Imperial College London
Alternate

ProfessorRicardoMartinez-Botas

Faculty of Engineering, Department of Mechanical Engineering

Associate Dean Industry Partnerships,Prof of Turbomachinery
 
 
 
//

Contact

 

+44 (0)20 7594 7241r.botas Website

 
 
//

Location

 

611City and Guilds BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@inproceedings{Liu:2018,
author = {Liu, H and Romagnoli, A and Ismail, MI and Martinez-Botas, R and Rajoo, S and Padzillah, MH},
pages = {291--308},
title = {Multi-injection turbine housing: A novel concept for performance improvement in radial turbines},
year = {2018}
}
Download

RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - Secondary flow injection is a way which allows for the efficiency of a turbomachine to be increased further, after blade design optimizations have already been performed. In this paper, a novel method for improving turbine performance using secondary flow injection through an injection slot over the turbine shroud is investigated. Numerical simulations were conducted on a mixed flow turbocharger turbine to test the effectiveness of secondary flow injection. An optimization using Genetic Algorithm was performed at peak efficiency at 50% turbine design speed to determine the injection set up which gives the highest turbine efficiency. The final optimized point gave an increase in efficiency of 2.6 percentage points compared to the baseline turbine. Flow analysis shows that injection partially blocks the flow passage near the blade tip, forcing turbine passage flow to migrate towards the hub. This apparently weakens the hub suction side separation vortex and reduces entropy generation from the vortex. However, entropy generation near the blade tip is increased, and the tip leakage vortex structure has become a counter-rotating vortex pair. Overall, injection reduces the entropy generation in the turbine by 10.7% at the optimized point. The optimized set of injection parameters was then used across 4 different speed lines to generate the turbine performance maps. The turbine maps show an overall increase in turbine efficiency, but a slight decrease in mass flow parameter and increased back pressure. The turbine maps are then used in an engine simulation to predict engine performance with and without injection. Engine performance at full load and part load conditions are simulated at 4 different engine speeds. The engine simulation results show that injection increases the turbocharger boost pressure. As a result, the brake specific fuel consumption (BSFC) of the engine is reduced throughout the engine speeds tested. The greatest reduction in BSFC is at 1050 rpm, where f
AU  - Liu,H
AU  - Romagnoli,A
AU  - Ismail,MI
AU  - Martinez-Botas,R
AU  - Rajoo,S
AU  - Padzillah,MH
EP  - 308
PY  - 2018///
SP  - 291
TI  - Multi-injection turbine housing: A novel concept for performance improvement in radial turbines
ER  -
Download