This book addresses the key concepts of self-healing processes, from their occurrences in nature through to recent advances in academic and industrial research. It includes a detailed description and explanation of a wide range of materials and applications such as polymeric, an…
A very interesting aspect of the axisymmetric jet is the existence of azimuthal instability modes. Since all low order modes are unstable near the nozzle exit plane, a wide variety of modes are susceptible to external excitation. If known resonance conditions are satisfied, nume…
Base flow characteristics are very important for determination of drag in aircraft propulsive systems. Since the performance of these systems must be known before actual production, and it is very costly to build and test every system in order to select the best design, a comput…
A thermomechanical description of the martensitic phase transformation and the associated shape memory effect in polycrystalline shape memory alloys (SMAs) is presented. The rate-independent constitutive relations are derived in the stress-temperature space using a Lagrangian fo…
A parallel approach to the solution of a turbulent flow problem was developed. Our approach was highly parallelized. Two-dimensional channel flow at known and unknown pressure gradient was studied. The study was divided into two phases. In phase one, fully developed channel flow…
Economic considerations have forced users of commercial jet transports to retain the services of aircraft that have surpassed the designed lifetime of structural components of the aircraft. With the increased service time that these aircraft are experiencing, many of the aircraf…
This work studies optimized controls which minimize the heat load at the stagnation point of an ascending hypersonic flight vehicle. Two types control schemes are studied, namely, a polynomial type of feedback controller and a neural controller. To validate the results obtained …
Since probe theory was developed, the problem of current collection by a charged spherically or cylindrically symmetric body has been investigated by a number of authors (e.g. Parker and Murphy, 1967; Linson, 1969; Laframboise and Rubinstein, 1976). The purpose of this paper is …
Nonlinear mechanics, and specifically geometric nonlinear mechanics, is still an emerging field. The objective of the research effort reported in this document was to develop a finite element code using a refined definition of the curvature of an inplane beam. The general nonlin…
Centrifugal fans are rotodynamic machines used for moving air continuously against moderate pressures through ventilation and air conditioning systems. There are five major topics presented in this thesis: (1) analysis of the fan scaling laws and consequences of dynamic similari…
A stochastic model for the accumulation of fatigue damage in composite laminates is proposed. The model considers the accumulation of fatigue damage as an evolutionary stochastic process and attempts to predict the distribution of damage in terms of the stiffness loss in the lam…
An experimental study was undertaken to elucidate the mixing enhancement and noise reduction in a jet caused by tabs, simple protrusions into the flow, placed at the nozzle exit. Far-field acoustic spectra of underexpanded jets showed the elimination of screech and a decrease in…
This thesis examines the dynamic instability known as flutter using a two-degree-of-freedom airfoil section model in both quasi-steady and unsteady flow. It explains the fundamental forces and moments involved in the bending-torsion flutter of an airfoil section, and demonstrate…
The full Navier-Stokes equations were employed with a single-fluid model and a front tracking scheme to study large cylindrical, spherical, and ellipsoidal bubbles in a free shear layer. This approach allows direct simulation of the multiphase flow by wholly incorporating the bu…
The control of boundary layer is very important in the field of aerodynamics and hydrodynamics and becomes essential for current wing design technology to increase lift, stalling angle of attack and lift-to-drag ratio. Therefore, an experimental investigation has been conducted …
Future space systems such as Space Station Freedom, and space defense systems will require storage of cryogenic fluids in a low-gravity environment for extended periods of time. Heat leaks to the containment vessel lead to an increase in the temperature and pressure of the fluid…
The problem of flutter is first introduced. The equations of motion of an airfoil with two degrees of freedom, in pitch and plunge, are obtained. Then, the unsteady aerodynamic theories for different flow regimes are presented. The traditional solutions to the flutter problem, n…
Numerical simulation of flow past airfoils is important in the aerodynamic design of aircraft wings and turbomachinery components. These lifting devices often attain optimum performance at the condition of onset of separation. Therefore separation phenomena must be included if t…
Results from two distinct investigations are reported in this dissertation. In the first investigation, linearized stability analyses were performed to investigate effects of Marangoni stresses on hydrodynamic stability of bi-component droplets slowly evaporating in a sphericall…