Loss models

For meanline modelling, it is common to rely on empirical correlations to estimate the losses within the turbomachinery. These sets of correlations are known as loss models. This section presents the implemented loss models for each turbomachinery configuration.

Axial turbines

Perhaps, the most popular loss model for axial turbines is the one proposed by [Ainley and Mathieson, 1951, Ainley and Mathieson, 1951] and its subsequent refinements by [Dunham and Came, 1970] and [Kacker and Okapuu, 1982]. The Kacker–Okapuu loss model has been further refined to account for off-design performance by [Moustapha et al., 1990]. The model was further improved in subsequent studies, culminating in enhanced loss correlations for profile losses at off-design incidence [Benner et al., 1997] and endwall losses at design incidence [Benner et al., 2004]. Furthermore, the authors introduced a new formulation for the total loss coefficient using the concept of penetration depth of secondary flows, aiming to enhance the prediction of endwall losses based on the underlying flow physics [Benner et al., 2006].

The loss models implemented in the meanline code is further described in each separate section:

• Kacker-Okapuu (1982)
• Benner-Sjolander-Moustapha (2006)
• Moustapha-Kacker-Tremblay (1990)