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(301 - 313 of 313)
Pages
- Title
- Analysis of Murgue's Theory for Centrifugal Blowers and Pumps
- Creator
- Spitzglass, Jacob M.
- Date
- 2009, 1913
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/analysisofmurgue00spit
Thesis (B.S.)--Armour Institute of Technology
- Title
- SHIP STATE AND COVARIANCE PROPAGATION USING TIME SERIES ANALYSIS AND FORECASTING
- Creator
- Katre, Aniruddha
- Date
- 2014, 2014-05
- Description
-
The Navy's Unmanned Combat Aerial System (N-UCAS) program is currently developing technology for autonomous shipboard landing of unmanned...
Show moreThe Navy's Unmanned Combat Aerial System (N-UCAS) program is currently developing technology for autonomous shipboard landing of unmanned aerial vehicles (UAVs). A high accuracy and high integrity relative navigation algorithm using carrier phase di erential GPS measurements and high rate inertial sensor data has been implemented to land the UAV. Such an algorithm requires ship state information to be broadcast to the aircraft via a VHF data link. The data link is susceptible to failure for reasons such as interference from jamming. This thesis considers the problem of precise ship state propagation on board an aircraft during a data link outage occuring when it is too late for the aircraft to abort its landing approach. Accurately quantifying the estimate error covariance is important for a high integrity and accuracy navigation algorithm. Therefore this thesis focuses on algorithms that can propagate the ship state as well as determine the propagation error covariance. Initially, a simple state propagation using kinematic equations for linear motion is tested. Seakeeping and Maneuvering theories used to model the dynamics of a sea vessel are also considered. However, analysis shows that due to constraints imposed by a data link outage and complexity in accurately modeling some parameters in the ship dynamic model, these two approaches are infeasible. As an alternative to kinematic and dynamic modeling, Time Series Analysis and Forecasting methods for ship state propagation are investigated. This work introduces parametric modeling and forecasting of a time series using linear stochastic models. Maximum likelihood estimate (MLE) and outer product of gradients (OPG) algorithms are implemented for faithful parameterization of time series using ARIMA models. Expressions for forecasting and forecast error variance quanti cation are also developed. These algorithms are then tested using ship data provided by the N-UCAS program.
M.S. in Mechanical and Aerospace Engineering, May 2014
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- Title
- A COUPLED LAGRANGIAN-EULERIAN MULTIPHASE MODEL FOR SIMULATION OF WIND TURBINES PERFORMANCE UNDER RAINY CONDITIONS
- Creator
- Cohan, Aiden C.
- Date
- 2016, 2016-05
- Description
-
Wind Turbines power output is constantly influenced by their environmental conditions, including raining and icing. Therefore, understanding...
Show moreWind Turbines power output is constantly influenced by their environmental conditions, including raining and icing. Therefore, understanding the effect of rain is necessary to enhance the efficiency of the wind turbines used in regions with considerable number of rainy days and below freezing temperatures. We developed a multiphase computational fluid dynamics (CFD) model to estimate the effect of rain by simulating the actual physical process of rain droplets forming a water layer over the blades by coupling the conventional Lagrangian Discrete Phase Model (DPM) and the Eulerian Volume of Fluid (VOF) models. We first applied our model to the National Renewable Energy Laboratories (NREL) S809 airfoil used in the blade profile of horizontal-axis wind turbines (HAWT) and studied the effect of rain at different rainfall rates in addition to the effect of surface tension and surface property of the airfoil. Our simulations showed that surface tension has a dominant effect on the performance of the airfoil and should not be neglected under simulated rainy conditions. It also was observed that, under rainy conditions, an airfoil with non-wetting surface has an inferior performance (lower lift and higher drag coefficient) compared to an airfoil with wetting surface due to the added roughness caused by water on the non-wetting surface, which is in line with experimental observations. We also observed that, at low rainfall rates, the performance of the airfoil is highly sensitive to the rainfall rate. However, if the rainfall rate is high enough to immerse most of the airfoil surface under water, a further increase in the rainfall rate does not have a substantial effect on the performance of the airfoil. We also investigated the effect of rain at different angles of attack for two rainfall rates. We started by running single phase cases and observed that our results agreed well with experimental data. We then ran multiphase cases and observed that, lift coefficient increases with angle of attack even past the stall angle compared to the single phase case. However, this favorable increase in lift is accompanied by an increase in the drag coefficient which is greater at larger angles of attack. Finally, we simulated the performance of an actual 3D wind turbine (NREL phase VI horizontal axis wind turbine) for single phase cases at various wind speeds, in addition to, a multiphase case (under rainy conditions) using our multiphase model. Our single phase results compared well with experimental data. We had to use a simplified version of our multiphase model for the multiphase 3D simulation in order to make it computationally affordable. We observed that rain can reduced the performance of the NREL phase VI wind turbine by about 5% at a wind speed of 7.02 m/s and a rainfall rate of 40 mm/hr. Even though we used our multiphase model to simulate water layer formation from rain droplets, the physical concepts used in developing the model are very general and are not limited to this specific problem. Our model can be used to simulate any problem that involves particles hitting a surface and forming a liquid phase. For example, it can be used to model spray painting of a surface as the spray droplets form a paint layer on the surface.
Ph.D. in Mechanical, Materials and Aerospace Engineering, May 2016
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- Title
- Closed nozzle tests of a forty gallon chemical extinguisher
- Creator
- Corman, A., Cowles, R. D., Owen, W. R., Tronvig, W. P.
- Date
- 2009, 1917
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/closednozzletest00corm
Thesis (B.S.)--Armour Institute of Technology
- Title
- The coefficient of friction of ball bearings and horse power to drive
- Creator
- Rehfeldt, H. F.
- Date
- 2009, 1919
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/coefficientoffri00rehf
Thesis (B.S.)--Armour Institute of Technology
- Title
- A commericial test of 350 hp Stirling boiler
- Creator
- Furry, William S, Matchett, James C.
- Date
- 2009, 1907
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/commericialtesto00furr
Thesis (B.S.)--Armour Institute of Technology
- Title
- Coke breeze briquetting
- Creator
- Belke, W. E.
- Date
- 2009, 1918
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/cokebreezebrique00belk
Thesis (B.S.)--Armour Institute of Technology; Biblography: leaf 83
- Title
- Comparative test of centrifugal pressure blowers
- Creator
- Conlin, W. F., Holmes, W. E.
- Date
- 2009, 1909
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/comparativetesto00conl
Thesis (B.S.)--Armour Institute of Technology; Includes index
- Title
- Comparative test of centrifugal blowers
- Creator
- Griffiths, Francis H, Cummins, G. Fred
- Date
- 2009, 1911
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/comparativetesto00grif
Thesis (B.S.)--Armour Institute of Technology, 1911 B.S. in Mechanical Engineering, 1911
- Title
- Comparative tests on small steam pumps
- Creator
- Lewis, R. L., Monahan, J. E.
- Date
- 2009, 1908
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/comparativetests00lewi
Thesis (B.S.)--Armour Institute of Technology
- Title
- Comparative tests of small laminated and solid spruce beams for aeroplane construction
- Creator
- James, Sydney V
- Date
- 2009, 1911
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/comparativetests00jame
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 19
- Title
- Comparative test of cylinder lubricating oils
- Creator
- Hoffman, C. B., Jr, Hooper, B. G.
- Date
- 2009, 1907
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/comparativetesto00hoff
Thesis (B.S.)--Armour Institute of Technology
- Title
- The Engineering Significance of Limit Analysis
- Creator
- Hodge, Philip G. Jr.
- Date
- 2011-05-12, 1958-04
- Publisher
- Department of Mechanics, Illinois Institute of Technology
- Description
-
By definition, the limit load on a structure is the unique magnitude of the given loads under which a structure can first deform if it is made...
Show moreBy definition, the limit load on a structure is the unique magnitude of the given loads under which a structure can first deform if it is made of a rigid-perfectly plastic material. The significance of the limit load for a structure made of a real material is discussed in relation to a simple truss.
Sponsorship: Contract No. Nonr 140604
This research was sponsored by the federal government. The appropriate Department of Defense database, DTIC Online Access Controlled, was consulted prior to submission to confirm that the report has no distribution limitations and may therefore be made available to the public online.
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