Session: 34-05 Physics-based and machine learning models

Paper Number: 153707

Analytical Model for Leakage Prediction in an Axial Labyrinth Seal 

Compact size and efficiency of a radial turbomachine makes it a preferred choice for sub-megawatt (MW) scale supercritical CO₂ power plants.  At sub-megawatt power thresholds, mitigation of parasitic losses stemming from working fluid leakages at the rear facet of turbomachinery emerges as a critical issue. Consequently, it is essential to precisely quantify the leakage flow rates during the preliminary design of turbomachinery. The present paper introduces a novel, one-dimensional leakage prediction model targeted at a see-through sCO2 labyrinth seal configuration. The proposed model is underpinned by a theoretical framework and corroborated through empirical findings from literature and computational simulations. Parametric examinations of the see-through sCO₂ labyrinth seal, spanning diverse geometrical configurations and operational conditions are numerically investigated. A dimensionless leakage function is posited to outline the operational characteristics typical of a sCO₂ labyrinth seal. Validity assessments are extensively conducted, encompassing trapezoidal and slant tooth profiles of a transparent labyrinth seal, to affirm the universality and robustness of the analytical model. Notably, the model demonstrates a high degree of accuracy in predicting leakage rates across all examined conditions, with an error margin of within 10%. This analytical tool exhibits expedited computation capabilities while adeptly ascertaining leakage rates, static pressure distributions within seal cavities, and temperature drops at individual seal teeth. The utility of this leakage prediction model not only extends to preliminary labyrinth seal designs but also facilitates rotor dynamic analysis to be comprehensively investigated.

Presenting Author: Saurabh Lanjewar Indian Institute of Science Bengaluru, Karnataka

Presenting Author Biography: The presenting author is Saurabh Deorao Lanjewar. He is from Maharashtra, India. He finished
his Bachelor's in the Mechanical Department at Nagpur University, Maharashtra, in 2019. He
has done his Master's in Heat Power Engineering at VNIT, Nagpur, in 2021. Presently, he is
pursuing his PhD in the Mechanical Department at IISc, Bengaluru, India. In IISc, he works
with Prof. Pramod Kumar in the sCO2 Lab.

Authors:

Saurabh Lanjewar Indian Institute of Science Bengaluru, Karnataka
Pramod Kumar Indian Institute of Science
Pramod Chandra Gopi Triveni Turbines Limited