What are Variable Geometry Turbochargers?
The aspect ratio of a turbocharger’s housing is very important for aircraft engine and its boost ability. When aspect ratios are too small, there is little ability to create boost at lower speeds. On the other hand, having too great of a ratio can cause the engine to choke while in higher speeds, leading to drawbacks such as high pumping losses and lower output of power. Variable geometry turbochargers serve as a solution for this problem and are a rapidly developing technology.
Turbochargers are designed to aid engines in their performance while allowing their design to remain reasonably small and compact. As power is created through the combustion of oxygen and jet fuel, having a constant supply of oxygen dense air is critical for optimal functionality. Turbochargers work to increase internal combustion by forcing in and compressing extra air into the combustion chamber.
The variable geometry turbocharger is a type of turbocharger that allows for the control of the aspect ratio of the turbine housing, which enables the ratio to always remain at an optimal level by altering the housing geometry. These types of turbochargers feature vanes in the housing of the turbine that are shaped to be aerodynamic. As the engine speeds up or slows down, the vanes change and create more variability to maintain an optimal aspect ratio.
Variable geometry turbochargers originally were mostly seen with diesel engines due to lower exhaust temperature, though with breakthroughs in material technology, they have now begun branching out to gasoline engines such as in sports cars. Other applications for these turbochargers include those such as commercial, passenger, marine, and rail combustion engines.
