combustion chambers. Successful launches depend heavily on well-informed design dec ..read more

Choosing the number of stages during the development of axial turbines is one of the most controversial design tasks because it has many options to consider. This task does not have an exact solution, since it depends on the total turbine work, circumferential velocity and is determined by a combination of gas-dynamic, strength, construction, and technological factors. This blog will discuss some of the considerations for stage number selection of an axial turbine. Using Stage Loading vs Parson’s Parameter Designing turbines requires the use of complex parameters to simultaneously consider the ..read more

Theoretical overview In pumps, compressors, gas turbines, and powertrains with rotating parts, there are typically cavities between the spinning rotor and the fixed stator elements. The flow’s behavior at those cavities can significantly affect a machine’s temperatures, structural loads, vibrations, and overall efficiency. Similar radial cavities, where the flow is restricted between a rotating part and a non-rotating wall, are ubiquitous in the secondary flow channels of gas turbine engines (Figure 1). Figure 1 – Example of secondary flows in a gas turbine engine [1]Careful planning of second ..read more

A pipe diffuser is a special type of radial vane diffuser and is widely used in centrifugal compressors of gas turbine engines. Employing pipe diffusers can lead to increased efficiency in centrifugal compressors by an average of 2-4% compared to other vaned diffusers. The efficiency gains are especially prominent at high-pressure ratios (over 5.0), toward which we are seeing a growing trend in gas turbine engines. Figure 1 (left): Single flow path of pipe diffuser & Figure 2 (right): Pipe diffuser assembly Figure Source: Stanislaw Antas, Exhaust System for Radial and Axial-Centrifugal Com ..read more