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Full-Text Articles in Engineering
Determination Of Acoustic Radiation Efficiency Via Particle Velocity Sensor With Applications, Steven Conner Campbell
Determination Of Acoustic Radiation Efficiency Via Particle Velocity Sensor With Applications, Steven Conner Campbell
Theses and Dissertations--Mechanical Engineering
Acoustic radiation efficiency is defined as the ratio of sound power radiated to the surface vibration power of a piston with equivalent surface area. It has been shown that the radiation efficiency is maximized and may exceed unity when the structural and acoustic wavelengths are approximately equal. The frequency at which this occurs is called the critical frequency and can be shifted with structural modifications. This has proven to be an effective way to reduce noise. The standard radiation efficiency measurement is comprised of an intensity scan for sound power measurement and accelerometer array for spatially averaged vibration determination. This …
Development Of A Muffler Insertion Loss Flow Rig, Jonathan Chen
Development Of A Muffler Insertion Loss Flow Rig, Jonathan Chen
Theses and Dissertations--Mechanical Engineering
Mufflers and silencers are commonly used to attenuate noise sources such as internal combustion engines and HVAC systems. Typically, these environments contain mean flow that can affect the acoustic properties of the muffler components and may produce flow generated noise. To characterize the muffler performance, common metrics such as insertion and transmission loss and noise reduction are used in industry. Though transmission loss without flow is often measured and is a relatively simple bench top experiment and useful for model validation purposes, mean flow can significantly affect the muffler performance. There are a few existing and commercial transmission loss rigs …
The Effects Of System Characteristics, Reference Command, And Command-Following Objectives On Human-In-The-Loop Control Behavior, Seyyedalireza Seyyedmousavi
The Effects Of System Characteristics, Reference Command, And Command-Following Objectives On Human-In-The-Loop Control Behavior, Seyyedalireza Seyyedmousavi
Theses and Dissertations--Mechanical Engineering
Humans learn to interact with many complex physical systems. For example, humans learn to fly aircraft, operate drones, and drive automobiles. We present results from human-in-the-loop (HITL) experiments, where human subjects interact with dynamic systems while performing command-following tasks multiple times over a one-week period. We use a new subsystem identification (SSID) algorithm to estimate the control strategies (feedforward, feedforward delay, feedback, and feedback delay) that human subjects use during their trials. We use experimental and SSID results to examine the effects of system characteristics (e.g., system zeros, relative degree, system order, phase lag, time delay), reference command, and command-following …