Surface roughness quantification for turbochargers

MHI in Alemere, NL, offers several MSc topics in the field of turbocharger design, performance modeling and equipment testing. Interested students who would like to know more about the possibilities to do their MSc thesis together with MHI Alemere are welcome to contact:

Ir. Adeel Javed
Performance Engineer
Tel.:+31 36 538 8045

Dr. Rene Pecnik
Delft University of Technology
Process & Energy Dept., Energy Technology
Tel.: +31 15 2789153


Involved People:

Facilities used:

In a turbocharger compressor, the volute simply transfers air from the diffuser to the pipe downstream to the engine inlet manifold. Similarly the turbine volute collects the flow from the engine exhaust manifold and guides it to the turbine. Despite the simplicity of the purpose, the volute can be a complex component to design and analyze. Volute is basically divided into three parts; the scroll, tongue or cutwater, and the delivery pipe. Due to complexity of the shape, volutes are manufactured using sand casting. The process is effective and cheap; however, surface roughness is inherently high in the fabricated parts. For turbomachinery, skin friction is a critical parameter influencing the overall performance and efficiency. Volute wall roughness, therefore, can be a significant contributor to loss in turbomachine efficiency. During manufacturing, coating is applied over the cores which form the cavities within the casting in order to reduce the surface roughness, incurring an additional manufacturing cost. In case of volutes, it would be valuable to know the overall impact of surface roughness on turbomachine performance and the most sensitive locations. Manufacturing cost can thus be reduced if only the critical locations are coated instead of the complete cavity.

The pdf file can be found here.