Michele Marconcini

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• Mechanical Engineer, PhD
• Professor (Associate) at University of Florence

In low-pressure-turbines (LPT) at design point around 60-70% of losses are generated in the blade boundary layers far from end-walls, while the remaining 30%-40% is controlled by the interaction of the blade profile with the end-wall boundary layer. Increasing attention is devoted to these flow regions in industrial design processes. This paper dis...

Steady and unsteady CFD predictions of a state-of-the-art 11-stage axial compressor performances are compared with measurements and scrutinized to determine their ability to assist in the design phase. Unsteady calculations are capable of reproducing the measured stage loads and spanwise stagnation temperature and pressure profiles with good accura...

This paper presents an assessment of machine-learned turbulence closures, trained for improving wake-mixing prediction, in the context of LPT flows. To this end, a three-dimensional cascade of industrial relevance, representative of modern LPT bladings, was analyzed, using a state-of-the-art RANS approach, over a wide range of Reynolds numbers. To...

First stages of aeronautical high-pressure turbines are subjected to significant inlet distortions generated by the combustor system. These disturbances are characterized by velocity and temperature fluctuations convected downstream. Such perturbations are commonly defined as vorticity and entropy waves and interact with the turbine stages affectin...

This paper aims to evaluate the influence of numerical assumption in a Computational Fluid Dynamics (CFD) analysis for the preliminary design of gas turbines (GTs). In the early design phases steady state CFD analyses still represent a key tool for predicting GTs performance, thanks to the good balance between results accuracy and computational cos...

Artificial intelligence is a powerful tool across numerous scientific disciplines. Within turbomachinery, the application of Artificial Neural Networks (ANNs) stands out for its capacity to facilitate the optimization of stage components. ANNs can reveal complex nonlinear relationships between geometric features, which can pose challenges even for...

First stages of aeronautical high-pressure turbine are subjected to inlet distortions generated by the combustor systems. Such disturbances, characterized by velocity and temperature fluctuations, are referred to as vorticity and entropy waves and they are convected downstream by the main flow. Such disturbances interact with the turbine stages aff...

Centrifugal compressor aeromechanics is playing an increasingly important role in the energy transition scenario, especially when operating with low molecular weight gases, such as hydrogen. For these machines, maximum impeller tip speeds are limited by structural requirements and so aeromechanical assessment must be included from the preliminary d...

With the trend to full decarbonization, a full hydrogen economy development is a key industrial objective. Gas turbines, currently one of the cleanest fossil fuel-based power generation solutions, provide reliable and on-demand power. The introduction of hydrogen into the fuel mix of existing gas turbines represents a solution with great potential...

The paper describes the development of a novel transition/turbulence model based on the laminar kinetic energy concept. The model is intended as a base framework for data-driven improvements. Starting from a previously developed framework, mainly aimed at separated-flow transition predictions, suitable terms for model generalization are identified...

Aircraft noise is a polluting emission from civil aviation and is the most significant cause of adverse community reactions related to the operation and expansion of airports. Reducing the population affected by significant aircraft noise is therefore a key priority for aircraft-engine designers. Acoustic liners are a well-established technology to...

Previous studies have shown the potential of using a multiobjective CFD (computational fluid dynamics)-driven machine-learning approach to train both transition and turbulence models in RANS (Reynolds averaged Navier-Stokes) calculations for improved turbine flow predictions (Akolekar et al., GT2022-81091; Fang et al., GT2023-102902). However, cond...

Limiting the global warming impact requires a drastic reduction of greenhouse gas emissions (GHG) to reach a zero-carbon growth by 2050. Against this backdrop, turbomachinery designers are asked to develop more compact, efficient, and reliable machines. So, improving the power plants efficiency and operability. the research focuses on developing ma...

Mutual interaction of turbomachinery components plays a key role for comprehensive optimization of the machine. Among these interactions, the aerodynamic coupling between combustor systems and high-pressure turbine (HPT) stages may lead to aerodynamic performance degradation, combustion instability and noise generation. This interaction is mainly...

With the trend to full decarbonization, a full hydrogen economy development is a key industrial objective. Gas turbines, currently one of the cleanest fossil fuel-based power generation solutions, provide reliable and on-demand power. The introduction of hydrogen into the fuel mix of existing gas turbines represents a solution with great potential...

The damping behavior of compressor rotors is a key aspect for an accurate prediction of flutter and forced response vibrations. For the latter phenomenon, it is not rare that at Campbell’s crossings a relevant contribution to the overall damping comes directly from the fluid flow. This topic has been studied from a long time both to design flutter...

Centrifugal compressor aeromechanics is playing an increasingly important role in the energy transition scenario, especially when operating with low molecular weight gases, such as hydrogen. For these machines, maximum impeller tip speeds are limited by structural requirements and so aeromechanical assessment must be included from the preliminary d...

In this paper novel machine-learnt transition and turbulence models are applied to the prediction of boundary-layer transition and wake-mixing in a Low-Pressure Turbine (LPT) cascade, including unsteady inflow cases with incoming wakes. A Laminar Kinetic Energy (LKE) transport approach is employed as baseline transition framework. The application o...

Dear Colleagues, Turbine and compressor performance is a crucial aspect in terms of increasing efficiency and reducing emissions for multiple applications, such as aeroengines and power-generation systems. The manufacturers of aircraft engines, gas turbines or industrial compressors are forced to pursue interdisciplinary design approaches involvin...

When it comes to modern design of turbomachinery, one of the most critical objectives is to achieve higher efficiency and performance by reducing weight, fuel consumption, and noise emissions. This implies the need for reducing the mass and number of the components, by designing thinner, lighter, and more loaded blades. These choices may lead to me...

The study of component interactions in aeronautical engines is a key aspect to improve the aerodynamic, aeromechanical and thermal performance and to reduce greenhouse gas and noise emissions. In this context, combustor systems generate pressure, velocity and temperature fluctuations that interact with the turbine module producing combustor instabi...

No common laminar kinetic energy (LKE) transition model has to date been able to predict both separation-induced and bypass transition, both phenomena commonly found in low-pressure turbines (LPT) and high-pressure turbines (HPT). Here, a data-driven approach is adopted to develop a more general LKE transition model suitable for both transition mod...

Energy transition has become one of the most discussed topics of the current times. Turbomachinery still plays a key role in the power generation field, but the machines must meet very high standards in terms of performance levels, compactness, and cost reduction. In this perspective, new design configurations need to be explored. This paper presen...

In order to face the challenges of energy transition, turbomachinery designers claim for appropriate numerical tools able to keep up with robust, and fast design iterations. High fidelity analyses are becoming feasible for assessing the performance of selected geometries, however RANS-based CFD codes are still the workhorse exploited for daily des...

Due to their good efficiency, robustness, and wide operating range, centrifugal compressors are pivotal in several industrial and civil applications. In this context, predicting the performance of a centrifugal compressor stage is essential for its aerodynamic design and selection during customer orders. Therefore, the present research focuses on p...

The study presents a combined experimental and numerical analysis of the impact of external losses in defining the real performance of a model stage. This is of particular importance in the early-validation phase, where novel solutions going beyond the state of the art need to be verified for the first time. Due to the number of simulations to be c...

Centrifugal compressors are suited for high pressure applications. Generally, many centrifugal compressor stages are stacked together in order to guarantee the overall pressure ratio implying larger machines. With the aim of more compact machines, it is possible to design high pressure ratio stages, thus reducing the total number of stages. In this...

In this paper novel machine-learnt transition and turbulence models are applied to the prediction of boundary-layer transition and wake-mixing in a Low-Pressure Turbine (LPT) cascade, including unsteady inflow cases with incoming wakes. A Laminar Kinetic Energy (LKE) transport approach is employed as baseline transition framework. The application o...

The study of component interactions in aeronautical engines is a key aspect to improve the aerodynamic, aeromechanical and thermal performance and to reduce greenhouse gas and noise emissions. In this context, combustor systems (working with lean and premixed flames) generate pressure, velocity and temperature fluctuations that interact with the tu...

The present paper aims at investigating the effect of part-span snubber applied on the last rotor of an industrial steam turbine. The large increase in steam specific volume during the expansion forces low pressure turbine designers to develop high aspect ratio blades for the last stage. Considering also the relatively low thickness of the airfoil...

The laminar kinetic energy (LKE) transition model has been proposed to predict the separation-induced transition, which is frequently experienced by low pressure turbines (LPT). In contrast to LPTs, high-pressure turbines (HPT) often are subject to bypass transition which currently is not captured well when using the LKE model. Because these two ty...

In previous studies, the highly-loaded, low-pressure turbine T106C has been used as a validation test case for direct numerical and large-eddy simulation codes. In contrast to the experimental test campaign, previous high-fidelity simulations simplify the cascades’ geometry by considering only a fraction of the spanwise extent with periodic boundar...

In order to increase the impact of cascade tests on the design of low-pressure turbines (LPT) at engine level, the end-wall geometry must be taken into account. Even if, given the high aspect ratio of LPT bladings, profile loss is expected to be the major loss source, the evolving secondary flow phenomena in the end-wall region can contribute up to...

The massive growth of the air traffic during the last years is leading to stricter limitations on the noise emission levels radiated from aircraft engines. To face this issue, the installation of acoustic liners on the intake duct and the exhaust nozzles is a common strategy adopted to properly abate noise emissions coming from the fan, the compres...

The development of novel conversion technologies for recovering waste heat is one of the technical goals of the European Commission, considering the large amount of thermal energy discharged by industrial processes in Europe. The recently launched EU-H2020 project CO2OLHEAT aims at contributing to industrial waste heat recovery by developing a nove...

The increasing demand for robust and high-performance centrifugal compressor stages has led to the development of several optimization and uncertainty quantification approaches. However, in the industrial scenario, geometric variations of such pre-engineered stages can occur during customer orders or non-conformity evaluations. In this regard, a ra...

Heterogeneous computing is the major driving factor in designing new energy-efficient high-performance computing systems. Despite the broad adoption of GPUs and other specialized architectures, the interest in spatial architectures like field-programmable gate arrays (FPGAs) has grown. While combining high performance, low power consumption and hig...

The increasing importance of renewable energy capacity in the power generation scenario, together with the fluctuating consumer energy demand, forces conventional fossil fuel power generation systems to promptly respond to relevant and rapid load variations and to operate under off-design conditions during a major fraction of their lives. In order...

Despite the ongoing COVID-19 pandemic, the latest forecasts about air traffic in Europe are predicting a recovery to the 2019 levels by the next two years. Since noise pollution of urban areas close to airports is a serious issue, international regulations are more and more oriented to restrict the maximum allowable aircraft noise. A viable strateg...

With the growing importance of renewable energy, the interest in energy-harvesting technologies based on flow-induced vibrations of airfoils has been rekindled in the past few years. Compared to conventional turbines, these devices are centrifugal stress-free and hence they are structurally more robust. They are also environmentally friendly due to...

Limiting the global warming impact requires a drastic reduction of greenhouse gas emissions (GHG) to reach a zero-carbon growth in the next decades. In this context, the research focuses on developing machines able to reduce energy losses, thus improving power plants efficiency. To this end, expander-compressors (EC) seem to play a key role in the...

Aircraft engine designers are nowadays facing more and more challenges: they strive to reduce fuel consumption, obtain better engine performance, and create quieter, safer, and environmentally friendlier products. One of the key factors to achieve these goals is the availability of numerical simulation tools able to accurately predict engine behavi...

First stages of aeronautical high-pressure turbines are subjected to significant inlet distortions generated by the combustor system. These disturbances are characterized by velocity and temperature fluctuations convected downstream by the flow. Such perturbations are commonly defined as vorticity and entropy waves and interact with the turbine sta...

The massive growth of the air traffic during the last years is leading to stricter limitations on the noise emission levels radiated from aircraft engines. To face this issue, the installation of acoustic liners on the intake duct and the exhaust nozzles is a common strategy adopted to properly abate the noise emissions coming from the fan, the com...

When it comes to turbomachinery, modern design trend has always been to decrease the number of stages and blade count, leading to thinner, lighter, and more loaded blades, while maintaining high efficiency and performance. This trend however may lead to mechanical issues caused by fluid-structure interaction, such as flutter and forced response. Th...

The design of turbomachines is a long iterative process, which involves several teams and disciplines. Hence, a lot of efforts are put on making it as smooth and accurate as possible in order to reduce the time-to-market. On this premise, this paper introduces a procedure aimed at improving the aerodynamic design process of radial-inflow turbines f...

The present paper is part of a two-part publication that aims to numerically investigate the occurrence of flow induced vibrations in a steam turbine last stage rotor at low load operations. Experimental and numerical investigations of low load operating conditions are raising in interest for the design of steam turbine blades due to the required e...

Limiting global warming’s effects requires a sudden reduction of greenhouse gas emissions to pursue a net-zero carbon growth in the next decades. Along with this energy transition, drastic and rapid changes in demand are expected in many sectors, including the one for centrifugal compressors. In this context, new aerodynamic design processes exploi...

This paper describes a coupled experimental and CFD campaign conducted on a 1.5 intermediate turbine stage in the full range of operating conditions, from start-up to design point under variable expansion ratio and physical speed. The test maintains engine similitude conditions and allows direct comparison with CFD data to assess the predictions ac...

This article reports a detailed experimental and numerical study of the clocking effect between entropy wave spots and stator leading edges on the evolution of the entropy wave and on indirect noise generation in a high pressure turbine stage. Experimental campaigns considering burner-representative temperature fluctuations injected upstream of an...

The increasing introduction of renewable energy capacity has changed the perspective on the operation of conventional power plants, introducing the necessity of reaching extreme off-design conditions. There is a strong interest in the development and optimization of technologies that can be retrofitted to an existing power plant to enhance flexibil...

Avio Aero is one of GE Aviation’s businesses at the forefront of developing innovative aeronautic design technologies that are transforming the engineering and production of aeronautical components and modules for next-generation greener and quieter engines. In this context, nowadays there are significant efforts being made to get increasingly reli...

Magazine article published in PLATINUM “Aziende & Protagonisti”. (https://platinum-online.com/pubblicazioni). University of Florence involvement in the European Project ARIAS (Advanced Research Into Aeromechanical Solutions, https://www.arias-project.eu) In order to save fuel, achieve zero emissions thanks to hydrogen and improve performance, th...

The paper describes a numerical method based on modal work approach to evaluate the forced response of bladed disks and its validation against numerical results obtained by a commercial FEM code. Forcing function caused by rotor/stator interactions are extracted from CFD unsteady solution properly decomposed in time and space to separate the spinni...

Centrifugal compressor stages with high rotor stiffness (i.e.impeller hub-to-outer-diameter ratio) may represent a crucial element to cope with tight rotordynamic requirements and constraints that are needed for certain applications. On the otherhand, high stiffness has a detrimental effect on the aerodynamicperformance. Thus, an accurate design an...

This paper describes the transport and the interaction of entropy waves generated by combustor burners within a HP turbine stage. Experiments and CFD simulations were carried out in the context of the EU Project RECORD. Experimental campaigns considering burner representative temperature fluctuations at the stage inlet have been performed in the te...

The increasing introduction of renewable energy capacity has changed the perspective of operation of conventional power plants introducing the necessity of reaching extreme off-design conditions. There is a strong interest in the development and optimization of technologies, that can be retrofitted to an existing power plant to enhance flexibility,...

With the increasing importance of renewable energy sources in the power generation scenario, traditional fossil-fuel power generation systems are subjected to relevant and rapid load variations. Consequently, designers have become more and more interested at predicting the transient behavior of fossil fuel power plants. Tools allowing off-design pe...

The working conditions of airfoils along modern wind turbine blades are putting new focus on the importance of properly characterizing the aerodynamic performance of different airfoil families also at high angles of attack (AoAs) beyond stall and at Reynolds numbers much lower (from few thousands to one million) than those commonly analyzed before....

The tip leakage flow in turbine and compressor blade rows is responsible for a relevant fraction of the total loss. It contributes to unsteadiness, and have an important impact on the operability range of compressor stages. Experimental investigations and, more recently, scale-resolving CFD approaches have helped in clarifying the flow mechanism de...

This paper describes the transport and the interaction of pulsating entropy waves generated by combustor burners within a high pressure turbine stage for aeronautical application. Experiments and Computational Fluid Dynamics (CFD) simulations were carried out in the context of the European Research Project RECORD. Experimental campaigns considering...

This paper describes a coupled experimental and CFD campaign conducted on a 1.5 intermediate turbine stage in the full range of operating conditions, from start-up to design point under variable expansion ratio and physical speed. The test maintains engine similitude conditions and allows direct comparison with CFD data to assess the predictions ac...

In the last decades, the consolidation of 3D CFD approaches in the industrial design practices has progressively moved throughflow codes from the top of design systems to somewhere in between first development stages and the final aerodynamic optimizations. Despite this trend and the typical limitations of traditional throughflow methods, designers...

This paper discusses the migration, the interaction with the blades, and the attenuation of hot streaks generated by combustor burners, during their propagation within the first turbine stage of aero-engines. Experiments and Computational Fluid Dynamic (CFD) simulations were carried out in the framework of the European Project RECORD and on its fol...

In this work, the effects of Turbine Center Frame (TCF) wakes on the aeromechanical behavior of the downstream Low Pressure Turbine (LPT) blades are numerically investigated and compared with experimental data. A small industrial gas turbine has been selected as a test case, composed of a TCF followed by the two low pressure stages and a Turbine Re...

In low-pressure-turbines (LPT) around 60-70% of losses are generated away from end-walls, while the remaining 30-40% is controlled by the interaction of the blade profile with the endwall boundary layer. Experimental and numerical studies have shown how the strength and penetration of the secondary flow depends on the characteristics of the incomin...

A CFD-based throughflow solver is applied to the meridional analysis of low-pressure steam turbine modules. The throughflow code inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code) and incorporates real gas capabilities, three-dimensional flow features and spanwise mixing models. Secondary flow effects are introduced via a...

A CFD-based throughflow solver is applied to the meridional analysis of low-pressure steam turbine modules. The throughflow code inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code) and incorporates real gas capabilities, three-dimensional flow features and spanwise mixing models. Secondary flow effects are introduced via a...

The study of inlet flow distortion (hot streaks and entropy waves) propagation through high-pressure turbine (HPT) stages is an open topic for aero-engine design, due to their multiple effects on aerodynamics, heat exchange and noise generation. The request to design compact and lightweight systems has recently led to a reduction of the combustor-t...

This paper presents an innovative design for reducing the impact of secondary flows on the aerodynamics of low-pressure turbine (LPT) stages. Starting from a state-of-the-art LPT stage, a local reshaping of the stator blade was introduced in the end-wall region in order to oppose the flow turning deviation. This resulted in an optimal stator shape,...

In this paper, the AUSM+-up scheme is compared to other numerical flux schemes in the framework of a RANS/URANS code for turbomachinery applications. The considered advection schemes include central discretizations with artificial dissipation and the Roe upwind scheme. The comparison is carried out by studying a low-aspect-ratio turbine cascade ove...

In this work, the effects of Turbine Center Frame (TCF) wakes on the aeromechanical behavior of the downstream Low Pressure Turbine (LPT) blades are numerically investigated and compared with experimental data. A small industrial gas turbine has been selected as a test case, composed of a TCF followed by the two low pressure stages and a Turbine Re...

This paper discusses the migration, the interaction with the blades, and the attenuation of hot streaks generated by combustor burners, during their propagation within the first turbine stage of aero-engines. Experiments and Computational Fluid Dynamic (CFD) simulations were carried out in the framework of the European Project RECORD and on its fol...

This paper presents an innovative design for reducing the impact of secondary flows on the aerodynamics of low-pressure turbine (LPT) stages. Starting from a state-of-the-art LPT stage, a local reshaping of the stator blade was in- troduced in the end-wall region in order to oppose the flow turning deviation. This re- sulted in an optimal stator sh...

ARCTIC, a novel incompressible Reynolds–averaged Navier–Stokes finite volume code for the hydrodynamic analysis of open rotor unsteady loads is presented. One of its unique features is a harmonic balance solver enabling high–fidelity analyses of turbine periodic hydrodynamic loads with runtimes reduced by more than one order of magnitude over conve...

The current industrial standard for numerical simulations of axial compressors is the steady Reynolds-averaged Navier–Stokes (RANS) approach. Besides the well-known limitations of mixing planes, namely their inherent inability to capture the potential interaction and the wakes from the upstream blades, there is another flow feature which is lost, a...

This work presents a simplified procedure to design a flutter free airfoil geometry for aeroderivative gas turbine stator blade rows. The common workflow for a fully 3D flutter numerical assessment with an uncoupled method firstly involves a FE modal analysis to obtain the airfoil mode shapes which will be used for unsteady aeroelastic computations...

Due to the low level of profile losses reached in low-pressure turbines (LPT) for turbofan applications, a renewed interest is devoted to other sources of loss, e.g., secondary losses. At the same time, the adoption of high-lift profiles has reinforced the importance of these losses. A great attention, therefore, is dedicated to reliable prediction...

In this article the parametric design of centrifugal pumps is addressed. To deal with this problem, an approach based on coupling expensive Computational Fluid Dynamics (CFD) computations with Artificial Neural Networks (ANN) as a regression meta-model had been proposed in Checcucci et al. (2015), "A Novel Approach to Parametric Design of Centrifug...

In response to the continuous increase in aircraft noise pollution, computational aeroacoustic analyses are mandatory during the aero-engine design loop. In order to investigate the acoustic generation and propagation phenomena within a multi-stage turbomachinery, an experimental campaign on direct and indirect noise coming from a high pressure axi...

The importance of considering the unsteady effects in aeronautical engine design has brought to the implementation of simplified unsteady CFD models to respect the temporal restrictions of design cycles. A comparison among steady, Non-Linear Harmonic(NLH) and Full-Annulus (FA) methods has been carried out analyzing the transonic turbine stage CT3,...

The paper presents the theoretical bases and an application of a CFD-based Through-Flow model. The code solves the axisymmetric Euler equations and takes into account the effect of tangential blockage and body force. It inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code). Blade body forces are calculated directly from the t...

In low-pressure-turbines (LPT) at design point around 60-70% of losses are generated in the blade boundary layers far from end-walls, while the remaining 30%-40% is controlled by the interaction of the blade profile with the end-wall boundary layer. Increasing attention is devoted to these flow regions in industrial design processes. Experimental t...

In low-pressure-turbines (LPT) around 60-70% of losses are generated away from end-walls, while the remaining 30-40% is controlled by the interaction of the blade profile with the end-wall boundary layer. Experimental and numerical studies have shown how the strength and penetration of the secondary flow depends on the characteristics of the incomi...

Due to the generally high stage and blade count, the current standard industrially adopted to perform numerical simulations on multistage axial compressors is the steady-state analysis based on the Reynolds-averaged Navier-Stokes approach (RANS), where the coupling between adjacent rows is handled by means of mixing planes. In addition to the well-...

Due to the low level of profile losses already reached in the design of modern low-pressure turbines for turbofan applications, a renewed interest is devoted to the other sources of loss, and namely to the secondary losses. At the same time, the importance of secondary losses has been reinforced by the current design trend towards high-lift profile...

Multistage axial compressors have always been a great challenge for designers since the flow within these kind of machines, subjected to severe diffusion, is usually characterized by complex and widely developed 3D structures, especially next to the endwalls. The development of reliable numerical tools capable of providing an accurate prediction of...

The paper describes the development and validation of a novel CFD-based throughflow model. It is based on the axisymmetric Euler equations with tangential blockage and body forces and inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code). Secondary and tip leakage flow features are modelled in terms of Lamb-Oseen vortices and...

The paper describes the development and validation of a novel CFD-based throughflow model. It is based on the axisymmetric Euler equations with tangential blockage and body forces and inherits its numerical scheme from a state-of-the-art CFD solver (TRAF code). Secondary and tip leakage flow features are modelled in terms of Lamb-Oseen vortices and...

An accurate characterization of rotating stall in terms of inception modality, flow structures, and stabilizing force is one of the key goals for high-pressure centrifugal compressors. The unbalanced pressure field that is generated within the diffuser can be in fact connected to a non-negligible aerodynamic force and then to the onset of detriment...

Rotating stall in centrifugal compressors not only adversely affects the performance before surge, but also can generate high subsynchronous vibrations, marking the minimum flow limit of a machine. Recent works presented an experimental approach to estimate the stall force induced by the unbalanced pressure field in a vaneless diffuser from dynamic...

An accurate characterization of rotating stall in terms of inception modality, flow structures, and stabilizing force is one of the key goals for high-pressure centrifugal compressors. The unbalanced pressure field that is generated within the diffuser can be in fact connected to a non-negligible aerodynamic force and then to the onset of detriment...

The rotational speed of low pressure turbines (LPT) for geared turbofan applications is significantly increased looking for potential benefit in performance, weight and overall dimensions. As a drawback, the high speed LPT are characterized by critical mechanical constraints due to the large centrifugal stresses in conjunction with the use of light...

The present activity was carried out in the framework of the Clean Sky European Research Project ITURB (optimal high-lift turbine blade aeromechanical design), aimed at designing and validating a turbine blade for a geared open-rotor engine. A cold-flow, large-scale, low-speed (LS) rig was built in order to investigate and validate new design crite...

The paper describes the development and validation of a novel CFD-based throughflow model. It is based on the axisymmetric Euler equations with tangential blockage and body forces and inherits its numerical scheme from state-of-the-art CFD solver (TRAF code), including real-gas capabilities. A crucial aspect of the numerical procedure is represente...

The aerodynamic performance of a high-load low-pressure turbine blade cascade has been analyzed for three different distributed surface roughness levels (Ra) for steady and unsteady inflows. Results from CFD simulations and experiments are presented for two different Reynolds numbers (300000 and 70000 representative of take-off and cruise condition...