This workshop presents an overview of turbocharger function and design and explains the fundamental physical principles that govern turbocharger operation. This background information is used to establish the basis for defining turbocharger performance and measurement of turbocharger performance both on the test stands and in the field.
The design and construction of turbochargers are examined with descriptions of key components including compressor and turbine wheels, bearings, and seals. Turbocharger cooling and lubrication are also included. Fundamental principles of thermodynamics and fluid mechanics are reviewed and used to establish relationships that describe how turbochargers function and provide the means for defining performance. Methods for normalizing and correcting data are presented.
Given the above background, an in-depth review of variables that need to be measured to fully evaluate turbocharger performance is provided. Mechanical variables include vibration measurement, coolant flows and lubricant flows. Thermodynamic performance variables required include airflow, temperatures and pressures. The distinction and relationships between static and stagnation parameters and the correct measurement or determination of both are explained. Sources of errors in these measurements, means to mitigate these errors, and the effect of errors on performance evaluation are examined.