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Full-Text Articles in Engineering
The Development Of Quiet Jet Engine Technology, Bradley D. Beck
The Development Of Quiet Jet Engine Technology, Bradley D. Beck
Retrospective Theses and Dissertations
The physical properties and subjective characteristics of sound and several special methods of measuring sound levels are discussed in order to provide a basic understanding of sound in general and noise in particular. The Federal Aviation Administration's regulation, FAR36, which stipulates the allowable perceived noise levels produced by commercial jet aircraft, is examined in detail. The principle of jet propulsion, the basic components of turbojet and turbofan engines, the theory of aerodynamic sound and the origin of the perceived noise decibel (which is the basic unit for measuring aircraft noise) are presented to provide an understanding of the fundamentals of …
A Passive Cooler For A Humid Climate, Steven Gilbert Ring
A Passive Cooler For A Humid Climate, Steven Gilbert Ring
Retrospective Theses and Dissertations
This paper examine a passive cooling system for a humid climate. This system will be divided into two parts, a radiative system and an evaporative system combined into a roof pond system. Performance of the radiative system will be enhanced through the use of a selective cover which will make use of an atmospheric window between 8 and 13um. An attempt will also be made to thermally isolate the radiative system from convective gains with the evaporative system. The evaporative system will consist of a water, solvent and dye layer over the selective cover of the radiative system. The performance …
The Application Of Limit Analysis To Shell Structures Using Existing Finite Element Analysis Codes, George G. Myers
The Application Of Limit Analysis To Shell Structures Using Existing Finite Element Analysis Codes, George G. Myers
Retrospective Theses and Dissertations
A ramjet inlet duct structure has been designed using nonlinear structural analysis to allow local plastic deformations which result in structural weight reduction. To establish the feasibility of reduced shell thickness, the Lower-Bound Theorem of limit analysis has been applied using an existing finite element analysis computer code intended for elastic analysis. The results of the analysis were verified by structural testing. Predicted stresses and deflections showed good correlation with measured values up to the point of failure. This work was supported by the U.S. Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohio, under Contract No. F33615-72-C-1366.
Nose Tip Recession Measuring System For Hypersonic Test Vehicles, James Anthony Brown
Nose Tip Recession Measuring System For Hypersonic Test Vehicles, James Anthony Brown
Retrospective Theses and Dissertations
A method is presented which permits the measure of nose tip recession of re-entry vehicles and advanced terminal interceptors by employing a double choked flow coolant gas system. Recession of the tip results in an increased exit flow area which reduces the total pressure of the gas in the blast tube. Measurement of the blast tube pressure and gas generator (chamber) pressure will produce an effective measurement of the nose tip recession as long as choked flow (i.e., sonic velocity) is maintained in both the tip exit area and the gas generator throat area. Governing flow equations documented in the …
Dynamic And Stability Characteristics Of An Articulated Frame Railway Passenger Truck, David Kenneth Platner
Dynamic And Stability Characteristics Of An Articulated Frame Railway Passenger Truck, David Kenneth Platner
Retrospective Theses and Dissertations
Mass transit vehicles in formal rail service frequently attain speeds which can excited carbody oscillations (primary hunting), as well as sustained lateral oscillations of the trucks (secondary hunting). The carbody motions have been shown to generate passenger discomfort and sustained truck hunting can lead to derailment. This thesis developed approximate equations which predict the carbody hunting frequencies, as well as the hunting speed of an articulated frame truck. The linear equations of motion are derived from a simplified model of a railway vehicle. A comparison indicates the results obtained using the approximate truck hunting equation presented here are within ten …