bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shock wave Boundary Layer Interaction (SWBLI) in hypersonic flow over a Blunt body double wedge configuration
Authors: Meshram S , Siva Vayala , Peetala R K 
Published: August 2019

Abstract
Present investigations are focused on the study of effects of dimensional and parametric changes in shock wave boundary layer interaction (SWBLI) for an axisymmetric double wedge with leading edge bluntness in hypersonic flows. This study is specifically the point of interest since it attributes most of the characteristics of the hypersonic flow around the atmosphere re-entry vehicles. Successfully implemented simulations in hypersonic flow are in a double wedge configuration, to study shock wave boundary layer interaction in hypersonic flows. Inversion radius was found at different deflection angles for change in leading edge radius (LER). It was found that for lower deflection angle Crocco’s theorem affect the flow early compared to higher deflection angles. Shock-shock Interaction-I (SSI I) and Shock-shock Interaction-II (SSI II) shifts downstream with increase in leading edge radius. (Key Words: Hypersonic flows, Shock wave boundary layer interaction, Shock–shock interaction and Leading edge radius)
CFD Analysis of flow around fish
Authors: Palit Swastika , Sinha Shreya , Aylmer Britto R , Arockia Selvakumar A 
Published: August 2019

Abstract
The study of fish like bodies in the liquid is a challenging research area in the fields of bio-locomotion and biomimetics. The power and maneuvering of swimming fish will help a lot in the field of underwater vehicles. Mainly the effect of tail oscillation and abdomen oscillation on fluid flow around such a body is highly unsteady, generating vortices and requiring detailed analysis of fluid-structure interactions. In the present context, a computational fluid dynamic (CFD) simulation of a tilapia fish has been developed to study about the fluid flows around this body when moving in water using the k-epsilon turbulence model. A parametric analysis of the variables that affect the flow surrounding the body is presented, along with flow visualizations. In the present study, a detailed unsteady and transient CFD analysis of the effect of tail and abdomen oscillation on the fluid flow around the fish has been studied. The simulation produces a motion of the tail and abdomen in the (x, y) plane, with both the tail and abdomen oscillating in the form of a sinusoidal wave. Detailed CFD analysis is done and results in terms of the aerodynamic force coefficients namely the lift and drag coefficients, pressure contour and velocity contour have been presented and discussed for the linear motion of fish along z-axis along with periodic oscillations of tail and abdomen in the (x,y) plane. It was observed that both the aerodynamic coefficients and forces came out to be very less which paves way for the motion of the fish with high efficiency. The analysis provided by the simulations has allowed the flow surrounding the tilapia fish undergoing periodic oscillations along with a linear motion to be studied in detail.
Numerical analysis of drag and lift coefficient of a Sport Utility Vehicle (SUV)
Authors: Samy G S , Thirumalai Kumaran S , Uthayakumar M , Sivasubramanian M , Bhagavathi Sankar Krishna 
Published: August 2019

Abstract
The paper describes the modeling and analysis of a Sport Utility Vehicle (SUV). The present study mainly focuses on the reduction of aerodynamics drag and lift coefficient of a car, which helps to improve the vehicle performance and fuel efficiency. Usually the aerodynamic drag and lift is insignificant at low vehicle speed but the magnitude of air resistance becomes considerable with accelerating the vehicle. The Computational Fluid Dynamics (CFD) helps to analyze the flow stream around a SUV. The modeling software is used to design a 3D car model and the flow stream is analyzed by ANSYS Fluent. Initially, the first model was analyzed at various velocity conditions using Reynolds-Averaged Navier–Stokes (RANS) with standard k-ε model. The basic model of SUV has a drag coefficient and lift coefficient value of 0.62 and 0.099 respectively. Initially the first model is designed by introducing air splitter on roof and based on the results the second model is designed by introducing 15 degree boat tailing angle with first model. The drag reduction is reduced by 6.45% for first model and 19.35% for second model compared to the base model. Similarly, the lift coefficient is reduced by 2.02% for first model and 30.30% for the second model. Moreover the second model produces low drag and lift coefficient than first and base model. A significant reduction is observed in first model when compared to the base model. The vector plots are used to examine the streamline path of both the models.
Performance evaluation of a bulb turbine designed for ultra-low head applications
Authors: Shandilya Sonal , Shelar Sujit P. , Prasad Das Shyama , Chatterjee Dhiman , Saini R. P. 
Published: August 2019

Abstract
Hydropower is one of the most common forms of clean source of electricity and forms an important source of power for a country like India. This paper is aimed to design mini-hydropower which utilizes ultra-low head and can be used for decentralized power generation and utilization for remote villages. In order to achieve this purpose an axial flow turbine without any guide vanes is designed. This design process is adopted because the presence of inlet guide vanes in the conventional bulb turbines may pose maintenance problem of clogging and also the design is not fish friendly. Another aspect of micro- or mini-hydropower is the non-availability of large reservoirs and there is likelihood that these turbines may be installed as a run-of-the-river type with some seasonal variation of flow rate. The turbine efficiency should be as much as insensitive to the variation in flow rate as possible. In our work, the turbine is expected to produce a relatively flat efficiency flow rate-curve over a range of flow rates. The peak efficiency obtained is about 74%. There is a need to improve the peak efficiency and hence loss analysis is carried out. It was found that the swirling flow in the draft tube downstream of the turbine contributes to a monotonic increase in loss with an increase in flow rate.
Solidification in Stratified Flow of Two Immiscible Fluids in a Double-Bend
Authors: Hongying Li , Goharzadeh Afshin , Jing Lou , Yit Fatt Yap 
Published: August 2019

Abstract
This article presents an investigation of solidification in stratified flow of two immiscible fluids in a double-bend. A combined enthalpy-level-set approach for solidification is employed. The fluid-solid and fluid-fluid interfaces are captured respectively using the enthalpy and the level-set methods. The approach is verified against the scenario of a thick water layer sandwiched between a wall and an oil layer with water solidifies on the wall where semi-analytical solution exists. With the approach verified established, the effects of Reynolds number, Stefan number, viscosity ratio, thermal diffusivity ratios on flow and heat transfer are investigated.
Study of Interference Effects on Chimneys
Authors: Shruti K , Rajesh Sreeram , Sabareesh GR , Rao PN 
Published: August 2019

Abstract
Fluid flow studies play a vital role in proper assessing of wind loadson buildings and other civil engineering structures with various shapes. The presence of adjacent structure may alter wind loads on the structure of interest, by altering the fluid dynamics surrounding the structure. This effect is termed as interference effect and it depends on various factors such as terrain category, wind angle, geometry & orientation of the structure, spacing between the structures etc. Thus, proper assessment of interference effect with above factors, can lead to efficient design of structures that can withstand the load variations due to the presence of interfering structures. The existing literature on wind interference effects, focuses more on experimental analysis of the problem, which is both expensive and time consuming. In this regard, computational fluid dynamics (CFD) approach can serve as a quicker and efficient tool. In an attempt to study the effect of geometry &orientation of structures on interference phenomenon, turbulent flows around the buildings, cooling towers and chimneys have been simulated through CFD approach by performing Large Eddy Simulation (LES). In the present study, interference factors of a typical chimney structure has been evaluated by considering the presence of an identical chimney at varying distances, under different wind angles.
Numerical simulation of water droplet impact test on aircraft wing structure
Authors: Manigandan S. , Dineshkumar  , Ramanathan Muthiaya , Gunasekar P. , Devipriya J. , Nithya S. , Gokulnath R. 
Published: August 2019

Abstract
The three-dimensional simulation is carried out to study the collision dynamics of the water droplets impinging on the aircraft structures at higher velocities. The composite wing made of hybrid fiber of combination, Kevlar-Glass with nanocomposite graphene (5 sheets of kevlar and 3 Sheets of glass). Meanwhile, the fibers are fabricated using vacuum bagging process. In addition to the epoxy, the catalyst and the nanoparticle added to the resin to increase the strength of the laminates. The water droplet model is designed using Smoothed-particle hydrodynamics (SPH) modelling with the aid of Navier Stokes equation. Furthermore, the water is impinged using an elliptical spray nozzle at a constant height of 100m. For feasibility, the small part of the composite wing structure is exposed to the impact of water droplet at different velocity ranges from 0 to 40m/s. Subsequently, the behaviour of the droplet is studied for three various crosswind effects of 15m/s and 25m/s. From the results, it is clear that the stress and strain are depending on the impact velocity of the droplets. On the contrary, the damage is very little which does not cause any deformation or failure of the structure of the airplane. The numerical observations results are in reasonable and acceptable.
A robust numerical scheme for transcritical flow simulation in a Braided river
Authors: Kumar Sarma Arup , Baruah Anupal J 
Published: August 2019

Abstract
Flow simulation over a braided channel is a challenging task as in the monsoon season flow moves over an undulating bed while as in non-monsoon season or in lean period it moves through several sub-channel. Therefore a more robust scheme is necessary for simulating such kind flow particularly when transcritical flow occurs in river reach. Shallow water equations can be derived by depth integration of the Navier Stokes equation and assuming hydrostatic pressure distribution. These equations are basically based upon the conservation of mass and momentum approach. Shallow water equations are a set of a first-order nonlinear hyperbolic partial differential equation and do not have closed form of analytical solution without considering a large number of approximation because of which these equation needs to be solved by different numerical techniques like finite difference, finite element, and finite volume. The hyperbolic nature of the equations results in a generation of numerical dispersion in the solution domain because of which proper shock capturing methods need to be implemented along with the scheme. The presence of bed slope term in the governing equations causes some difficulty to apply them in complex bathymetry. Researchers have modified the original form of governing equations so that these equations can be implemented in a complex topography with proper mass conservation. In this paper, the modified form of the 2D governing equation is combined with the proper shock capturing technique to investigate the applicability of the scheme in complex bathymetry. This scheme is used as an integral part of BRAHMA model (Braided River Aid: Hydro-Morphological Analyser) developed by IIT-Guwahati in collaboration with Brahmaputra Board. Governing equations solved by Mac Cormack predictor-corrector scheme and the scheme has been tested with some classical problem including dam break, quiescent water above an irregular bed, steady flow over an irregular bed, transcritical flow over a bump etc. For each test case numerical results are compared with the analytical result and found satisfactory.
Suitability of pineapple leaf fiber for the reduction of noise in aircraft power plants
Authors: Manigandan S. , Ramanathan Muthiaya , kumar Dinesh , Nithya S. , Gunasekar P. , Devipriya J. 
Published: August 2019

Abstract
The application of natural fiber replacing metals is growing rapidly. Among the various natural fibers pineapple leaf fiber gaining the attention of pioneers due to its high strength and deformation resistance. This paper studies the effect of pineapple fiber when the mixed with graphene nanocomposites for the aerospace applications. Pineapple leaf fibre (PLF) is well-known natural fiber for its rich cellulose content. Moreover, this paper studies the topological properties of Pineapple leaf graphene fiber. Additionally the noise and vibration absorption capacity of the fiber also calibrated. During the operation of aircraft power plant the unwanted acoustic noise generated by the aircraft is massive. Usually, these noises are not absorbed by metal bodies. These unwanted noises will aid passenger discomfort. The test relieves the homogenous pineapple fiber doesn’t show a profound effect in absorbing the noise and vibration. This drawback is overcome by adding nanoparticle graphene. The graphene is mixed with epoxy in three varies in proportions 3%, 4% and 8% to form tested specimen P3, P4 and P8. From the results, it is clear that P8 shows an intense effect in the increase of strength to weight noise and the noise characteristics nearly 18% compared to other fibers.
Study of Heat Conduction inside Rolling Calender Nip for Different Roll Temperatures
Authors: Gupta Neelam , Kanth Neel 
Published: August 2019

Abstract
Calendering is a smoothening process at the final stage in textile industry, where fabric passes through the nips formed by two or more rolls in contact. The material used for making of rolls varies for different types of calenders. Depending on the quality of fabric required these rolls are hard or soft and can be heated to certain temperature, using induction process, hot water passage or heated oil passage inside the rolls. In rolling calendering process, fabric is pressed between two or more rolls, where nip is formed by the combination of alternate hard and soft rolls. In this paper effect of roll temperature and bonding time on fabric temperature has been discussed using single nip rolling calender, when fabric is inside the calender nip formed by hard and soft rolls having different temperatures using one dimensional unsteady state heat conduction equation.
Parametric study and efficiency optimization of the solar coupled hybrid micro gas turbine power plant for high altitude flight.
Authors: Thomas Jayachandran A V , Gangisetty G , Tkachenko A , Rybakov Viktor 
Published: August 2019

Abstract
The performance and feasibility study of a hybrid system designed by combining solar micro gas turbine for power generation process during high altitude flight were explored. The high altitude flight could be defined as long duration stratosphere balloon. Payloads in this high altitude balloon flight could be remote sensing satellites or communication satellites which require a continuous high-density power supply that cannot be provided by solar panels. To reduce greenhouse gas emission, the hybrid method was chosen and studied for its effectiveness in a gas turbine power plant. A thermodynamic cycle analysis for high altitude gas turbine power generator was analyzed along with various power conversion systems and recuperator placement configurations were investigated. The working parameters such as Overall Pressure Ratio and Turbine inlet temperature was investigated with the thermo gas dynamic calculation for designing an optimized power plant. Parametric optimization for determining the realistic and practical combination of recuperators for improving the specific fuel consumption and overall efficiency of the Micro gas turbine power plant was performed. The recuperators could be positioned either in the exhaust of a high-pressure turbine or at the exhaust of the free turbine. The recuperator position and heat extraction are explored and the resulting data depicts the recuperator surface area increases the effectiveness thus the fuel consumption decreases but the recuperator increases the overall mass and volume of the power plant size. A comprisable trade-off was made between the recuperator performance and its size and the results are optimized for high overall efficiency of the power plant. A short trade-off between the selected system and existing systems were made. The system performance, Efficiency optimization and the component size and weight characteristics were performed to deliver maximum payload capabilities.
Thermal Testing of Wax Layer Thickness in Crude Oil Pipeline
Authors: Alnaimat Fadi , Mathew Bobby , Ziauddin Mohammed 
Published: August 2019

Abstract
This article investigates thermal detection method for wax layer thickness inside pipeline. Crude oil temperature decreases as it flows through pipeline and this causes the wax to precipitate out of solution. Wax deposition increases the viscosity significantly near the wall as it solidifies. The proposed method of thermal wax testing of different operating conditions is investigated through this research. In order to determine the layer thickness using fluid and heat transfer analysis and obtain velocity and temperature distributions, mathematical modelling is achieved. The effect of different layer thicknesses on temperature and flow characteristic such as velocity and pressure distribution are examined in this study. The method is examined for different Reynold numbers and flow characteristic and wax thickness are examined. The proposed method is expected to be accurate, efficient and cost effective for online testing of wax layer thickness which find immediate utility in oil and gas operation.
Passive Heating and Cooling Potential Strategies: A Comparison between Moderate Summers and Warm Winters Climate Zones
Authors: Alhamad Issah M. , AlSaleem Moamin , Taleb Hanan 
Published: August 2019

Abstract
In this work, a comparison between different potential natural ventilation strategies used in different climate zones are investigated. As an example of moderate summer climate zone, London city has been selected, while Dubai city has been selected as a warm winter climate zone. The influence of external wind speed and pressure was studied using Autodesk Flow Design Software. Then CFD simulations have been generated inside the building using IES Virtual Environment software to study the indoor ventilation (Micro-Flow analysis) and to demonstrate the success of the adopted potential strategies in enhancing the indoor climate conditions. Hourly Analysis Program (HAP) was used to calculate the cooling/heating load of the building and to check the energy savings. The results demonstrated that comfort conditions within the interior space of the building were met during certain months of the year using passive heating/cooling strategies alone (without the need of HVAC system). HAP energy modeling results showed that the annual space cooling for Dubai model dropped from almost 58,000 kW per year to almost 42,000 kW with a total energy savings of 18.6% (including all energy consumption parameters). On the other hand, London model results showed that the annual interior space heating dropped from almost 36,000 kW to almost 28,000 kW with a total energy savings of 16.4%.
Passive solar design for energy efficiency in buildings in composite climate
Authors: Charde M , Gupta R , Vemuri A , Kheterpal A , Bhati S 
Published: August 2019

Abstract
Renewable energy sources offer an unlimited supply of energy. Solar energy can be utilized to supplement energy needs of a building either passively or actively. It is feasible to reduce consumption of energy usage for heating, cooling and lighting requirements of a building by adopting a climate sensitive approach for design of building elements like static sunshade, wall and roof. To study the effect of passive building elements in composite climate zone, four rooms were designed with a different combination of type of static sunshade, wall and roof. The static sunshade and brick cavity wall with brick projections were designed using sunpath diagram and shadow angles. Air cavity was introduced in the reinforced cement concrete (RCC) roof by laying hollow stoneware pipes. This paper presents theoretical and simulation studies to compare thermal performance of the four rooms. Theoretically, the four rooms were compared by steady state method based on total heat load in every month and on representative days in different seasons throughout the year. The extreme and most frequently occurring temperature values (mode) in every season were identified by obtaining the frequency distribution of the outdoor air temperature with the software SPSS Statistics (IBM Corp. 2012). Results showed that room with designed passive elements gained minimum heat in summer and moderate summer, while it lost minimum heat in winter and moderate winter. This shows the effectiveness of the designed passive elements in insulating the room interiors from the extreme climatic conditions. The rooms were also simulated using software Autodesk Ecotect Analysis 2011 and their performance was compared on a typical day in each month. Results showed that this software can be helpful for preliminary design to get an idea about the room performance that can help to create thermally comfortable indoor environment for the well being of occupants.
Gasification of powdered coal in filtration regime with a super adiabatic heating
Authors: Zaichenko A.Yu. , Podlesniy D.N. , Salganskaya M.V. , Tsvetkov M.V. , Salgansky E.A. 
Published: August 2019

Abstract
A new method is proposed for gasification of a powdered coal in filtration regime with superadiabatic heating. The fuel is supplied suspended with the flow of oxidant gas, whereas the gas flow filters through a porous bed of large particles making a heat recovery medium. Owing to the heat exchange between countercurrent solid and gas flows part of the heat is recuperated and transferred from the products to the reaction zone. The heat accumulation in a relatively narrow combustion zone can result in the temperature within the combustion front substantially higher than the adiabatic temperature calculated for the initial temperature of the reactants being that ambient and the heat of the reaction is evenly distributed over the products.
Atomic and molecular spectral line shapes in laboratory and selected astrophysical plasma
Authors: Parigger C G , Helstern C M , Gautam G , Drake K A 
Published: August 2019

Abstract
This work elaborates on laboratory measurements of hydrogen Balmer series lines and diatomic molecular species in laser-plasma. Comparisons with astrophysical white dwarf spectra, recorded at various observatories and the Hubble space telescope, point out direct applications of experimental results. The recorded general relativity gravitational- or Einstein-shift of the atomic lines allows one to infer the ratio of mass and radius. The Stark-effect redshifts of hydrogen alpha and hydrogen beta lines investigated with time-resolved emission spectroscopy are usually one order of magnitude larger than the gravitational shift. In view of white dwarf atmospheres dominated by hydrogen and the associated absorption spectra, averaging the laser-induced plasma data reveals spectral line shapes that mask the redshift caused by the Stark effect. The available white dwarf data indicate that the collected radiation propagated through regions of different density in the star’s atmosphere. Diatomic spectra are typically recorded as white dwarfs further progress in their transformation.