Assessing greenhouse gas (GHG) emissions produced from electric vehicles (EVs) and hydrogen vehicles (HVs) requires understanding of the carbon intensity of electricity generation. Without the decarbonisation of electricity generation, environmental benefits of low emission vehicles (LEVs) will be diminished. The UK aims to produce net zero emissions by phasing out and banning the sale of new conventionally

Abundant alcohols, including ethanol, propanol, butanol, and pentanol, are expected to be used in compression ignition engines to ease the shortages of fossil fuel. The various alcohols have quite a different combustion and emission characteristics in the engine due to the changes in molecular structures. In this paper, a series of experiments were conducted on a modified common-rail diesel engine

In this study, the effect of location, wettability, and thickness of the hydrophilic layer and also the effect of microporous layer (MPL) thickness on the dynamic water transport in the gas diffusion layer (GDL) of polymer electrolyte membrane fuel cell (PEMFC) is investigated using the Lattice Boltzmann method. The effect of the presence of hydrophilic layer and MPL on the number of dominant flow

The unsteady flow and fluid exciting force inside the multistage centrifugal pump were analyzed on the basis of large eddy simulation (LES). The reliability of the numerical simulation was verified by the experimental performance. The performance of pump calculated was closer to the experimental one than that by the Reynolds time average turbulence model, and the errors were 0.36% and 1.14% at the

Extended surfaces are widely investigated for their ability to enhance the heat transfer rates in different applications. Pin-fin and plate-fin heat sinks are used in a variety of cases involving a miniaturized to the large systems. The present study compares the performance of the pin-fin and the plate-fin heat sink under similar forced flow conditions. The experimental data for a modified pin fin

In a projectile, a turbopump is widely used to pressurize oxidizer and fuel to gain high thrust instead of using high pressure tank which has a disadvantage in total weight. Pumps in a turbopump employ an inducer upstream to prevent performance degradation by increasing pressure at the impeller inlet. However, cavitation and related instabilities take place frequently, so numerous analysis have been

Development of a gas turbine engine starts with optimization of the working process parameters. Turbine inlet temperature is among the most influential parameters that largely determine performance of an engine. As typical turbine inlet temperatures substantially exceed the point where metal turbine blades maintain reasonable thermal strength, proper modeling of the turbine cooling system becomes crucial

Pressure side (PS) cutback structure has been widely employed in modern turbine blade trailing edge (TE) cooling design. However, hot gas flows around lip of TE slot to generate an impingement to cutback, resulting in a rapid decay of film cooling effectiveness and hence thermal damage of entire TE. Proper angled-ejections upstream of TE can suppress the downstream effectiveness-decay. Therefore, in

Karman vortices forming behind blades or guide vanes may induce severe vibration and noise in hydraulic machinery. To solve these problems, the trailing edge of vanes or blades is usually trimmed as a remedy. However, this type of modification is not always effective. Based on an engineering project, two sides of the tail of an asymmetric guide vane were modified respectively. The influence of the

This paper presents a detailed and objective review of regenerative flow turbomachines, namely pumps, blowers and compressors. Several aspects of turbomachines like design and operating parameters, working principle, flow behaviour, performance parameters and analytical and Computational Fluid Dynamics (CFD) related details have been reviewed and summarized. Experimental work has been put in perspective

The sealing of the rotor-rotor gap and rotor disk cooling are vital to the safe operation of the vaneless counter-rotating turbine(VCRT). In order to quantifies the influence of the wheel-space cavity flow on the VCRT aerodynamic performance, and to improve turbine efficiency of the VCRT at certain rim seal ejection rates, numerical studies which considered the effects of rotor-rotor rim seal flow

The heat transfer performance of steam and air flow in a rough rectangular channel with different inverted V-shaped ribs was investigated by infrared thermal imaging technology. Under the conditions that the Reynolds number is in the range of 4000–15,000, the effects of the rib angle on the heat transfer enhancement of the two coolants were obtained. The rib pitch ratio of the flow channel is 10, the

Due to similarity to a previously published paper the following article has been retracted.

Heat leakage mechanisms need to be addressed in the thermal analysis of multi-stream heat exchangers due to their effects on the intended heat transfer between the streams. In this paper, multi-dimensional heat transfers between various fluid streams and also between the fluid and solid parts of a three-stream plate-fin heat exchanger is numerically modeled considering the variation of thermo-physical

This paper investigates the dynamic behavior of an Ultra-High Efficiency Gas Turbine Engine (UHEGT) with Stator Internal Combustion. The UHEGT-technology was introduced for the first time to the gas turbine design community at the Turbo Expo 2015. In developing the UHEGT-technology, the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed in

The tip winglet is employed to improve the flow stability of NASA Rotor 37. Two suction-side winglets with the maximum width of 0.25 and 0.5 times of the width of local blade tip section and two pressure-side winglets with the maximum width of 0.5 and 0.9 times of the width of local blade tip section are designed and evaluated by numerical analysis of 3-D flowfield. The results show a rough leakage

Assembled in series with multistage, Electrical Submersible Pumps (ESP) are widely used in offshore petroleum production due to the high production rate and efficiency. The hydraulic performance of ESPs is subjected to the fluid viscosity. High oil viscosity leads to the degradation of ESP boosting pressure compared to the catalog curves under water flow. In this paper, the influence of fluid viscosity

Here we simulate hydrodynamically and thermally fully developed carbon nano tubes, (CNTs) suspended nano fluid flow through annular sector duct. Hydrodynamic results are found by using no slip boundary condition on the solid walls of duct; whereas H1 and T thermally fully developed conditions are accounted to evaluate the thermal results. CNTs are considered to be single wall, (SW)/multi walls, (MW)

Increasing the gas temperature at the inlet to the high pressure turbine of gas turbine engines is known as a proven method to increase the efficiency of these engines. However, this will expose the blades’ surface to very high heat load and thermal damages. In the case of the un-shrouded turbine blades, the blade tip will be exposed to a significant thermal load due to the developed leakage flows

In order to explore the influence of low pressure on ignition process, the ignition performance of a linear combustor with five burners was experimentally investigated at ambient temperature and low pressure. At air pressure drops of 1%, 2% and 3%, the influence of low pressure on the lower boundary of the ignition equivalence ratio and ignition delay have been carried, and the high-speed camera was

The paper presents experimental data and results from a prediction tool for the performance of a desiccant loop cooling system. The experiments are performed under a variety of high humidity and hot ambient conditions and the system performance is described. One of the experimental conditions is typical of many Indian cities and the systems appropriate for those cities are established. A simulation

In this paper, to demonstrate the deposition effects on cooling performance, the changing patterns of film cooling due to particle deposition are numerically investigated on a turbine vane that is cooled by an array of film-holes. The uniqueness of this work is addressing the cooling performance at an early deposition stage, in which deposits are relatively slight. The build-ups of the deposits are

Production engine pass-off testing is a compulsory technique adopted to ensure that each engine meets the required performance criteria before entering into service. Gas turbine performance analysis greatly supports this process and substantial economic benefits can be achieved if an effective and efficient analysis is attained. This paper presents the use of an integrated method to enable engine health

The optimal performance of dew point indirect evaporative cooler with respect to the operational environment is a challenging task as the same is affected by many parameters. This paper reports the regression modeling and optimization of a counter flow indirect evaporative cooler using the response surface methodology. Experimentation is conducted using the central composite design and regression models

Present numerical investigation proposes to mitigate the effects of Counter rotating vortex pair (CRVP) by employing a pair of vortex generator. Numerical simulation has been carried out to investigate the effect of placement of vortex generator on the characteristics of film cooling effectiveness. Various configuration has been taken based on vortex generator location at upstream, downstream of circular

Low-temperature combustion (LTC) has advantages in reducing emissions and improving efficiency, at the expense of hard controllability. To improve its controllability, this paper proposes a two-stage stratified compression ignition (TSCI) strategy, which aims to decouple ignition and the following combustion as two-stage sequential high-temperature reactions, and couple them to external events like

Heat loss is a leading cause of heightened global temperatures and carbon dioxide. The energy crisis has raised concerns on addressing heat recovery, especially in iron and steel industries. Iron and steel industries are consuming roughly 10 to 15 percent of the world’s energy. Increasing the production of heat recovery can reduce carbon dioxide production, which in effect decreases the overall cost

In the present study, three types of w-wave trenches with different amplitude configurations are compared with transverse trench (TT), and the use of variable radius fillet (VRF) on downstream lips at different blowing ratio is numerically investigated to measure heat transfer coefficient, and cooling effectiveness. The numerical results are obtained by three-dimensional Reynolds average Navier–Stokes

The use of renewable energy as a future energy source is attracting considerable research interest globally. In particular, there is a significant growth in wind energy utilization during the last few years. This present study through a detailed and systematic literature survey assesses the wind energy potential of Kazakhstan for the first time. Using the Weibull distribution function and hourly wind

In order to keep wind turbines connected and in operation at all times despite the occurrence of some faults, advanced fault detection and accommodation schemes are required. To achieve this goal, this paper proposes to use the Linear Parameter Varying approach to design an Active Fault Tolerant Control for wind turbines. This Active Fault Tolerant Control is integrated with a Fault Detection and Isolation

Kerosene and diesel fuels involved in spray combustion operations are complex fuels composed of a wide and diverse variety of hydrocarbon components. For practical numerical modeling of the evaporation and combustion phenomena in a combustor, well-designed surrogates fuels that can mimic the real fuel thermal and chemical properties can be utilized. In this study, predictions and validations of the

In this paper, a hexagonal prism inlet chamber is used to form a swirling flow for the film cooling, and three kinds of compound angle of film hole (γ = 10°, 20°, 30°) with clockwise swirling or counterclockwise swirling are used for numerical simulation studies. The influence of different compound angles of film hole and the swirling directions for the film cooling effectiveness are obtained. The

The modern power generation system requires steam turbines operating at flexible operating points, and flow instabilities readily occur in the low-pressure (LP) last stage under low-load conditions, which may cause failure of the last stage moving blades. Some studies have shown that within this operating range, a shift of the operating point may lead to flow instabilities. Numerical simulation has

Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. The purpose of turbocharging is to increase the engine inlet air density by utilising, the otherwise wasted energy in the exhaust gas. This energy extraction is commonly accomplished through the use of a radial turbine. Although less commonly used, mixed flow turbines

We present a unique comparison of two types of renewable hydro pumping devices, namely the ram and turbine pump having different working principles. This comparison is based on experiments with these pumping devices at a field station in a village in central-east India. Our work identifies the major gaps in the study of large ram pumps, covering the hydraulic scaling conformance to creation of a unified

This study proposes a 1D meanline program for the modeling of modern transonic axial multistage compressors. In this method, an improved blockage factor model is proposed. Work-done factor that varies with the compressor performance conditions is added in this program, and at the same time a notional blockage factor is kept. The coefficient of deviation angle model is tuned according to experimental

In order to suppress the tip leakage loss and increase the isentropic efficiency in a radial turbine with low aspect ratio blade, a new coupling flow control technology including casing groove and NACA blade profile is proposed and optimized numerically. The coupling effects of casing groove size LS, groove number Numslot, maximum thickness location of profile MLT and leading parameter of profile LP

Main reason of compressor instability is boundary layer separation on the surface of blades. As one of flow control methods of the compressor, slotted blade has attracted many researchers’ attention because of its simple geometric structure and remarkable flow control effect. In order to evaluate its availability in the compressor, a type of convergent slot is designed to implement in a single-stage

It is well known that the Łagisza power plant in Poland is the world’s first supercritical circulating fluidized bed (CFB) boiler, whose commercial operation started on June 2009. It has attracted a great deal of interest and operational data are publicly available, therefore it has been chosen as the object of the present study aimed at assessing load and fuel flexibility of supercritical CFB plants

Cross-flow fans are widely used in heating, wind-curtains, and air-conditionings, as well as other ventilation systems. A single or double arc is generally used as the camber line of cross-flow fans, but this design leads to constraints in the geometry of the blade profiles. In this study, the camber line of a cross-flow fan blade was parameterized by five parameters based on the fourth-order Bezier

In this study, the atomization of heavy fuel oil (Mazut) and diesel fuel at different pressures is compared experimentally. Also, the effects of temperature on the Mazut fuel atomization are investigated experimentally. Mass flow rate, discharge coefficient, wavelength, liquid film thickness, ligament diameter, spray angle, breakup length, and sature mean diameter are obtained for the Mazut and diesel

The recent changes in energy scenario with rising attention to decarbonization, introduction of new technology and renewable source have led to design power plant with the lowest values of cost of energy, investment payback period, CO2 emission, especially in cogeneration and combined cycle plants. The cost of a gas turbine, an industrial key intellectual property value, represents a large portion

The unsteady characteristic in the tip region of an axial compressor has been numerically studied with the help of the dynamic mode decomposition analysis. The characteristics of frequency and dynamic modes are compared and discussed under different operating points and different parameters, such as tip clearance and rotating speeds. For the flowfield structures in the tip region, such as tip leakage

Unlike fixed-base offshore wind turbine, the soft floating platform introduces 6 more degrees of freedom of motions to the floating offshore wind turbine. This may cause much more complex inflow environment to the wind turbine rotors compared with fixed-base wind turbine. The wind seen locally on the blade changes due to the motions of the floating wind turbine platform which has a direct impact on

A clear understanding of the flow characteristics in the older generation of industrial gas turbines operating with silo combustors is important for potential upgrades. Non-uniformities in the form of circumferential and radial variations in internal flow properties can have a significant impact on the gas turbine stage performance and durability. This paper presents a comprehensive study of the underlying

This paper presents an in-depth investigation of the unsteady flows through two-stage high-pressure (hp) axial turbine with analyses of the rotor-stator interaction effects on the aerothermodynamic performance. The unsteady flow structures are characterized by the formation and convection of the tip leakage vortex and the hub corner vortices from the first stage blade-row through the second stage nozzle

To investigate the influence of tip winglets on the tip leakage flow in a compressor cascade with different incidences, the experimental measurement combined with numerical simulation are used to study the conventional cascade and cascades with three different pressure surface tip winglets at five incidences of −6°, −3°, 0°, +3° and +6°. The results indicate that three different tip winglets at five

With the aim to analyze the flow pattern and heat transfer characteristics of the working fluid in a flat plate heat pipe (FPHP) which was sealed by a transparent tempered glass plate, ethanol, acetone, and R141b were taken as the working medium, and visual experiments were performed at different heat flux when the inclination angle was 90°. The vapor-liquid distribution and the heat transfer characteristics

Effects of the staggered blades on unsteady pressure pulsations of a centrifugal pump with a specific speed ns=147 are investigated by the numerical simulation method. The obtained results are compared with the original blades. To clarify the resulting effects, eight monitoring points are used to extract pressure signals at three typical working conditions, and component at the blade passing frequency

A thermopile, in which a number of thermocouple junctions are arranged on either side of a thin layer of insulation, is commonly used to determine the heat flux for steady-state measurements. Gauges using this method are available commercially and a new, generic calibration method is described here. For this purpose, an equation based on physical properties has been derived to determine the theoretical

Performance of varying speed screw chiller is affected by many uncertainties. High precision prediction of its characteristics can guide the chiller to reach a better performance. This study presents an artificial intelligence model named least square support vector machine (LSSVM) with genetic algorithm (GA). Five parameters are predicted with the model, including COP, discharge pressure, suction

Three-dimensional CFD simulations are carried out to study the increase of power generated from Savonius vertical axis wind turbines by modifying the blade shape and blade angel of twist. Twisting angle of the classical blade are varied and several proposed novel blade shapes are introduced to enhance the performance of the wind turbine. CFD simulations have been performed using sliding mesh technique

Experimental and numerical analysis is arranged with exergy destruction to evaluate thermal performance of system on nanofluid flow in tube with single and double strip helical screw inserts at different values of twist ratio in laminar flow regime. CFD analysis has occurred on the fluent workbench of ANSYS software. The Nusselt number attained enhancement with the flow of nanofluid in double strip

In order to deeply analyze the application prospect of the boundary layer suction technique on the compressor, the flow control effect of endwall suction scheme on the tip leakage flow of a compressor cascade at a large incidence angle with complex internal flow structure and different loss proportion from the case at design incidence angle, was studied numerically, as well as on the overall aerodynamic

The strut structure directly affects the flow field characteristics and aerodynamic performance of the gas turbine exhaust diffuser. The effects of the strut profiles and strut skewed angles on the aerodynamic performance of the exhaust diffuser at different inlet pre-swirls were numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes(RANS) and Realizable k-ε turbulence model

The development of flow control methods in the centrifugal pump relies on further understanding of the characteristics of vortex structures and their irreversible losses. In this paper, the detached eddy simulation is conducted on a model centrifugal pump, which shows a good agreement with the experiment. Combining with three generations of vortex identification methods (vorticity, Q criterion, omega

Cavitation damage in engine cooling water pump is the main factor that shortens the lifespan of the cooling system and gives rise to undesirable phenomena such as vibration and noise. In order to reveal the influence of key factors such as temperature and speed on the cavitation performance of engine cooling water pump, the cavitation performance of the engine cooling water pump under different rotating

Tandem configuration is an effective methodology to reduce flow separation on compressor blade suction surface and to improve blade loading. However, in modern highly loaded cases, corner separation remains as its single blade counterpart. In this study, non-axisymmetric endwall profiling (NAEP) was utilized in a highly loaded tandem cascade (diffusion factor D = 0.69), aiming at reducing its severe

Wind energy is a widely used and developed the renewable energy, which has developed rapidly. At present, the design of the horizontal axis wind turbine blade mainly used Blade Element Momentum theory. In this paper, an optimization method of the wind turbine blade was proposed for improving the output power. The local twist angles of the blade were optimized. This method combined the surrogate model

In this paper, the performance of the turbine blade squealer tip has been studied detailed aimed to highlight the impact of the upstream guide vane passing wake. The first stage of GE-E3 high-pressure turbine has been employed to perform the three-dimensional simulation and the computational domain has been scaled based on the domain scaling method. Boundary conditions are consistent with operating