Engineering Commons^™

The Effects Of Asymmetric Micro Ratchets On Pool Boiling Performance, Lance Austin Brumfield

LSU Doctoral Dissertations

Nucleate boiling is an attractive method for achieving high heat flux at low superheat temperatures. It is frequently used for industrial applications such as heat exchangers and is being considered to cool advanced central processing units (CPU) which produce heat fluxes on the order of 1 MW/m2 and are becoming increasingly less efficient to cool via forced conduction of air. The issue with implementing nucleate boiling as a cooling mechanism lies in the difficulty of quantifying the numerous and complex mechanisms which control the process. A comprehensive nucleate boiling model has yet to be formulated and will be required in …

Dynamic Characterization Of Vocal Fold Virbrations, Zhenyi Wei

LSU Doctoral Dissertations

An emerging trend among voice specialists is the use of quantitative protocols for the diagnosis and treatment of voice disorders. Vocal fold vibrations are directly related to voice quality. This research is devoted to providing an objective means of characterizing these vibrations. Our goal is to develop a dynamic model of vocal fold vibration, and map the parameter space of the model to a class of voice disorders; thus, furthering the assessment and diagnosis of voice disorder in clinical settings.

To this end, this dissertation introduces a new seven-mass biomechanical model for the vibration of vocal folds. The model is …

The Spectral Conforming Model And Its Applications, Jaeho Shim

LSU Doctoral Dissertations

It has been observed that finite element or finite difference model of order can approximate with fair accuracy less than one-third of the eigenvalues of the underlying continuous system corresponding to the low spectrum. The new discrete model, namely the spectral conforming model, is developed to predict the eigenvalues of continuous systems in both the low and high spectra. The spectral conforming models are developed using an inverse vibration method. The classical vibration problem is the direct method. In the direct approach, the characteristic behaviors of the system, i.e. frequency response, natural frequency, and steady state response are analyzed and …