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Design Optimization and Aerodynamic Analysis of a Hybrid Blended Wing Body- VTOL Unmanned Aerial Vehicle

Delhi Technological University-Pranav Bahl, Vikas Rastogi, Amit bainsla, Nitin Sharma
  • Technical Paper
  • 2020-01-0472
To be published on 2020-04-14 by SAE International in United States
Unmanned Aerial Vehicles (UAVs) can be effectively used to serve humanitarian relief efforts during environmental disasters. Designing such UAVs presents challenges in optimizing design variables such as maximizing endurance, maneuverability and payload capacity with minimum launch and recovery area. The Blended Wing Body (BWB) is a novel aircraft configuration offering enhanced performance over conventional UAVs. Designing a blended wing configuration UAV takes into account interdependency between aerodynamic performance and stability. Designing BWB is peculiar and is investigated in this paper with a view to achieve an aerodynamically stable and structurally sound configuration. The designed UAV is a hybrid of a tailless blended-wing-body and a tri-copter configuration with two forward tilt motors for transition into cruise flight after vertical take-off and back to multirotor while landing (VTOL-Vertical Take Off and Landing). The BWB is iteratively optimized in XFLR-5 for Dynamic and static stability. The wing design was optimized for aerodynamic and structural fitness in MATLAB using Meta-heuristic optimization methodology based on genetic evolutionary algorithm. The 3D CAD design was conceived on SolidWorks and analyzed in Pressure…
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Design of Elevons for a Hybrid VTOL-Blended Wing Body Unmanned Aerial Vehicle

Delhi Technological University-Amit Bainsla, Vikas Rastogi, Pranav Bahl
  • Technical Paper
  • 2020-01-0047
Published 2020-03-10 by SAE International in United States
The two primary requirements for a safe flight of a UAV are its stability and manoeuvrability. The purpose of this study is to design and validate elevons for a UAV having Blended Wing Body configuration which requires knowledge of various domains applied in a complex combination. Elevons are the unconventional control surfaces for the flying wings which will cause a pitching moment when moved in same direction and will cause a rolling moment when moved differentially and their preliminary design is affected by the function which is dominant. A MATLAB© code was written to decide the position, shape and size of elevons and later on accurately evaluated using high fidelity Computational Fluid Dynamics simulations. The MATLAB© code calculates the required roll time rate taking into consideration the longitudinal and lateral control requirements. Using this coupled approach of MATLAB© code and Computational Fluid Dynamics simulations significant optimization is achieved in designing the elevons.

Aerodynamic Effect of Aspect Ratio of Spherical Depressions on the Bonnet of Hatchback Cars

Delhi Technological University-Vishesh Kashyap, B.B. Arora, Sourajit Bhattacharjee, Priyanshu Mittal
  • Technical Paper
  • 2019-01-5096
Published 2019-12-30 by SAE International in United States
Flow separation is one of the primary causes of increase in form drag in vehicles. This phenomenon is also visible in the case of lightweight vehicles moving at high speed, which greatly affects their aerodynamics. Spherical depressions maybe used to delay the flow separation and decrease drag in such vehicles. This study aims for optimization of aspect ratio (AR) of spherical depressions on hatchback cars. Spherical depressions were created on the bonnet of a generalized light vehicle Computer-Aided Design (CAD) model. The diameter of each spherical depression was set constant at 60 mm, and the center-to-center distance between consecutive spherical depressions is fixed at 90 mm. The AR of spherical depressions was taken as the parameter that was varied in each model. ARs 2, 4, 6, and 8 were considered for the current investigation. Three-dimensional (3D) CFD analyses were then performed on each of these models using a validated computational model. Vehicle travel velocities of 22, 24, 26, 28, and 30 m/s, which were nondimensionalized for scaling the results, were considered for analyses, in order…
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Optimization of Race Car Front Splitter Placement Using CFD

Delhi Technological University-Sourajit Bhattacharjee, B.B. Arora, Vishesh Kashyap
  • Technical Paper
  • 2019-01-5097
Published 2019-12-30 by SAE International in United States
The behavior of flow over an automobile’s body has a large effect on vehicle performance, and automobile manufacturers pay close attention to the minimal of the details that affect the performance of the vehicle. An imbalance of downforce between the front and rear portion of the vehicle can lead to significant performance hindrances. Worldwide efforts have been made by leading automobile manufacturers to achieve maximum balanced downforce using aerodynamic elements of vehicle. One such element is the front splitter. This study aims to analyze the aerodynamic performance of automobile at various splitter overhang lengths using Computational Fluid Dynamics (CFD). For the purpose of analysis, a three-dimensional (3D) CFD study was undertaken in ANSYS Fluent using the realizable k-ε turbulence model, based on the 3D compressible Reynolds-Averaged Navier-Stokes (RANS) equations. The National Advisory Committee for Aeronautics (NACA) 4412 was taken as profile for the fixed-length splitter attached to a NASCAR 2019 model body. Vehicle speeds of 200, 250, and 300 km/h were considered in order to simulate the velocity of a race car. Drag coefficient, lift…
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Effect of Fender Coverage Angle on the Aerodynamic Drag of a Bicycle

Delhi Technological University-Vishesh Kashyap, B.B. Arora, Sourajit Bhattacharjee
Published 2019-10-11 by SAE International in United States
While riding cycles, cyclists usually experience an aerodynamic drag force. Over the years, there has been a global effort to reduce the aerodynamic drag of a cycle. Fenders affect the aerodynamic drag of a cycle to a large extent, and fender coverage has a pronounced effect on the same. In this article, various fender coverage angles, varying from 60° to 270°, were studied to predict the aerodynamic drag with the help of a validated CFD model in SolidWorks Flow Simulation. The model was based on the Favre-Averaged Navier-Stokes (FANS) equations solved using the k-ɛ model. It was predicted that aerodynamic drag coefficient reduced fender coverage angle up to 135°, and thereafter started increasing. Analyses were carried out at velocities of 6 m/s, 8 m/s and 10 m/s and the results were found to be similar, with a minimum aerodynamic drag coefficient at 135° occurring in all the cases under study. There was an observed optimum decrease in drag coefficient to the extent of 4.6%, 4.5% and 4.6% as compared to the bicycle without fenders for…
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Computational Analysis of Flap Camber and Ground Clearance in Double-Element Inverted Airfoils

Delhi Technological University-Vishesh Kashyap, Sourajit Bhattacharjee
Published 2019-06-11 by SAE International in United States
Drag and lift are the primary aerodynamic forces experienced by automobiles. In competitive automotive racing, the design of inverted wings has been the subject of much research aimed at improving the performance of vehicles. In this direction, the aerodynamic impact of change in maximum camber of the flap element and ground effect in a double-element inverted airfoil was studied. The National Advisory Committee for Aeronautics (NACA) 4412 airfoil was taken as the constant main element. The camber of the flap element was varied from 0% to 9%, while ground clearance was varied from 0.1c to 1.0c. A two-dimensional (2D) Computational Fluid Dynamics (CFD) study was performed using the realizable k-ε turbulence model in ANSYS Fluent 18.2 to analyze the aerodynamic characteristics of the airfoil. Parameters such as drag coefficient, lift coefficient, pressure distribution, and wake flow field were investigated to present the optimum airfoil configuration for high downforce and low drag. It was observed that while an increase in flap camber improves the lift coefficient substantially, this change is dependent on the angle of attack…
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Experimental Investigations of Metal Oxide Nano-Additives on Working Characteristics of CI Engine

Delhi Technological University-Subham Mukhopadhyay, Aahan Malhotra, Mukul Tomar, Naman Choudhary, Naveen Kumar
Published 2019-04-02 by SAE International in United States
Biodiesel is a potential substitute for diesel and extensive research is carried in India on production and utilization of biodiesel from a variety of edible/non-edible, animal fat and waste oils. However, issues like stability, clogging, increased NOx, and high consumption rate etc. are some of the critical issues which are associated with long-term use of these alternative fuels in a diesel engine. The recent developments in science and technology may have concreted a method to create nano measure vigorous resources that have incredible benefits to micron sized constituents. Nano liquids may be a fresh period of compact-fluid complex constituents comprising of nano sized concrete elements disseminated into a base liquid. The present study investigates the effect of doping metal oxides nanoparticles with waste fish oil-based biodiesel. For the present study, the blends of fuel are prepared by using 30ppm each of titanium dioxide and alumina nanoparticles respectively. The addition of nano-additives in biodiesel is achieved using an ultra sonicator, to achieve unvarying postponement. A series of experiments have been conducted to evaluate the performance and…
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Experimental Study of Sliding Wear Behavior of the Casted Lead Bronze Journal Bearing Material

Delhi Technological University-Ramesh Chandra Singh, Rajiv Chaudhary
Maharaja Agrasen Institute of Technology-Vipin Kumar Sharma
Published 2019-04-02 by SAE International in United States
Lead (Pb) bronze material is used for the manufacturing of bearings. Lead provides less friction and wear-related properties to bronze. During working of the bearings the lead contained micro-chips mixes with the lubricant oil and makes its disposal difficult. Rotational speed and applied load are the two main parameters on which the working and amount of wear from the bearing depend. So it is important to find out an optimum set of speed and pressure on which a particular bearing should operate to minimize the wear and hence minimize the lead-contaminated lubricating oil. In the present work, Taguchi technique has been used to find out the optimum values of speed and pressure. To measure the specific wear rate (SWR) and coefficient of friction (COF) of the leaded bronze material, it is made to slide on a mild steel material and amount of wear and coefficient of friction has been recorded using a pin on disc machine using ASTM-G99 standards. Experimental tests were conducted at different sliding speed (3.01, 3.95, 4.52, 4.62, 4.72 m/s) and pressure…
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Effect of Using Exhaust Gas Recirculation (EGR) on the Emission Characteristics of the CI Engine Fuelled by Acetone-Butanol-Ethanol (ABE) Diesel Blends

Delhi Technological University-Naveen Kumar
CASRAE, Delhi Technological University-Aahan Malhotra, Mukesh Yadav, Mukul Tomar, Shikhar Jain
Published 2019-04-02 by SAE International in United States
The power generation, agriculture, and transportation sectors are dominated by diesel engines due to better thermal efficiency and durability. Diesel engines are also a major contributor to the air pollutants such as NOx and particulate matter. Acetone-butanol-ethanol (ABE) is considered a promising alternative fuel as it emits less pollutants compared to conventional fuels. In current work, the ABE used was of the ratio (3:6:1) and four samples were prepared for engine trial ABE (10%90%diesel), ABE (20%80%diesel), ABE (30%70%diesel) and ABE (40%60%diesel). Their physio-chemical properties like kinematic viscosity, density, specific gravity and calorific value were checked and tested on compression ignition engine at different operating parameters. The experimental work was conducted upon Kirloskar 4-stroke single cylinder, vertical, air-cooled 661cc compression ignition engine at different speeds and loads. The operational parameters taken were injection temperature, injection pressure and injection timings. The main aim of the current work is to find the effect of exhaust gas recirculation (EGR) on the emission characteristics of acetone-butanol-ethanol (ABE) blends with diesel in compressed ignition engine. Exhaust gas recirculation (EGR) is a…
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Study of Performance and Emission Characteristics of Propan-2-ol and Gasoline Fuel Blends in an Unmodified Spark Ignition Engine

Delhi Technological University-Mukul Tomar
CASRAE, Delhi Technological University-Naveen Kumar, Shikhar Jain, Aakriti Bagla, Shivalika Sharma
Published 2019-04-02 by SAE International in United States
In view of the rapid depletion, increasing prices and uneven distribution of conventional petroleum fuels; the interest in the use of alternative fuels has increased exponentially. Fuels such as biodiesel & alcohol have been evaluated both at experimental and commercial scale due to improved emission characteristics as compared to conventional fuels. Alcohols are oxygenated and result in improving the engine performance. As a blend with conventional gasoline, the alcohols enhance the premixed and diffusive combustion phase which improves the combustion efficiency. The present investigation evaluates studies on stability and homogeneity along with physicochemical properties like density, viscosity, calorific value, copper-strip corrosion and solubility at room temperature of Propan-2-ol and gasoline blends. Comprehensive engine trials on unmodified petrol engine fuelled with blends of Propan-2-ol and gasoline blends in the proportions of 5, 10, 15 and 20% by volume have been conducted. The performance characteristics e.g. brake-specific energy consumption, brake thermal efficiency and emissions characteristics such as NOX, CO and HC were studied and analyzed to evaluate the optimum alcohol/fuel blend for the petrol engine. The result…
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