A system of a spiral plate heat exchanger and its required auxiliaries was built. The pitches of heat exchanger were built differently to provide almost two geometrically different heat exchangers in a single package. Several experiments were done and working parameters of the heat exchanger were measured. A code was written to find a new optimised correlation that could approximate the Nusselt Number

In the Ultra-High Efficiency Gas Turbine Engine, UHEGT (introduced in our previous studies) the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed within the axial gaps before each stator row. This technology substantially increases the thermal efficiency of the engine cycle to above 45%, increases power output, and reduces turbine inlet temperature

In this paper, OpenFOAM wave generation and active wave absorption boundary conditions were used to simulate wave interaction of a specific experimental wave energy converter (WEC) with equilibrium buoys and two power take-off systems that work in parallel, over a broad range of wave conditions. Two solitary and cnoidal wave generation boundary conditions for three different wave heights were implemented

In this study, the condensation heat transfer coefficient and pressure drop of steam are obtained in small rectangular tubes with different aspect ratios. The experiments were carried out on three rectangular tubes with aspect ratios of 1:2, 1:3 and 1:5, with mass flux between 25 and 45 kg/m2s, and vapor qualities between 0.1 and 0.8. The experimental data were analyzed to determine the effect of vapor

This numerical study aims at predicting the reflective behavior of different conventional inlet and outlet far-field boundary conditions as well as available non-reflecting boundary conditions (NRBC) implemented in the commercial CFD solver ANSYS CFX. An isolated rotor model of an axial turbine stage with prescribed blade displacement is applied as test case to consider a representative application

A computational method of fluid-structure coupling is implemented to predict the fatigue response of a high-pressure turbine blade. Two coupling levels, herein referred to as a “fully coupled” and “decoupled” methods are implemented to investigate the influence of multi-physics interaction on the 3 D stress state and fatigue response of a turbine blade. In the fully-coupled approach, the solutions

The exhaust energy recovery is significant for engine fuel efficiency. However, the exhaust gas interference and the loss of flow affect the utilization of exhaust energy of multi cylinder turbocharged diesel engine seriously. In this paper, through Particle Image Velocimetry experiment and computational fluid dynamics simulation of exhaust T-junction flow field, the characteristics of junction local

The low-pressure steam requirement in the iron and steel production plant is obtained through pressure reduction stations with unrestrained expansion. In this study, the feasibility of obtaining the low-pressure steam that is needed in the plant in a backpressure turbine instead of pressure reduction stations has been studied. In this way, it is foreseen that a significant amount of wasted energy during

Hydraulic ram pump is an automatic water-lifting machinery, which converts the low-head potential energy of a large volume of water into a small high-head potential energy through the periodic open and close of waste valve and delivery valve. The pump would run inefficiently or even fail if the valves are poorly designed. In this paper, a novel and reliable waste valve of lift-check-valve structure

The clocking position of the vaned diffuser, the circumferential position of the vaned diffuser relative to the volute, has a certain effect on the performance of the centrifugal pump. Therefore, this paper studies the guide vane centrifugal pump from the aspects of pressure pulsation, hydraulic performance, and energy loss. The maximum difference in efficiency is 3.4% under the design flow rate, and

In this paper, influences of structure parameters on mass flow and atomization characteristics (spray cone angle, SMD, liquid film fusion and separation) of dual-orifice atomizers were investigated using Fraunhofer diffraction optical instrument and high-speed shadowgraph technique. The main influential structure parameters are obtained by structural parameter sensitivity analysis. Liquid film fusion

The cooling of radiators in power transformers employing natural oil-air forced method is the purpose of this study. Two modes used for cooling fans, namely vertical and horizontal placement, will be compared as well. Four sets of radiators have been studied in this research, and in each set, 14 fins and three fans with a diameter of half a meter have been used. The fans will be arranged such that

In the present study numerical simulation of flow boiling process has been conducted for evaluation of critical heat flux conditions under the effect of different parameters (mass flux, heat flux, channel length and surface roughness). Comparison between the results of the present study and previous researches were done. The comparison shows a good agreement between the present study and previous researches

This paper investigates the influence of different tip clearances on the transient characteristics of mixed-flow pump under stall condition. The instantaneous internal flow fields of mixed-flow pump with four tip clearances (0.2 mm, 0.5 mm, 0.8 mm and 1.1 mm) are explored by conducting unsteady time accurate simulations. Reynolds-averaged Navier-Stokes (RANS) equations are employed in the simulations

In turbmachinery, splitters are used to control secondary flow and to improve the aerodynamic performance of outlet guide vane (OGV) of axial fan. However, there is few information in the open literature focusing on the effect of the splitter geometry on the secondary flow control. In this work, the numerical investigations were performed for NACA 65-010 profile with different splitters. The spacing

Natural draft dry cooling towers (NDDCTs) serve a fundamental role in the deployment of concentrating solar power (CSP) plants. In a multi-tower cooling system, there is a need to be able to position them correctly so that their performance as a group is maximised. To do this, an understanding of the effect they have on one another is needed. Hence, this work investigated the effect of tower spacing

In this paper, the optimization method we obtained from dual-orifice atomizers previously is used to design and optimize new dual-orifice atomizers, whereas there are some differences between the new dual-orifice atomizer and dual-orifice atomizer used in Part I. For example, the mass flow is much smaller, there is an expansion angle at pilot nozzle to regulate pilot stage spray cone angle, and there

This work targets the development of the multidisciplinary design for centrifugal fans, based on the calculation of the fan performance following changes in the fan structure and manufacture. A parametric method that starts from the blade number and manufacturing parameters is first developed to control the shape of fan assembly and its fluid domain. The parametric code, and the aerodynamic and structure

The inlet flow conditions will directly affect impeller performance, which is of great concern to pump designers. In this study, based on two axial-flow pump devices, the influence of the evaluation criteria of inlet flow conditions and numerical grid scales on the accuracy of the simulation are investigated, the correctness of the numerical simulation are verified by experiments. The axial velocity

To extend the current understanding of the circumferential groove casing suction applied to a counter-rotating axial flow compressor, the impact of different axial locations of the circumferential suction groove on the characteristics of the tip leakage flow (TLF) and the corresponding physical mechanisms producing the stability enhancement have been studied based on validated numerical simulations

A lobed swirl injector was tested to examine its potential in combustion control for non-premixed and partially premixed flames. It was found in the experiment that the flame derived from the injector changed between attached and detached flames at different conditions, demonstrating a promising way to control combustion. When air is supplied through the external channel of the lobed swirl injector

This study investigates the effects of inlet guide vane (IGV) and blade pitch angles on the steady and unsteady performance of a submersible axial-flow pump. To analyze the interaction between the IGVs and the rotor blades, both steady and unsteady three-dimensional Reynolds-averaged Navier-Stokes equations were used with shear stress transport turbulence closure. Hexahedral meshes were used in the

The Ultra-High Efficiency Gas Turbine Engine (UHEGT) was introduced in our previous studies. In UHEGT, the combustion process is no longer contained in isolation between the compressor and turbine. It is rather distributed in multiple stages and integrated within the high-pressure turbine stator rows. Compared to the current most advanced conventional gas turbines, UHEGT considerably improves the efficiency

The performance of a heat pipe is governed by many parameters, the effects of which may influence each other. Hence, it is utmost important to optimize the combination of these parameters for an effective energy transfer in a heat pipe. In the present study, the interacting effects of four different parameters affecting the effectiveness of heat pipe are studied namely the fluid filling ratio (20%

For the intermittent nature of renewable resources (such as wind and solar), smooth power fluctuations are required before the energy conversion system can be injected into the grid. The battery system is a typical smoothing control method for photovoltaic power. The long-term overcharge and overdischarge make the battery energy storage scheme unattractive. In this paper, the output power fluctuation

The shrouded radial-inflow turbine is widely employed as a power generation device in the compressed air energy storage (CAES) system. The loss mechanism and off-designed performance of the shrouded radial turbine are lesser known hitherto and should be deeply understood. Loss analyses of a shrouded radial turbine are conducted numerically based on the first and second laws of thermodynamics in the

The work presents a data driven based strategy to develop a new statistical model of complex tip shape for high-pressure turbine stages exploiting an existing dataset of optimized squealer-like rotor tips. Using the exploratory data analysis (EDA), a set of statistical methods were used to improve the quality of previous CFD-based optimization dataset, as an aid in reducing outliers, data skewness

In this paper, a numerical investigation was conducted into the impact of the tip clearance height and the relative motion between the casing and the strake wall tip on the tip clearance leakage flow of a supersonic expander. Besides, an analysis was carried out to characterize the flow under varying operating conditions. Numerical results show that the remarkable characteristics of motion within the

Co-combustion characteristics of wheat straw with polyvinyl chloride under different oxygen concentration atmospheres were investigated using a thermogravimetric analyzer. Experimental samples included wheat straw, polyvinyl chloride, and their blends. The results showed that when the wheat straw was blended with polyvinyl chloride, there was an inhibition for devolatilization in the volatile combustion

Air injection is an effectively methodology to suppress flow separation and to improve blade loading of airfoils and compressors. In order to remove corner separations in a cascade, investigation of endwall slotted injection was carried out numerically in this study. Based on endwall slot schemes of other flow control methods, six different endwall slots were designed, aiming at revealing the axial

The flow in centrifugal compressors is viscous and unsteady. Flow separation off the blades challenges the accuracy of simulations. A viscous body force model is expected to speed up numerical convergence and reduce the computational costs of unsteady simulations. In this paper, both stability and accuracy of the viscous body force model are investigated based on the case of a low-speed centrifugal

To investigate the effect of tip clearance on the velocity distribution in a multiphase pump, the internal flow and velocity distribution characteristics in pump under different tip clearances are studied using experimental and numerical methods. Simulations based on the Reynolds-Averaged Navier-Stokes equations (RANS) and the standard k-ε turbulence model are carried out using ANSYS CFX. Under conditions

As more battery electric vehicles and plug-in hybrid electric vehicles are connected to the microgrid, plug-in electric vehicles have a major impact on the microgrid. This paper proposes a multi-objective optimization energy management model including plug-in electric vehicles and other distributed generations. By analyzing the powertrain structure of different kinds of plug-in electric vehicles, the

Secondary flow injection is a way which allows for the efficiency of a turbomachine to be increased further, after blade design optimizations have already been performed. In this paper, a novel method for improving turbine performance using secondary flow injection through an injection slot over the turbine shroud is investigated. Numerical simulations were conducted on a mixed-flow turbocharger turbine

An experimental study on gas–liquid two-phase flow characteristics in a low-specific-speed centrifugal pump is presented via employing multiple investigation techniques, such as visualization observation, measurements of acoustic emission and vibration, etc. Specially, three different flow conditions were inspected, namely gas locking initiation, critical cavitation with/without free-gas presence,

Cavitation is of significant practical interest due to its unsteady features which could induce destructive effects such as drastic drop in efficiency, noise, vibration, and corrosion for propulsion systems, rudders and other hydraulic machinery. A thorough understanding of the hydrodynamics in the cavitating flow past a three-dimensional hydrofoil makes indicators for an improved control performance

Quasi-labyrinth seal technique was innovatively adopted to control the slashface flow, and the effect of slashface leakage on endwall aerothermal performance and blade suction side surface phantom cooling was numerically investigated. Simulations of five different labyrinth seal lengths (Ls) and three coolant momentum flux ratios (I) were conducted by computationally solving the Reynolds-averaged Navier–Stokes

Kütahya is considered as a candidate region for a wind farm investment due to Turkey's 2023 energy targets and its proximity to other wind farm investments. In this study, two years of wind data collected from a hill near the Evliya Çelebi Campus of Kütahya Dumlupınar University was used to evaluate the wind farm potential of Kütahya. First, the wind speed, wind direction, wind shear, turbulence intensity

A probabilistic method for modelling empirical site-specific wind turbine power curves is proposed in this paper. The method is based on the Gaussian mixture model machine learning algorithm. Unlike standard wind turbine power curve models, it has a user-selectable number (N) and type of input features. The user can thus develop and test models with a combination of measured, derived or predicted input

In this paper, a two-dimensional model has been developed to simulate the liquid water transport in a cathode gas diffusion layer with different porosity gradients in polymer electrolyte membrane fuel cells (PEMFCs). Due to the complexity of porous media, the simulation was carried out by lattice Boltzmann method. According to dimensionless numbers that characterize liquid water transport in porous

Jeju Island has implemented “Carbon-Free Island, Jeju by 2030” plan since 2012. The main means to realize it to be a carbon-free region is penetration of electric vehicles and renewable energies. In this paper, we summarized status and characteristics of Jeju Island’s wind power generation and confirmed change of wind resource in the island according to climate change. The yearly averaged wind speed

Wind turbines are of the most promising devices to cut down carbon emissions. However, some phenomena that adversely affect their performance are inevitable. The aim of the present paper is to investigate flow separation prevention exploiting leading edge (LE) single dielectric barrier discharge plasma actuator (SDBD-PA) on an airfoil belonging to a section of a locally developed wind turbine. The

With the transition to more use of renewable forms of energy in Europe, grid instability that is linked to the intermittency in power generation is a concern, and thus, the fast response of on-demand power systems like gas turbines has become more important. This study focuses on the injection of compressed air to facilitate the improvement in the ramp-up rate of a heavy-duty gas turbine. The steady-state

The study involves a bottom-up approach, from bottom cells to large supercapacitor pouch cells, encompassing the design, modelling and fabrication stages of the cells leading to a 12 V transient start–stop (TSS) power system for automotive applications. More specifically, the design of a large composite supercapacitor is presented, consisting of a high power density component and a high energy density

The effect of the axial gap on the energy consumption of a single-blade wastewater pump (Sulzer XFP PE-2 150E CB1.1) is assessed using unsteady Reynolds-averaged Navier–Stokes simulations with ANSYS Fluent. The numerical model was compared to experimental data with a nominal design configuration (i.e. gap size) to provide confidence in the modeling approach. The global performance of the pump was evaluated

Cavitation phenomenon is inevitable in pumps with strong transient characteristics. Due to the presence of vapors, the pressure distribution in the impeller changes greatly, resulting in a different radial force distribution from that in non-cavitation condition. In the present article, the cavitation performance of double-suction pumps with different impeller–vane arrangements is studied using the

The fluid flow and thermal characteristics of the dual jet are explored numerically. The dual jet is considered with a wavy wall surface having various amplitudes varying between 0.1 and 0.7 with a fixed number of cycles equal to 10. The offset ratio is also varied from 3 to 15 with an interval of 2. The Reynolds number and Prandtl number are set to 15,000 and 0.71, respectively. The Semi Implicit

Many new turbine designs may take large timelines to prove their worth. For getting duty condition at optimum efficiency, one can always scale speed, diameter, if a very efficient benchmark is available. This paper examines the similarity-based scaling strategy to develop radial inflow turbines for different compressible fluids from a well-established NASA radial flow turbine designed and experimentally

Boundary-layer-ingesting fans and compressors in the next-generation turbofan engines require high-performance operations under distorted inflow. The aim of this work is to study the effects of inlet distortions including inlet stagnation pressure and temperature distortion, on the aerodynamic performance of a transonic axial fan. Firstly, the validated full-annulus, unsteady, three-dimensional computational

In this article, a preliminary design framework containing a detailed design methodology is developed for modern low emissions aero combustors. The inter-related design elements involving flow distribution, combustor sizing, heat transfer and cooling, emission and performance are coupled in the design process. The physics-based and numerical methods are provided in detail, in addition to empirical

The current study numerically investigates the flow instability under several part-load conditions in a centrifugal pump with a straight inlet pipe to explore the underlying relationship between a positive slope phenomenon and internal flow using a partially averaged Navier–Stokes model. The model was validated by comparing the hydraulic performance and averaged flow in the impeller between the numerical

A hybrid lean blow-off prediction method based on Damköhler (Da) number was proposed in the authors’ previous study. However, the uniform model for fuel drop size distribution cannot fully reflect the actual atomization quality under lean blow-off conditions, which has negative effects on prediction accuracy. In the current study, atomization experiments are conducted under different fuel supply pressure

Automotive electronic cooling pump is the core component of the new energy vehicle cooling system, with the exclusive advantages of high efficiency and low vibration which will bring a broad market prospect. However, the rotor–volute interaction between impeller blades and volute tongue is a severe problem which can result in the performance degradation and unsteady flow fields of pumps. The influences

Most recently, an ascending tendency in nanoparticles containing working fluid utilization has been observed in such thermal systems as double pipe heat exchangers and thermosiphons in so far as its advantages upon the performance of such systems. In order to investigate how the type of the base fluid affects the nanofluid’s properties used for thermal applications, an experimental test rig was setup

This article presents the lift and drag coefficients of cambered plate blade sections of different relative camber at moderate Reynolds numbers. Relative cambers between 0% and 8% are investigated at an angle of attack range from 0° to 10°. Based on own measurements and literature data, empirical formulae are proposed for the determination of the lift and drag coefficients for Reynolds numbers within

In order to evaluate the potential of stall recovery at different operating points during the stall process in a transonic environment, three-dimensional multi-passage numerical simulations were conducted on the transonic compressor, NASA Rotor 37. The results showed that the whole stall evolution process can be divided into three stages depending upon the possibility for the compressor to recover

In this research work, a computational modeling of multi-phase flow through an asymmetric exhaust hood is presented. The three-dimensional Navier–Stokes equations along with the standard k-ɛ turbulent model and the Eulerian–Eulerian multi-phase equations were solved. The coupling of the last stage turbine blades and the exhaust hood has been carried out using the actuator disc model, which is less

A dynamic simulation of a modern ultra-supercritical circulating fluidized bed (USC-CFB) boiler system was performed using a physics-based model, where the boiler system was composed of an integrated system of heat exchanger (HEX) blocks. In each of the discretized elements of the HEX blocks, supercritical steam flow interacted with the solid–gas flow via heat transfer, and conservation laws, and physical

This paper presents a method to significantly accelerate optimization of film cooling systems. The method combines high-fidelity computational fluid dynamics with scalar tracking implemented, a proxy model (linear superposition model) initialized with the computational fluid dynamics solution, and a multi-objective evolutionary algorithm approach. The proposed method is structured as follows: the computational

Nearly all energy generated eventually ends as a thermal release to atmosphere. The combination of all these sources of heat is warming the planet amid concerns over the consequences of this global warming. Most fuels are hydrocarbons and on combustion release carbon dioxide. This is a greenhouse gas and amplifies the effects of this warming, as does methane, a major constituent of natural gas, the