Session: 32-03 Compressor Design Methods

Paper Number: 102827

102827 - Extension of the Multall Open Source Throughflow Code for the Improved Endwall Loss Simulation 

Accurate loss modeling is extremely important for throughflow calculations in order to capture correct streamtube definition as well as the accurate spanwise distribution of flow properties during quasi three-dimensional design of a turbomachinery blade. In this study, the modification of Cf(friction factor)-based loss computation in Multall throughflow code and its difference from classical empirical loss-based throughflow solvers are studied. The original form of the Multall applies constant friction factor on whole wetted surfaces in order to account the losses in throughflow analysis. However, in a typical turbomachinery blade passage regardless of compressor or turbine, the entropy generation near the endwall regions cannot be handled by imposing constant Cf on the wetted surface due to complex endwall flow structure. In order to improve the loss prediction capability of Multall, the friction factor near the endwall regions is modified so that all these complex flow structures can be resolved. In other words, the Cf values are recalculated near the endwall regions so that secondary and tip clearance losses can be represented accurately. Furthermore, the empirical based loss prediction capability is also brought to the Multall via distributed loss model approach. The entropy gradient that is required for calculation of friction force on blade surfaces are calculated from empirical loss models. Then, then calculated friction force is included to solution into the Multall via source term. The both methods are validated with the experimental results of single stage transonic compressor. The modified Cf model shows better agreement with experimental data near the endwalls as compared to results of empirical based model and original form of Multall.

Presenting Author: Mustafa Bilgiç TEI

Presenting Author Biography: The author has been graduated from mechanical engineering departmen of METU in 2013. In the same year, he has started to as an aerdoynamic design engineer in Tusaş Engine Industry (TEI). Currently, he is aerodynamic chief enginner in chief engineering office in TEI. Starting from 2013, he worked on aerodynamic design of high pressure turbine for indigenious turboshaft engine. Also, he developed in-house aerdoynamic design tool for axial flow turbomahinery. He graduated from the master program in mechanical engineering departmen of METU in 2015. In the same year, he started to Ph.D program in the same department. As a Ph.D topic, he has been working on development of design tool for organic Rankine Cycle (ORC) turbines.

Authors:

Mustafa Bilgiç TEI
Özgür Uğraş Baran METU
Mehmet Haluk Aksel METU