Internal Heat Transfer Predictions using CFD
(2025) MVKM01 20251Department of Energy Sciences
- Abstract
- To enhance gas turbine efficiency, internal components require advanced cooling. This thesis addresses the challenge of predicting thermal performance in complex matrix cooling geometries. The primary goal was to develop a validated computational fluid dynamics methodology and use it to investigate the impact of bypass channels. First, a numerical model was developed and validated against experimental data, showing good accuracy in predicting heat transfer and pressure drop, particularly in incompressible flow regimes. Subsequently, this model was used to analyze matrix cooling configurations with added bypass channels of varying widths. The results demonstrate that while bypass channels decrease overall heat transfer, they drastically... (More)
- To enhance gas turbine efficiency, internal components require advanced cooling. This thesis addresses the challenge of predicting thermal performance in complex matrix cooling geometries. The primary goal was to develop a validated computational fluid dynamics methodology and use it to investigate the impact of bypass channels. First, a numerical model was developed and validated against experimental data, showing good accuracy in predicting heat transfer and pressure drop, particularly in incompressible flow regimes. Subsequently, this model was used to analyze matrix cooling configurations with added bypass channels of varying widths. The results demonstrate that while bypass channels decrease overall heat transfer, they drastically reduce pressure drop. A key finding is that narrow bypass channels, with widths less than the matrix subchannel width, yield an improvement of up to 20% in the overall thermal-hydraulic efficiency, offering an optimized solution for advanced cooling designs. (Less)
- Popular Abstract
- This thesis was conducted at Siemens Energy AB, a major produced of gas turbines. Modern gas turbine development is driven by a constant push for increased efficiency, but making them more efficient means running them hotter—so hot that their metal components are at risk of melting. To solve this, engineers design intricate cooling passages inside the turbine blades, which act like tiny, complex radiators. However, forcing air through these passages requires energy, creating a delicate balancing act. This work explored how to optimize one of these advanced designs, known as matrix cooling, using computer simulations.
A key part of this work was first establishing a reliable simulation methodology. This involved carefully testing and... (More) - This thesis was conducted at Siemens Energy AB, a major produced of gas turbines. Modern gas turbine development is driven by a constant push for increased efficiency, but making them more efficient means running them hotter—so hot that their metal components are at risk of melting. To solve this, engineers design intricate cooling passages inside the turbine blades, which act like tiny, complex radiators. However, forcing air through these passages requires energy, creating a delicate balancing act. This work explored how to optimize one of these advanced designs, known as matrix cooling, using computer simulations.
A key part of this work was first establishing a reliable simulation methodology. This involved carefully testing and comparing different turbulence models to understand which ones most accurately predict the complex, high-speed flow and heat transfer. This comparison created a vital 'rulebook' for engineers, showing which predictive tools are trustworthy under different operating conditions. Once this methodology was established, the core investigation focused on a specific design question: what is the effect of adding small "shortcut" paths, or bypass channels, to the main cooling network?
The results revealed a critical trade-off. Adding bypass channels dramatically reduces the pressure required to pump air through the blade, a significant energy saving for the turbine. However, this comes at the cost of slightly less effective cooling. The most important finding was identifying the trendline: the smaller the bypass channels leads to higher overall system efficiencies, as the energy savings far outweigh the minor reduction in cooling performance. It was also found that beyond a certain size, larger bypass channels begin to harm the overall performance.
In current design cycles, matrix cooling heat transfer is primarily calculated using 1D experimental correlations, often too simple for the complex flows and geometries the designers push for. This research delivers two key contributions. First, it provides a validated and reliable simulation methodology, including a clear comparison of turbulence models, that gives engineers a faster and more accurate tool for analysis. Second, with a clearer understanding of how bypass channels work, companies can now use this methodology to develop the next generation of more efficient and durable gas turbines more effectively. This thesis work contributes to a more sustainable future for both power generation and aviation. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9204227
- author
- Naversten, Edward LU
- supervisor
- organization
- course
- MVKM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- MSc, Computational Fluid Dynamics, Internal Heat Transfer, Gas Turbine Cooling, Matrix Cooling, Thermal Performance
- report number
- ISRN LUTMDN/TMPH-25/5647-SE
- ISSN
- 0282-1990
- language
- English
- id
- 9204227
- date added to LUP
- 2025-06-23 09:44:42
- date last changed
- 2025-06-23 09:44:42
@misc{9204227,
abstract = {{To enhance gas turbine efficiency, internal components require advanced cooling. This thesis addresses the challenge of predicting thermal performance in complex matrix cooling geometries. The primary goal was to develop a validated computational fluid dynamics methodology and use it to investigate the impact of bypass channels. First, a numerical model was developed and validated against experimental data, showing good accuracy in predicting heat transfer and pressure drop, particularly in incompressible flow regimes. Subsequently, this model was used to analyze matrix cooling configurations with added bypass channels of varying widths. The results demonstrate that while bypass channels decrease overall heat transfer, they drastically reduce pressure drop. A key finding is that narrow bypass channels, with widths less than the matrix subchannel width, yield an improvement of up to 20% in the overall thermal-hydraulic efficiency, offering an optimized solution for advanced cooling designs.}},
author = {{Naversten, Edward}},
issn = {{0282-1990}},
language = {{eng}},
note = {{Student Paper}},
title = {{Internal Heat Transfer Predictions using CFD}},
year = {{2025}},
}