Hua-Dong Yao

• PhD
• Professor at Chalmers University of Technology

Increase of train speed intensifies the interaction between the pantograph–overhead contact system (OCS) and the high-speed airflow, amplifies the pantograph vortex-induced vibration, degrades the pantograph–OCS interaction, and reduces the quality of the current collection, which is difficult to simulate. In this study, the user defined function i...

A wave energy converter (WEC) comprises many components with distinct functions. The whole WEC system is complicated, as each component is also a complex subsystem. It is challenging to properly model and couple these subsystems to achieve a global simulation of the whole system. This study proposes an FMI-based co-simulation framework to tackle th...

Data-driven approaches offer novel opportunities for improving the performance of turbulent flow simulations, which are critical to wide-ranging applications from wind farms and aerodynamic designs to weather and climate forecasting. However, current methods for these simulations often require large amounts of data and computational resources. Whil...

The noise generated from cooling fans in heavy-duty vehicles like trucks poses challenges regarding environmental pollution and overall user comfort. To solve this problem, this study develops an acoustic metamaterial (AMM) that is constructed with small Helmholtz resonators in two layers. This concept can attenuate the noise in a broad frequency r...

Bifurcated tunnels have many lines that significantly improve the utilization of underground space. However, the pressure waves (PWs) generated by a metro train in a tunnel may cause irreversible damage to the tunnel, particularly the more complex wave system generated by a train in a variable cross section bifurcated tunnel. Overset grid technolog...

To meet the International Maritime Organization's (IMO) goal of decarbonising the shipping sector by 2050, zero-emission ship propulsion systems should be developed to replace conventional fossil fuel-based ones. In this study, we propose a zero-emission hybrid hydrogen-wind-powered propulsion system to be retrofitted to a benchmark merchant ship w...

In maritime engineering, ensuring vessel stability remains a paramount concern. This study investigates the hydrodynamic response of Magnus anti-rolling devices, modeled as swinging or slewing rotating cylinders, under a ship's rolling motion. Through numerical simulations using the overset mesh technique and large eddy simulation, we analyze vario...

The use of wind-assisted ship propulsion is regarded as one of the effective ways to reduce greenhouse gas emissions. This study combines wind tunnel experiments and advanced numerical simulations to investigate the model-scale effects and fluid-structure interaction (FSI) of a wingsail with a crescent-shaped profile. First, a wind tunnel test is c...

The finite-length rotating column has been extensively studied because of its importance in various fields, such as marine and aerospace. In this study, the hydrodynamic performance of a finite-length rotating column with two free ends at different angles of attack is investigated using a large eddy simulation method. The effects of various geometr...

Numerical analyses are presented for two generations of a floating heaving point absorber wave energy converter (WEC) installed with different farm array layouts. The wave farm configurations are based on WECs developed by Waves4Power. The numerical models are developed in the DNV software package, Sesam. Parametric studies of the isolated WEC conf...

Wingsails as a classical means for wind-assisted ship propulsion is booming today. Crescent-shaped wingsails have shown great potential considering their aerodynamics in thrust generation. However, there have been few studies on its structural responses exposed to unsteady aerodynamic loads. In this study, a crescent-shaped wingsail at a \(1:100\)...

Interactions between wave energy converters (WECs) can significantly affect the overall energy-harnessing performance of a wave park. Although large-size wave parks with many WEC units are commonly considered in practical applications, it is challenging to simulate such parks due to huge computational costs. This paper presents a numerical model th...

To understand passive vortex-induced vibrations (VIV) coexisting with active structure motions, this paper numerically investigates the use of pure pitch oscillation to control a square cylinder mounted with a deformable splitter plate at the Reynolds number of 333. The oscillation is enforced with an amplitude of 3° and different frequencies from...

The test speed of high-speed maglev trains (HSMT) exceeds 600 km/h, requiring higher braking performance and technology. Plate braking technology, which is a suitable choice, has been applied for engineering the high-speed test vehicles. However, the unsteady aerodynamic response during the opening process of HSMT under crosswind needs to be studie...

In this paper, the flow field between two vibrating systems and the potential to increase the harvested energy by the interference of flow fields was numerically evaluated. A combined configuration of a cylinder-splitter hyperelastic plate placed at the wake of a vortex-induced oscillating cylinder was studied in a laminar channel flow at a Reynold...

Inspired by the silent gliding feather of owl wings, the trailing edge of the duct of a pump-jet propulsor was designed with a similar serrated structure in order to reduce noise generation. Two distinct serrated structures were proposed and evaluated using the detached eddy simulation method with the shear stress transport k − ω turbulence model....

Over the years, several research projects have evaluated different concepts for wind-assisted propulsion, generally concluding that it can lead to significant fuel savings. The time-averaged propulsive performance of a single rigid wingsail has been analysed in previous studies. However, the unsteady characteristics of the external loads which may...

When employing rotating cylinders as ship anti-rolling devices based on the Magnus effect, the cylinders are near the free surface. However, most of the previous studies on rotating cylinders considered single-phase (SP) flows, where the interaction between the free surface and rotating cylinders was missing. In this study, we explore a rotating cy...

This study introduces a concept that jet technology in the aeronautical field is used for active flow control to improve the hydrodynamic performance of a ducted propeller. Jet flow is added in front of the ducted propeller, and it produces a circumferential velocity that is opposite to the rotation direction of the rotor. An international standard...

Rim-driven thrusters (RDT) are of great interest for the development of integrated electric motors for underwater vehicles. Gap flow is one of the most prominent flow characteristics and plays an important role in the hydrodynamic performance of RDT. In this study, the rim in a carefully designed RDT was modified with several concave cavities defin...

Wind-assisted ship propulsion is considered an effective method for reducing greenhouse gas emissions. This paper presents numerical analyses of the aerodynamics of a single rigid wingsail conducted using the unsteady Reynolds-averaged Navier-Stokes (uRANS) equations. The wingsail is designed with a new sectional profile: a crescent-shaped foil. Th...

To reduce the aerodynamic drag of high-speed trains, this work proposes an air blowing configuration on the head and tail cars of high-speed trains. The variation in the aerodynamic drag and slipstream velocity is analyzed under different blowing velocities, and the flow mechanism for train aerodynamic performance alteration is explained. The resul...

The production of renewable energy is key to satisfying the increasing demand for energy without further increasing pollution. Harnessing ocean energy from waves has attracted attention due to its high energy density. This study compares two generations of floating heaving point absorber WEC, WaveEL 3.0 and WaveEL 4.0, regarding their power perform...

Aerospace, an open access journal operated by MDPI, recently released a Special Issue entitled “Aeroacoustics and Noise Mitigation” [...]

This paper presents a study of the oil flow in a vertically arranged FZG gearbox. The splash and churning losses are experimentally evaluated using measurements of the resistance torque. Using high speed imaging, the instantaneous oil splashing inside the gearbox is also presented and compared with Computational Fluid Dynamics (CFD) results from th...

Deploying wave energy converters (WECs) in wave parks into the ocean requires detailed planning and numerical analyses to maximize the wave energy capture and keep the LCoE at the lowest possible level. High-fidelity simulation models can accurately simulate the fluid-structure interaction (FSI) between the WECs and the ocean's waves. However, the...

The synthetic turbulence generator (STG) lies at the interface of the Reynolds averaged Navier-Stokes (RANS) simulation and large-eddy simulation (LES). This paper presents an STG for the multiple-relaxation-time lattice Boltzmann method (LBM) framework at high friction Reynolds numbers, with consideration of near-wall modeling. The Reichardt wall...

Ship anti-rolling devices are an essential component of modern vessels. The core component of the Magnus effect-based ship anti-rolling device is a rotating cylinder, hereinafter referred to as the Magnus cylinders. In this paper, fully parametric three-dimensional modeling of Magnus cylinders was performed, and the design space dimension was reduc...

The synthetic turbulence generator (STG) lies at the interface of the Reynolds averaged Navier-Stokes (RANS) simulation and large eddy simulation (LES). This paper presents a STG for the multiple-relaxation-time(MRT) lattice Boltzmann method(LBM) framework at high friction Reynolds numbers, with consideration of near wall modeling. The Reichardt wa...

The hubless rim-driven thruster (RDT) has become increasingly interesting for ship propulsion. Gap flow has been proven as the main feature of RDT that cannot be simply neglected. In this study, based on a classical hubless RDT, the effects of the gap geometry are studied by adjusting its axial passage length, and inlet and outlet oblique angles. T...

This study analyzes the amount of fatigue damage accumulated by polyester mooring lines in different wave parks for six heaving point absorber wave energy converters (WECs). The wave park simulation uses a coupled non-linear method that calculates the motion of the WECs and the mooring line forces simultaneously in the time domain. The amount of fa...

In this study, the performance of a pump-jet propulsor (PJP) with pre-swirl stator in open water is numerically investigated. Both full-scale and model-scale configurations are considered. The Reynolds-averaged Navier–Stokes equations and shear stress transport k-w turbulence model are used in the numerical calculation. The computational domain is...

In this study, unsteady low-frequency characteristics in a voluteless low-speed centrifugal fan operating at a high mass flow rate are studied with improved delayed detached eddy simulation (IDDES). This study is motivated by a recent finding that the non-uniformly distributed pressure inside this type of fan could be alleviated by improving the ga...

We study noise generation at the blade tips of propellers designed for future electric aircraft propulsion and, furthermore, analyze the interrelationship between noise mitigation and aerodynamics improvement in terms of propeller geometric designs. Classical propellers with three or six blades and a conceptual propeller with three joined dual-blad...

In this study, three voluteless centrifugal fans are compared for their aeroacoustic performances. The tonal noise is predicted by coupling the IDDES with Formulation 1A of Farassat. The sources of the tonal noise at the blade passing frequency (BPF) are identified. It is found that the sources are related to the fan inlet gap, which introduces hig...

The effects of elastic cavity walls on noise generation at transonic speed are investigated for the generic M219 cavity. The flow is simulated with the Spalart–Allmaras (SA) improved delayed detached-eddy simulation (IDDES) turbulence model in combination with a wall function. The structural analysis software uses a modal formulation. The first 50...

In this paper, the simulation and modeling of the turbulent atmospheric boundary layers (ABLs) in the presence of forests are studied using a lattice Boltzmann method with large eddy simulation, which was implemented in the open-source program GASCANS with the use of Graphic Processing Units (GPU). A method of modeling forests in the form of body f...

Throughout the years, a large number of research projects have been carried out to develop and evaluate different concepts for wind-assisted propulsion, which indicated optimistic fuel-saving rates. The propulsive performance of a single rigid windsail in the view of time-averaged properties has been analyzed in previous studies. However, the unste...

Wave energy has attracted increasing attention due to the transition to electricity generation of renewable energy sources. To achieve cost-efficient solutions for the commercial market of electricity generation, wave energy converters (WECs) must be deployed in wave energy farms. The array layout needs to be carefully designed, specifically for ea...

The use of wind-assisted ship propulsion is regarded as one of the effective ways to reduce greenhouse gas emissions. This study presents a numerical analysis of the aerodynamics of a single rigid wind sail using URANS (Unsteady Reynolds-Averaged Navier-Stokes equations). A new foil profile, the crescent-shaped foil, is proposed and then, compared...

The WaveEL wave energy converter (WEC) is a wave energy point absorber developed by Waves4Power AB. The newest generation, WaveEL 4.0, was recently proposed. With respect to the former 3.0 generation, the major updates are the length of the water tube beneath the buoy and the shape of the buoy. These geometric updates change the centre of gravity a...

In this paper, the gap effects on the aerodynamics and tonal noise generation of voluteless centrifugal fans are studied based on different gap geometries. The study is motivated by the state of the art of this type of fan, for which the tonal noise generation due to the gap turbulence has not been addressed concerning the gap geometry, while a rec...

The inflow distortion to the fan introduced by the ingestion of the fuselage boundary layer is the most critical challenge in realizing the benefits of boundary later ingesting (BLI) concepts. Minimizing the level of distortion while maintaining the desired amount of ingested boundary layer and free stream flow is crucial in minimizing the penaltie...

Forests play an important role in influencing the wind resource in atmospheric boundary layers and the fatigue life of wind turbines. Due to turbulence, a difficulty in the simulation of the forest effects is that flow statistical and fluctuating content should be accurately resolved using a turbulence-resolved CFD method, which requires a large am...

View Video Presentation: https://doi.org/10.2514/6.2022-3670.vid The effects of fluid viscosity and density on the aeroelasticity of the ONERA M6 wing over a wide range of free-stream Mach numbers, spanning 0.6–1.1, based on viscous and inviscid flow assumptions are studied. Both static and dynamic responses of the wing are examined. We employ a hy...

The development of the high-speed maglev train (HSMT) is important for the future of high-speed rail transit. A pressure wave (PW) is a common aerodynamic effect in high-speed railway tunnels. For HSMTs with a speed of 600 km/h, the amplitude of PW in the tunnel can be very big, which maybe far exceed the current design strength standard of the tra...

The paper presents a synthetic turbulence generator (STG) for the lattice Boltzmann method (LBM) at the interface of the Reynolds averaged Naiver-Stokes (RANS) equations and the LBM Large Eddy Simulation (LES). We first obtain the RANS velocity field from a finite volume solver at the interface. Then, we apply a numerical interpolation from the RAN...

The paper presents a synthetic turbulence generator (STG) for the lattice Boltzmann method (LBM) at the interface of the Reynolds averaged Naiver-Stokes (RANS) equations and the LBM Large Eddy Simulation (LES). We first obtain the RANS velocity field from a finite volume solver at the interface. Then, we apply a numerical interpolation from the RAN...

The paper presents a synthetic turbulence generator (STG) for the lattice Boltzmann method (LBM) at the interface of the Reynolds averaged Navier–Stokes (RANS) equations and the LBM large eddy simulation (LES). We first obtain the RANS velocity field from a finite volume solver at the interface. Then, we apply a numerical interpolation from the RAN...

Excellent seakeeping performance is the basis of safe ship operation. An anti-rolling device based on the Magnus effect [1] can provide anti-rolling measures at any ship speed. In this study, the operating principle of a Magnus anti-rolling device [2] was examined by studying its hydrodynamic performance using the large-eddy simulation method. The...

High-speed railway lines are widely distributed worldwide. The surrounding wind environment of such railway lines is complex, which significantly affects the safety of high-speed train operations. Using a combination of the computational fluid dynamics method of improved delayed detached eddy simulation and sliding grid technology, the effects of o...

The structural response of a dam to an earthquake event was modeled using three techniques: static structural analysis, one-and two-way coupled Fluid-Structure Interaction (FSI) modeling approaches. The aim was to investigate how the choice of method affects the peak total deformation, the principal stresses, and the maximum shear stresses within t...

The structural response of a dam to an earthquake with a dominant horizontal ground acceleration was modeled using three techniques: static structural analysis, one-and two-way coupled Fluid-Structure Interaction (FSI) modeling approaches. The aim was to investigate how the choice of method affects the peak total deformation, the principal stresses...

Volutes for radial-flow turbomachines (e.g., centrifugal fans and pumps) are spiral funnel-shaped casings that house rotors. Their function is to guide the flow from rotors to outlets and maintain constant flow speeds. Under specific conditions, however, volutes are removed (termed voluteless) to reduce flow losses and noise. In this paper, a gener...

In this study, noise generation is investigated for a generic voluteless centrifugal HVAC fan at an off-design operation point where tonal noise increases. The simulations are performed by coupling IDDES with the FW-H acoustic analogy, and the experiments are conducted in a rig consisting of a plenum chamber and a reverberation room. In contrast to...

In this study, an isolated centrifugal fan is investigated for the aerodynamic and acoustic performances usingRANS and URANS simulations. The noise is predicted by coupling the URANS and the Ffowcs Williams andHawkings acoustic analogy. The aerodynamic properties obtained from RANS and URANS are consistentwith the experimental data. The magnitudes...

A novel propeller with the blade tips joined in pairs, named Boxprop, is designed and optimized for a conceptual electric aircraft using an efficient optimization platform. According to the thrust requirement of the electric aircraft at cruise, the Boxprop with optimal efficiency is down-selected from the Pareto front of thrust coefficient and prop...

The adoption of ultra-high bypass ratio (UHBPR) engines has been long recognised to bring about reduction of specific fuel consumption and noise emission. In the need to fulfil ambitious environmental targets and mitigate the aviation sector impact, they represent a smoother technology change, compared to futuristic aircraft designs featuring elect...

In this study, tonal noise produced by an isolated centrifugal fan is investigated using unsteady Reynolds-averaged Navier-Stokes (URANS) equations. This type of fans is used in ventilation systems. As the fan propagates tonal noise in the system, it can severely affect the life quality of people that reside in the buildings. Our simulation shows t...

A new approach to predict the performance maps of automotive turbocharger compressors is presented. Firstly, a polynomial equation is applied to fit the experimental data of flow coefficient ratios for the centrifugal compressors with both vaneless and vaned diffusers. Based on this equation, the choke and surge flow coefficients under different ma...

The design of noise barriers for high-speed trains is challenging due to the flow interaction between the train body and barriers. A failed design could affect the flow that in turn introduces additional aerodynamic loads to the train and generates extra noise. This study is the first investigation to numerically explore the detailed effects of noi...

Supercritical Carbon Dioxide (SCO2) is considered as a potential working fluid in next generation power and energy systems. The SCO2 Brayton cycle is advantaged with higher cycle efficiency, smaller compression work, and more compact layout, as compared with traditional cycles. When the inlet total condition of the compressor approaches the critica...

A numerical study using IDDES is carried out to investigate the aerodynamic and the aeroacoustic response of a simplified ICE3 high-speed train model. The work focuses on the front part of the train and, in particular, on the first bogie cavity. The choice is justified by a literature survey which shows that this part of the train is the principal...

Flow-induced noise inside cab interior (also termed aerodynamics-induced interior noise) is nowadays perceived as a key factor when assessing the quality of heavy-duty vehicles. In order to satisfy the turnaround time required for current product development, a simplified hybrid numerical approach has been adopted. It couples the SNGR (Stochastic N...

Inside vehicle cabins, an important part of interior noise is generated from cabin window vibration. The vibration is stimulated by surface pressure fluctuations that are produced by exterior flows and flow-induced noise. To numerically investigate the cabin noise, both exterior flows and noise must be resolved in simulations. This requirement moti...

The dorsal root ganglion (DRG) that is embedded in the foramen of the cervical vertebra can be injured during a whiplash motion. A potential cause is that whilst the neck bends in the whiplash motion, the changes of spinal canal volume induce impulsive pressure transients in the venous blood outside the dura mater (DM) and in the cerebrospinal flui...

We investigate the interior noise caused by turbulent flows past a generic side-view mirror. A rectangular glass window is placed downstream of the mirror. The window vibration is excited by the surface pressure fluctuations and emits the interior noise in a cuboid cavity. The turbulent flows are simulated using a compressible large eddy simulation...