Modeling of Combustor-Turbine Vane Interaction Using Stress-Blended Eddy Simulation

Abstract

Modeling the interaction between gas turbine engine modules is complex. The compact nature of modern engines makes it difficult to identify an optimal interface location between components, especially in the hot section. The combustor and high-pressure turbine (HPT) are usually modeled separately with a one-way boundary condition transfer to the turbine inlet. This approach is not ideal for capturing all the intricate flow details that travel between the combustor and the turbine and for tracking hot streak migration that determines turbine durability. Modeling combustor-turbine interaction requires a practical methodology that can be leveraged during the engine design process while ensuring accurate, fast, and robust CFD solutions. The objective of this paper is to assess the effectiveness of joint simulation versus co-simulation in modeling combustor and turbine interaction. Co-simulations are performed by exchanging information between the combustor and the turbine stator at the interface, wherein the combustor is solved using Stress-Blended Eddy Simulation (SBES) while the stator is solved using RANS. The joint combustor-stator simulations are solved using SBES. The benefits of using SBES versus LES are explored. The effect of the combustor-stator interaction on the flow field and hot streak migration is analyzed. The results suggest that the SBES model is more accurate than LES for heat transfer predictions because of the wall treatment and the joint simulation is computationally efficient and less prone to interpolation errors since both hot section components are modeled in a single domain.

Study of Combustor–Turbine Interactions by Performing Coupled and Decoupled Hybrid RANS-LES Simulations under Representative Engine-like Conditions

“…An alternative to SAS and DES is represented by the stressblended eddy simulation (SBES) model, that has become increasingly popular in recent years since it allows modeling of the boundary layers regions using RANS instead of using the more expensive LES, in terms of computational resources required [36]. For example, Verma et al [37] simulated a coupled combustor-turbine configuration by using SBES. The results were then compared to those obtained by using RANS for only the NGV and SBES for only the combustor, noting that the decoupled approach is less efficient than the coupled one because an interactive procedure is necessary in order to converge the co-simulation model.…”

Numerical Study of Combustor-Turbine Interaction by Using Hybrid RANS-LES Approach

“…More recently, the Stress-Blended Eddy Simulation (SBES) model has been used to assess the effectiveness of a combustorturbine integrated simulation versus modeling them separately [36]. Such innovative hybrid approach proposed by Menter [37] represents a further development of hybrid models, like SAS and DES, and it allows to avoid the computationally expensive LES in boundary layers that are modelled by RANS.…”

“…Such innovative hybrid approach proposed by Menter [37] represents a further development of hybrid models, like SAS and DES, and it allows to avoid the computationally expensive LES in boundary layers that are modelled by RANS. In particular, the authors [36] studied first the two components by modeling them separately by a SBES of the combustor and RANS for the NGV by exchanging information between them at the interface. Then they proceeded with an integrated combustor-NGV calculation SBES.…”