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In the coming carbon-neutral era, industrial gas turbines (GT) will continue to play an important role as energy conversion equipment with high thermal efficiency and as stabilizers of the electric power grid. Because of the transition to a clean fue...

This study targets determining impellers of impeller-only axial fans with an optimal hub-to-tip ratio for the highest achievable total-to-static efficiency. Differently from other studies, a holistic approach is chosen. Firstly, the complete class of...

Unsteady component interaction represents a crucial topic in turbomachinery design and analysis. Combustor/turbine interaction is one of the most widely studied topics both using experimental and numerical methods due to the risk of failure of high-p...

The complex flow conditions in Pelton turbines make it challenging to gain detailed insight into the local flow processes. However, CFD methods offer vast potential for developing and optimising Pelton turbines due to these flow conditions. In a comp...

The rising number of applications of the organic Rankine cycle (ORC) or supercritical CO₂ (sCO₂) power systems have shaped a new branch of fluid mechanics called non-ideal compressible fluid dynamics (NICFD). This field of fluid mechanics is concerne...

In modern turbofan engines, the bypass section of the fan stage alone provides the majority of the total thrust required in cruise, and the size of the fan has a considerable effect on the overall engine weight and nacelle drag. Thrust requirements i...

The present paper is aimed at providing an updated review of prediction methods for the aerodynamic noise of ducted rotor–stator stages. Indeed, ducted rotating-blade technologies are in continuous evolution and are increasingly used for aerona...

In applications, the acoustics of fans can differ significantly from the measurements of the standalone fan. This is due to disturbed inflow conditions, for example, caused by a heat exchanger upstream of an axial fan. Resolving the complex geometry...

Predicting pump performance and ensuring operational reliability under two-phase conditions is a major goal of three-dimensional (3D) computational fluid dynamics (CFD) analysis of liquid/gas radial centrifugal pump flows. Hence, 3D CFD methods are i...

The present study introduces a conceptual design of a small axial-flow fan. Both individual and combined effects of blade stagger angle and winglet on the performance of the fan design are investigated in design and off-design operating conditions us...

Supercritical carbon dioxide (sCO₂) can be mixed with dopants such as titanium tetrachloride (TiCl₄), hexafluoro-benzene (C₆F₆), and sulphur dioxide (SO₂) to raise the critical temperature of the working fluid, allowing it to condense at ambient temp...

Due to the increasingly high turbine inlet temperatures, heat transfer analysis is now, more than ever, a vital part of the design and optimization of high-pressure turbine rotor blades of a modern jet engine. The present study aimed to find out how...

The successful design of compressor blades through numerical optimization relies on accurate CFD-RANS solvers that are able to capture the general performance of a given design candidate. However, this is a difficult task to achieve in transonic flow...

In this paper, we present the design and optimization of a centrifugal fan with requirements of maximizing the total-to-static pressure rise and total-to-static efficiency at two operating points and the maximum torque provided by the motor power usi...

This paper aims to summarize the results of several experimental investigations regarding two-phase liquid–gas flows in radial centrifugal pumps. The main objective is to combine the corresponding experimental results and collect the obtained k...

In the quest to enhance the efficiency of gas turbines, there is a growing demand for innovative solutions to optimize high-pressure turbine blade cooling. However, the traditional methods for achieving this optimization are known for their complexit...

Double-Wall Effusion Cooling schemes present an opportunity for aeroengine designers to achieve high overall cooling effectiveness and convective cooling efficiency in High-Pressure Turbine blades with reduced coolant usage compared to conventional c...

Numerical optimization methods are widely used for designing turbomachinery components due to the cost and time savings they can provide. In the available literature, the shape optimization of radial compressors mainly focuses on improving the impell...

This paper presents a numerical analysis of the influence of the von Karman vortex shedding at the blade trailing edge on the hydrodynamics of a recently installed small hydro Francis turbine manifesting very loud and high-frequency acoustic pulsatio...

The acoustic properties of a single-stage centrifugal pump with low specific speed are investigated by means of compressible 3D CFD simulations (URANS) and experiments. In order to determine the pump’s acoustic transmission and excitation chara...

The bursting phenomenon consists in the switch of a laminar separation bubble from a short to a long configuration. In the former case, reduced effects on profile pressure distribution are typically observed with respect to the attached condition. On...

The surge limit of centrifugal compressors is a key parameter in the design process of modern turbochargers. Numerical methods like steady-state simulations are state-of-the-art methods for predicting the performance of the centrifugal compressor. In...

A numerical study was conducted to identify the mechanisms involved in the destabilisation of centrifugal compressors with vaneless diffusers. A stability analysis—carried out on the rotating and fixed parts of the studied machines—showed...

Automotive fans, small wind turbines, and manned and unmanned aerial vehicles (MAVs/UAVs) are just a few examples in which noise generated by the flow’s interaction with aerodynamic surfaces is a major concern. The current work shows the potent...

This paper presents experimental measurements of adiabatic effectiveness for three transpiration cooling porosities ($\varphi =$ 0.3, 0.4, and 0.5) constructed from gyroid lattice structures. To the authors’ knowledge, this is the first use of a Tr...

Experimental monitoring of blade vibration in turbomachinery is typically based on blade-mounted strain gauges. Their signals are used to derive vibration amplitudes which are compared to modal scope limits, including a safety factor. According to in...

The present work examines the capabilities of two transition models implemented in ANSYS Fluent in the open-water performance prediction of a rim-driven thruster (RDT). The adopted models are the three-equation $k-k_L-\omega$ and the four-e...

In this study, a thorough experimental investigation of the synchronous blade vibrations of a radial turbine is performed for different IGV configurations. First, the blade modes are measured experimentally and calculated numerically. Subsequently, t...

Wall proximity affects the accuracy of pressure probe measurements with a particularly strong impact on multi-hole probes. The wall-related evolution of the calibration of two hemispheric L-shaped 3D-printed five-hole probes was investigated in a low...

This paper deals with large onshore wind turbine aeroacoustics. Noise from the NREL 5 MW device is predicted by the permeable-surface Ffowcs Williams–Hawkings equation (FWH-P), starting from the postprocessing of LES data on different acoustic...

In this paper, an experimental and numerical investigation of the effect of leading-edge erosion in transonic blades was performed. The measurements were carried out on a linear blade cascade in the Transonic Cascade Wind Tunnel of DLR in Cologne at...

In rotating detonation engines the turbine inlet conditions may be transonic with unprecedented unsteady fluctuations. To ensure an acceptable engine performance, the turbine passages must be suited to these conditions. This article focuses on design...

Turbine blades for modern turbomachinery applications often exhibit complex twisted designs that aim to reduce aerodynamic losses, thereby improving the overall machine performance. This results in intricate internal cooling configurations that chang...

Aviation accounts for a significant share of global CO₂ emissions, necessitating efficient propulsion technologies to achieve net-zero emissions by 2050. Geared turbofan architectures offer a promising solution by enabling higher bypass ratios and im...

In many air conditioning applications fan arrays offer an increasingly popular alternative to single large fans due to redundancy and ease of maintainability. Additionally, there is the possibility to dynamically resize the array by selectively turni...

Erosion damage can occur in fans and blowers during industrial processes, cooling, and mine ventilation. This study focuses on investigating erosion caused by particulate air flows in a centrifugal fan with forward-inclined blades. This type of fan i...

A numerical method using combined detached-eddy simulation (DES) and a cavitation model considering the rotation effect is used for unsteady cavitation flow field of the centrifugal pump. A closed-type pump test system was established to obtain the p...

Turbulence intensity impacts the performance of turbine stages and it is an important inlet boundary condition for CFD computations; the knowledge of its value at the turbine inlet is then of paramount importance. In combustor–turbine interacti...

The aerodynamics of a high-speed low-pressure turbine (LPT) cascade were investigated under steady and unsteady inlet flows. The tests were performed at outlet Mach (M) and Reynolds numbers ($Re$) of $0.90$ and 70k, respectively. Unsteady wakes were simu...

The influence of unsteady wakes incoming from the upstream stages is of high relevance in modern high-speed, low-pressure turbines (LPT) operating at transonic exit Mach numbers and low Reynolds numbers for their potential to trigger transition and i...

A growing significance of flexible steam turbine operation challenges the control of turbines, as part load operation using control valves can be accompanied by highly unsteady flow conditions. The increased dynamic load induced by pressure forces ca...

A turbine vane frame is a special type of intermediate turbine duct, and is one option to improve the efficiency and reduce the length and weight of an aero-engine. However, due to its geometry, it features a complex flow field, and therefore in-dept...

The increasing utilisation of demand-controlled ventilation strategies leads to the frequent operation of fans under part-load conditions. To accurately predict the energy demand of a ventilation system with a fan array in the early design stages, mo...

Labyrinth seals are commonly used in turbomachinery in order to control leakage flows. Flutter is one of the most dangerous potential issues for them, leading to High Cycle Fatigue (HCF) life considerations or even mechanical failure. This phenomenon...

Considerable progress has been achieved in recent decades in understanding the phenomena related to the onset of condensation in steam flows, both experimentally and especially numerically. Nevertheless, there is still a certain disagreement between...

The design complexity of the new generation of civil aero-engines results in higher demands on engines’ components, higher component temperatures, higher heat generation, and, finally, critical thermal management issues. This paper will propose...

A cost-effective solution to address the challenges posed by sensitive instrumentation in next-gen turbomachinery components is to reduce the number of measurement samples required to assess complex flows. This study investigates Gaussian Process (GP...

Air-cooled condensers (ACCs) are commonly found in power plants working with concentrated solar power or in steam power plants operated in regions with limited water availability. In ACCs, the flow of air is driven toward the heat exchangers by axial...

The purpose of the paper is to characterize the aerodynamic behavior of a rotor-downstream hub cavity rim seal in a high-pressure turbine (HPT) stage. The experimental data are acquired in the Transonic Test Turbine Facility at the Graz University of...

Helicopter and turboprop engines are susceptible to the ingestion of debris and other foreign objects, especially during take-off, landing, and hover. To avoid deleterious effects, filters such as Inlet Particle Separators (IPS) can be installed. How...