Engineering Commons^™

Numerical Investigation Of Flow Over An Airfoil With Active Cavity, Ahmed Elbaz

Mechanical Engineering

Wind turbine blades are commonly made of airfoils due to their high lifting characteristics. The performance of the airfoils can reach higher optimal conditions with applying various modifications on the airfoil geometry.  The need to improve airfoil performance at low values of Reynolds number is essential to small power wind turbines. Therefore, the objective of this study is to investigate methods to increase the lift to drag ratio, which results in better aerodynamic performance of the airfoil used in wind turbines at low Reynolds number using active flow control by employing a surface cavity with suction. The investigation considered both …

Hypersonic Heat Transfer Load Analysis In Star-Ccm+, Robert Comstock

Master's Theses

This thesis investigates the capabilities of STAR-CCM+, a Computational Fluid Dynamics (CFD) software owned by Siemens, in predicting hypersonic heat transfer loads on forward-facing surfaces. Results show that STAR-CCM+ predicted peak heat transfer loads within +/- 20% of experimental data on the leading edge of a delta wing design from the X-20 Dyna-Soar program with 73^o of sweep. Steady-state laminar simulations were run as replications of wind tunnel tests documented in NASA CR-535, a NASA technical report that measured and studied the hypersonic pressure and heat transfer loads on preliminary X- 20 wing designs across a wide range of …

Improvement Of Labyrinth Seal Leakage Rates Using Additive Manufacturing, Austin L. Gasbarra

Master's Theses

The growing popularity of additive manufacturing in commercial applications has al- lowed for new ideas and new ways of thinking when designing components. Further optimization at the component level is possible, though powder metallurgy is in its infancy. This study explores the possibility of using additive manufacturing to develop better labyrinth seals in turbomachinery. Labyrinth seals have a torturous fluid path with high losses, thus limiting the amount of fluid leakage. These types of seals can be non-rotating, allowing them to better take advantage of the additive manufacturing process due to the absence of rotating stresses. Labyrinth seal performance is …

Numerical Analysis Of A Circulation Control Wing, Luke W. Bodkin

Master's Theses

The objective of this thesis was to develop an experimental method to research circulation control wings using numerical analysis. Specifically, it is of interest to perform 3D wind tunnel testing on a circulation control wing in the Cal Poly Low Speed Wind Tunnel (CPLSWT). A circulation control wing was designed and analyzed to determine the feasibility of this testing.

This study relied on computational fluid dynamics (CFD) simulations as a method to predict the flow conditions that would be seen in a wind tunnel test. A CFD simulation was created of a wing model in a wind tunnel domain. Due …

The Effect Of Guide Vane Opening Variations And Total Blades On Cross Flow Turbine Performance Using Computational Fluid Dynamic, Muhamad Akbar Navis, Heru Suryanto, Putut Murdanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is an agrarian country that continuously produces water, so it has the potential to develop a hydroelectric power plant. Computational Fluid Dynamic (CFD) application could be used to be an economical, quick, and efficient approach to improve the engineering design and turbine performance. This research aimed to find the effect of guide vane opening variations and total blades on cross-flow turbine performance using CFD simulation. This research used experimental modelling method with ANSYS program for turbine design with 22, 24, and 26 turbine blades and guide vane opening variations of 12°, 16°, 20°, 24°, and 36°. The data were …

Attaining The Appropriate Simulation Program Towards Better Environmental Decisions, Adeeb Sidani, Osama Omar

Architecture and Planning Journal (APJ)

Global Warming is one of the greatest environmental threats of the 21st century. Many parties around the world like governments, corporations, and researchers, etc. are working hard to find solutions. Architectural education is concerned with global warming issues, and trying to achieve reliable design related solutions for a sustainable environment. Majority of the students use simulation programs to determine with accuracy some variables that can support designers to take decisions about the best strategies to apply for any type of building. These simulation programs are usually selected based on their straightforward and user-friendly interface. The most common programs among architecture …

The Use Of Three-Dimensional Conjugate Cfd To Enhance Understanding Of, And To Verify, Multi-Modal Heat Transfer In Dynamic Laboratory Test Walls, Rakshit D. Muddu, Timothy Patrick O'Leary, Ronan Hogan, Anthony James Robinson, Aimee Byrne

Articles

This work describes the use of conjugate computational fluid dynamics (C-CFD) to simulate controlled laboratory based dynamic heat transfer tests on building components. This study proposes that conjugate CFD simulation can be used to evaluate the influence of combined convective and conductive heat transfer in multi-state building components. To this end, a solid wall and cavity wall were tested with a Calibrated Hotbox and subject to variable temperature conditions leading to combined convective and conductive heat transfer. The varying temperature of the heat source was monitored and used as the input boundary condition in the simulation model, which included a …

Scale And Numerical Modeling To Determine Operating Points Of A Non-Clogging Vortecone Filter In Mining Operation, Ashish R. Kumar, Sampurna Arya, Adam Levy, Steven Schafrik, William C. Wedding, Kozo Saito

Progress in Scale Modeling, an International Journal

Numerical and scale modeling studies of Vortecone, a pressure-driven wet-scrubber device for the efficient capture of over-sprayed paint in the automobile industry, are presented. In this manuscript, Vortecone was tested for removing dust particles from underground mining operations. The pressures required to operate Vortecone and the airflow rates through the Vortecone are the two most important factors for mine ventilation systems. This study used dry, no-particle conditions to obtain relationship between these two parameters and then designed a Vortecone filter ventilation system for mining operations. Commercial software, SC/Flow, was used to generate the CFD model with unstructured meshes and a …

Scale Modeling Of Dust Capture Through A Flooded-Bed Dust Scrubber Integrated Within A Longwall Shearer, Sampurna Arya, Ashish Kumar, Kozo Saito, Thomas Novak, Adam Levy

Progress in Scale Modeling, an International Journal

Meeting federal dust standards at a longwall mine face is among the more difficult challenges for a longwall mine operator. With recent changes in federal dust regulations requiring lower worker exposure, maintaining compliance has become increasingly difficult. The authors recommend the concept of controlling respirable and float dust, which is inherent in longwall mining, through the application of a flooded-bed dust scrubber to a longwall shearer. A full-scale physical model of a longwall shearer, modified with an integrated flooded-bed scrubber, was designed and fabricated at the University of Kentucky to measure the effects of a flooded-bed scrubber on dust capture …

Characteristics Study Of Internal Gas-Liquid Two Phase Flow Field Of Three Layers Of Air Stirred Tank Reactor, Xiaodong Hu, Dexin Zhang, Jiang Rong, Zenghui Wu, Tian Qiang

Journal of System Simulation

Abstract: The fluid dynamics and the gas-liquid distribution character in a three-layer stirred tank reactor with 2KSX (four wide blade propeller type stirrer) and PDT (parabolic disc turbine) were analyzed with the MRE (multi-reference frame) method based on Euler-Euler and population balance models. The total and local gas-hold were calculated. The conclusions show that: axial flow was produced by double stir upper KSX with radial flow produced by the third layer of PDT, gas-hold was improved with double-upper-layer stirrers axial driven and the lowest stirrer axial driven, gas-hold increased with the stirred time going on, which would not be extended …

Modeling And Simulation Of A Supercritical Co2-Liquid Sodium Compact Heat Exchanger For Sodium Fast Reactors, Hailei Wang, Sean M. Kissick

Mechanical and Aerospace Engineering Faculty Publications

The study focuses on modeling and simulations of sodium-sCO2 intermediary compact heat exchangers for sodium-cooled fast reactors (SFR). A simplified 1-D analytical model was developed in companion with a 3-D CFD model. Using classic heat transfer correlations for Nusselt number, some simulation results using the 1-D model have achieved reasonable match with the CFD simulation results for longer channels (i.e., 40 cm and 80 cm). However, for short channel (10 cm) when axial conduction within the sodium fluid is significant, the 1-D model significantly over-predicted the heat transfer effectiveness. By incorporating the temperature-jump model, the 1-D model can extend its …

Co-Milling And Cofiring Of Woody Biomass With Coal In Utility Boilers: Enabling Technology Through Experiments And Modelling, Seyedhassan Fakourian

Theses and Dissertations

Beetle-killed trees and woody residues degenerate and may lead to wildfires and uncontrolled CO2 emission. Woody biomass is known as a neutral CO2 solid fuel since it generates the same amount of CO2 that takes from atmosphere during its growing up. Cofiring woody biomass with coal in existing coal power plants is a reasonable solution to reduce the net amount of CO2 emission and decrease the risk of wildfires. However, there are some challenges ranging from providing and handling the woody biomass to the operation of cofiring woody biomass with coal. Co-milling of the fuels and ash deposition on the …

Analysis Of One Way Valve Mechanism For Wings Of A Flapping Drone, Xinchen Deng

Student Works (2020-2029)

The flapping drone is one type of MAVs which is defined as a miniature unmanned aerial vehicle that is inspired by flying birds and insects. Flapping wings can make a perfect combination of thrust and lift by flapping up and down with full usage of unsteady air. The flapping drone has the advantages of high maneuverability and a special lift generation mechanism. Compared with rotary-wing or fixed-wing MAV, it is smaller, lighter, and has higher flight performance. It can quickly change the flight direction and flight speed by control the flapping frequency and it is the only flight mode that …

Venturi Flowmeter Performance Installed Downstream Of The Branch Of A Tee Junction, Benjamin G. Sandberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to evaluate the influence of a tee junction on flow rate measurement of a Venturi flowmeter installed downstream of the branch of a tee. Accuracy in flow measurement is important to organizations where miscalculated flow rates can add up to be millions of dollars in either lost revenue, overcharges to the client, or improper system operation. This research used Computational Fluid Dynamics (CFD) to determine ratios by which the manufacturer’s straight-line calibrated C_d (discharge coefficient) can be adjusted to improve the accuracy of the flow measurement when the Venturi is installed on the …

Chimera Grid Methods Applied In Astronautics Aerodynamic Problems, Yuan Wu

Journal of System Simulation

Abstract: Structured chimera grid method has been considered as the most applicable technology to solve aerodynamic problems of multi-component configuration aircraft at current stage. Therefore, by using structured chimera technology and CFD method, two typical aerodynamic problems of conventional tactics missile configuration with rudder deflection were thoroughly investigated: i) a simple and practical linear modification model for micro unsymmetry configuration was proposed which could effectively reduce the range of error and eliminate its skewness properties caused by asymmetric separation vortex, while the traditional method introduced lateral aerodynamic error in data transformation; ii) 3-tunnel linear adding model was investigated and the …

Computational Investigation Of The Effects Of Rotor-On-Rotor Interactions On Thrust And Noise, Austin R. Schenk

Theses and Dissertations

Recent advancements in electric propulsion systems have made electric vertical takeoff and landing aircraft a reality, and one that is seen as a partial solution to the growing issue of urban traffic congestion. Designing an aircraft with multiple smaller motors and rotors spread across the wings–referred to as distributed electric propulsion (DEP)–has shown great potential in help- ing improve electric aircraft performance by offering increased propulsive efficiency, augmented lift, and structural load distribution. For these reasons, DEP is one configuration that is currently being implemented into multiple prototype designs (e.g. NASA’s Maxwell X-57, Airbus Vahana, Opener BlackFly, and Joby S2). …

Numerical Simulation And Aerodynamic Effect Research For Multi-Warhead Projection, Yuan Wu

Journal of System Simulation

Abstract: In order to study the complex aerodynamic problem in multi-warhead projection, and also establish the practical analysis method for nonlinear aerodynamic characteristics, the separation process was simulated by using CFD technology as well as Monte Carlo method for a statistical research, while effects of the projection condition, multi-body intervene and unsteady characteristic during the separation process were discussed. The present research shows that the main forms of the submunition movement are radial separation and pitching movement; the direction of mass center motion and attitude motion is determined by the projection condition, however the attitude motion is also sensitive to …

Numerical Simulation Of Diffusion Regularity Of Co In Fire Smoldering Phase In Aircraft Cabin, Jiaquan Lin, Ruiting Wang, Pi Jun, Ma Min, Jianzhong Yang

Journal of System Simulation

Abstract: In order to study the impact of the cabin air conditioning supply velocity on CO diffusing in the fire smoldering phase and the effect of the transportation of CO to human body, a simulation model of A320 aircraft cabin was established, and velocity field and CO concentration field under the different air supply velocity were simulated based on the fluid dynamics control equations. The relationship between the air conditioning supply velocity and the value of CO concentration as well as the diffusion area was obtained by the analysis of the transportation of CO in different directions. The drainage efficiency …

Cp Check Valve Design, Alec B. Der Matoian, Jessica M. Dent, Skylar M. Tusting

Mechanical Engineering

This report is to serve as a final design review and update to the project sponsors at Zurn Wilkins for the Check Valve Design Senior Project. The senior project team was tasked with improving upon the design of Zurn Wilkins’ backflow prevention assembly for small diameter pipes by reducing the pressure loss created by the check valves within the double check backflow assembly. The information contained in this report builds off the information contained in the Critical Design Report (CDR), as well as feedback and further investigation suggested during an Intermediary Design Review. Based on conclusions from the CDR, our …

Heat Transfer Analysis Of A Data Centre, Arumainathan Kabildev

Student Works (2020-2029)

Data centres are an integral part of networking as it houses servers that facilitate incoming and outgoing data flow. A resolute cooling approach is needed to overcome the hot air dissipated by these servers. This research focused on the computational fluid dynamics (CFD) simulation of the heat transfer modelled upon Telekom Malaysia (TM) City’s data centre 3. The simulation was carried out to ascertain the heat distribution across the data centre by using ANSYS Fluent. The results indicated that the server racks’ inlet temperature reaches 29.79 oC, which is close to the maximum permissible limit according to recommendations provided by …

A Study Of The Utilization Of Panel Method For Low Aspect Ratio Wing Analysis, William Barton D. Newey

Master's Theses

This study demonstrates the applicability of using a modified application strategy of panel method to analyze low aspect ratio wings at preliminary design phases. Conventional panel methods fail to capture the leading edge vortex (LEV) that is shed by wings with low aspect ratios, typically below 2 depending on planform. This aerodynamic phenomenon contributes to a significant amount of the lift of these wings and the result is a drastic underestimation of the lift characteristics when analyzed by conventional panel method. To capture the effect of the leading edge vortex, a panel method code was used with an extended definition …

Optimization Of Window Positions For Wind-Driven Natural Ventilation Performance, Nari Yoon, Mary Ann Piette, Jung Min Han, Wentao Wu, Ali Malkawi

Civil and Architectural Engineering Faculty Research

This paper optimizes opening positions on building facades to maximize the natural ventilation’s potential for ventilation and cooling purposes. The paper demonstrates how to apply computational fluid dynamics (CFD) simulation results to architectural design processes, and how the CFD-driven decisions impact ventilation and cooling: (1) background: A CFD helps predict the natural ventilation’s potential, the integration of CFD results into design decision-making has not been actively practiced; (2) methods: Pressure data on building facades were obtained from CFD simulations and mapped into the 3D modeling environment, which were then used to identify optimal positions of two openings of a zone. …

Reinitiation Mode Study Of Highly Irregular Detonation, Nandakumar Vijayakumar

Mechanical and Aerospace Engineering Dissertations - Archive

The propagation of detonation waves is governed by their stability characteristics. Interest in highly unstable detonation grew when early experiments revealed limits of operation to be directly proportional to the stability of detonation. This research focuses on reinitiation pathways of highly irregular self-sustaining detonation. This is an important aspect of stability which is not yet fully understood, while many possible mechanisms have been proposed in the literature. First, a one-dimensional instability model simulation was performed using a global one-step chemistry mechanism to understand the different unstable modes by increasing the activation energy of a mixture of hydrogen and oxygen. The …

Design And Optimization Of Thermal Management Approaches In Data Center Applications, Rajesh Kasukurthy

Mechanical and Aerospace Engineering Dissertations - Archive

In the present day to day life, Internet of Things (IOT) is everything, i.e., Internet and telecommunication is needed for almost every task of our life, which require data centers. These data centers provide various facilities such as, data processing, storage, transmission, maintenance, operations etc., To perform these tasks, a huge amount of power is consumed, which in turn generates large amount of heat. As these data centers are to be made operational throughout the year, cooling of data centers is of utmost importance. The continued increase in heat flux at the chip level due to new and robust technology …

Cfd Analysis On Liquid Cooled Cold Plate Using Copper Nanoparticles, Sarthak Agarwal

Mechanical and Aerospace Engineering Theses - Archive

In today’s world, most data centres have multiple racks with numerous servers in each of them. The high amount of heat dissipation has become the largest server-level cooling problem for the data centres. The higher dissipation required, the higher is the total energy required to run the data centre. Although still the most widely used cooling methodology, air cooling has reached its cooling capabilities especially for High-Performance Computing data centres. Liquid-cooled servers have several advantages over their air-cooled counterparts, primarily of which are high thermal mass, lower maintenance and eventually lower costs by maintenance by labour. Nano-fluids have been used …

Numerical Investigation Of Leading-Edge Modifications Of A Naca Airfoil, Anisur Rahman Ikram

Masters Theses

A parametric investigation was carried out to understand the flow characteristics of tubercle airfoils and to determine the best approach and parameters for designing a tubercle airfoil. For this purpose, a straight edge base airfoil (NACA 4414) and several tubercle airfoils, by modifying the leading edge of the base airfoil, were created in SolidWorks and tested with Computational Fluid Dynamics (CFD) application software Star CCM+.

Alternative tubercle airfoil with elliptical bumps demonstrated superior post-stall performance when compared to their straight edge counterparts; their post-stall lift did not decrease drastically. However, their pre-stall lift coefficients were always lower than the base …

Three-Phase Hydrodynamic Simulation And Experimental Validation Of An Upflow Anaerobic Sludge Blanket Reactor, Camila D' Bastiani, Jéferson Luis Alba, Gabriel Tomazzoni Mazzarotto, Severino Rodrigues De Farias Neto, Anthony Reynolds, David Kennedy, Lademir Luiz Beal

Articles

This research focuses on performing multiphase solid/liquid/gas CFD simulations of a UASB reactor in order to obtain a validated model that provides a clearer understanding of the hydrodynamic behaviour of the three phases in UASB reactors. Eulerian–Eulerian, laminar, three-dimensional, multiphase simulations are carried out using Fluent 16.2. The liquid phase velocity and flow profile are validated through PIV experiments. A liquid mean velocity difference of 8.45% is found between the experimental and numerical results, thus validating the CFD model. Shadowgraphy is applied successfully to validate the biogas phase velocity and bubble size. Based on the hydrodynamic analysis results, the reactor …

A Cfd Study Investigating Drag Reduction For Different Offset And Inline Distance For Two Trucks Platooning, Wael Mokhtar, Kyle Dinger, Shardul Kachare, Mdrazib Hossain, Colin Britcher

Mechanical & Aerospace Engineering Faculty Publications

The automotive industry invests huge resources to improve fuel consumption of commercial vehicles by improving their aerodynamic efficiency. Recently, numerous studies investigating the effect of platooning on aerodynamic drag of semi-trucks have been performed by researchers indicating a positive impact. For the present study, a three-dimensional computational study was performed to investigate the effect of varying offset and linear distance during platooning on the total drag of two semi-trucks. The study was conducted on a full-scale model using Reynold’s Averaged Navier-Strokes governing equations for a moving ground simulation using the STAR-CCM+ computational package. Furthermore, for turbulence, the standard k- …

Development Of Universal Solver For High Enthalpy Flows Through Ablative Materials, Umran Duzel

Theses and Dissertations--Mechanical and Aerospace Engineering

Atmospheric entry occurs at very high speeds which produces high temperature around the vehicle. Entry vehicles are thus equipped with Thermal Protection Systems which are usually made of ablative materials. This dissertation presents a new solver that models the atmospheric entry environment and the thermal protection systems. In this approach, both the external flow and the porous heat shield are solved using the same computational domain. The new solver uses the Volume Averaged Navier-Stokes Equations adapted for hypersonic non-equilibrium flow, and is thus valid for both domains. The code is verified using analytical problems, set of benchmarks and also a …

Comparison Of Reynolds-Averaged Navier-Stokes Turbulence Models For Simulating Boundary Layers In Hypersonic Flows, Jorge-Valentino Kurose Bretzke

Masters Theses

“This study describes the use of Computational Fluid Dynamics (CFD) codes to simulate hypersonic boundary layers using several different turbulent closure models and comparing Reynolds-Averaged Navier-Stokes (RANS) simulations against Direct Numerical Simulations (DNS) of similar test cases. The test cases in this study consist of a flat plate in a Mach 8 freestream with a zero pressure gradient and wall recovery ratio of 0.48, as well as a Mach 8 axisymmetric nozzle also with a cold wall. The RANS models used in this study are the Spalart-Allmaras model, Baldwin-Lomax model, Menter K-Omega Baseline and Menter K-Omega Shear Stress Transport models. …