International Journal of Turbomachinery, Propulsion and Power

18 pages, 3038 KB

Open AccessArticle

Experimental and Numerical Investigation of Heat Transfer of a Side Space of a Steam Turbine Casing at Full and Partial Load

by Bernhard V. Weigel, Oliver Brunn, Thomas Polklas, Stefan Odenbach and Wieland Uffrecht

Int. J. Turbomach. Propuls. Power 2026, 11(1), 3; https://doi.org/10.3390/ijtpp11010003 - 29 Dec 2025

Abstract

There is a significant demand for flexibility in steam turbines, including rapid cold starts and load changes, as well as operation at low partial loads. Both industrial plants and systems for electricity and heat generation are impacted. These new operating modes result in complex, asymmetric temperature fields and additional thermally induced stresses. These lead to casing deformations, which affect blade tip gap and casing flange sealing integrity. The exact progression of heat flux and heat transfer coefficients within the cavities of steam turbines remains unclear. The current methods used in the calculation departments rely on simplified, averaged estimates, despite the presence of complex flow phenomena. These include swirling inflows, temperature gradients, impinging jets, unsteady turbulence, and vortex formation. This paper presents a novel sensor and its thermal measurements taken on a full-scale steam turbine test rig. Numerical calculations were performed concurrently. The results were validated by measurements. Additionally, the distribution of the heat transfer coefficient along the cavity was analysed. The rule of L’Hôpital was applied at specific locations. A method for handling axial variation in the heat transfer coefficient is also proposed. Measurements were taken under real-life conditions with a full-scale test rig at MAN Energy Solutions SE, Oberhausen, with steam parameters of 400 °C and 30 bar. The results at various operating points are presented. Full article

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21 pages, 5453 KB

Open AccessFeature PaperArticle

Performance and Emission Analysis of Aircraft Engines Under Realistic Conditions

by Daniel Lieder, Maximilian Bień, Erik Seume, Sebastian Lück, Federica Ferraro, Jens Friedrichs and Jan Goeing

Int. J. Turbomach. Propuls. Power 2026, 11(1), 2; https://doi.org/10.3390/ijtpp11010002 (registering DOI) - 26 Dec 2025

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Abstract

The impact of the aviation sector on the Earth’s atmosphere and climate is not limited to the effects of CO₂ emissions generated by the combustion of hydrocarbon-based fuel in an aircraft engine. It is complemented by other combustion products and non-CO₂ emissions, such as CO, NO_x, unburnt hydrocarbons (UHCs), and soot, as well as the formation of condensation trails (contrails) as a result of emitted H₂O and condensation nuclei. To evaluate the overall atmospheric impact of an aircraft mission, it is necessary to model the aero engine and the combustion chamber in context with the atmospheric conditions over the course of the flight trajectory. Following that rationale, this paper presents the novel multidisciplinary ‘Modeling and System analysis of Aero Engines’ (MSAE) platform, aiming to evaluate the emission products over the flight trajectory with realistic atmospheric and operative boundary conditions. MSAE comprises an ambient condition model, an aircraft operating model, an aero engine performance model, and a combustion chamber model. The functionality of the individual models as well as their interconnections are demonstrated using the example of an Airbus A320 powered by an International Aero Engines V2500-A1 turbofan engine. Non-CO₂ emissions, including CO, NO_x, UHC, and soot emission indices, can be predicted at a selected operating point. Furthermore, an evaluation of contrail formation for both annually averaged and intraday ambient conditions is conducted, showing the benefit of considering ambient conditions in a finer temporal resolution. The results show the functionality of the presented MSAE platform and the necessity of performance and emission analysis under realistic conditions. Full article

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21 pages, 12257 KB

Open AccessArticle

The Characterization of the Installation Effects on the Flow and Sound Field of Automotive Cooling Modules

by Tayyab Akhtar, Safouane Tebib, Stéphane Moreau and Manuel Henner

Int. J. Turbomach. Propuls. Power 2026, 11(1), 1; https://doi.org/10.3390/ijtpp11010001 - 19 Dec 2025

Viewed by 130

Abstract

This study investigates the aerodynamic and aeroacoustics behavior of automotive cooling modules in both conventional internal combustion engine (ICE) vehicles and electric vehicles (EVs), with a particular focus on installation effects. Numerical simulations based on the Lattice Boltzmann Method (LBM) are conducted to analyze noise generation mechanisms and flow characteristics across four configurations. The study highlights the challenges of adapting classical cooling module components to EV setups, emphasizing the influence of heat exchanger (HE) placement and duct geometry on noise levels and flow dynamics. The results show that the presence of the HE smooths the upstream flow, improves rotor loading distribution and disrupts long, coherent vortical structures, thereby reducing tonal noise. However, the additional resistance introduced by the HE leads to increased rotor loading and enhanced leakage flow through the shroud-rotor gap. Despite these effects, the overall sound pressure level (OASPL) remains largely unchanged, maintaining a similar magnitude and dipolar directivity pattern as the configuration without the HE. In EV modules, the inclusion of ducts introduces significant flow disturbances and localized pressure fluctuations, leading to regions of high flow rate and rotor loading. These non-uniform flow conditions excite duct modes, resulting in troughs and humps in the acoustic spectrum and potentially causing resonance at the blade-passing frequency, which increases the amplitude in the lower frequency range. Analysis of the loading force components reveals that rotor loading is primarily driven by thrust forces, while duct loading is dominated by lateral forces. Across all configurations, fluctuations at the leading and trailing edges of the rotor are observed, originating from the blade tip and extending to approximately mid-span. These fluctuations are more pronounced in the EV module, identifying it as the dominant source of pressure disturbances. The numerical results are validated against experimental data obtained in the anechoic chamber at the University of Sherbrooke and show good agreement. The relative trends are accurately predicted at lower frequencies, with slight over-prediction, and closely match the experimental data at mid-frequencies. Full article

(This article belongs to the Special Issue Advances in Industrial Fan Technologies)

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Int. J. Turbomach. Propuls. Power, Volume 11, Issue 1 (March 2026) – 3 articles

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