Sohaib A. Obeid
Department of Aeronautical and Mechanical
United state s
Sohaib A. Obeid is a researcher and a faculty member with the department of Aeronautical and Mechanical Engineering at a couple of worldwide institutions. His research interests include but not limited to aerospace and ground vehicle technology, Aero-acoustics, turbo-machines, reduced-order modeling, system identification and machine learning and mining techniques, analysis of nonlinear systems, and control designs for flow control problems.
He participated in many research projects and educational activities in Sudan, Ethiopia, Egypt, Iraq, France, Brazil, South Korea, and the United States. He authored a couple of articles, chapters in books, and one book.
My research interests are focused on aero-thermodynamics concepts, fluid-machines, and structural analysis. These topics have much in common with aeronautical and mechanical engineering, but their applications motivate different design choices. I used analytical, numerical and experimental facilities to investigate flow patterns over both 2D and 3D objects, static and dynamic behavior of structures and the fluid/solid interaction phenomena. My first research activity was in the eighties of the last century. I worked with a team from SNECMA “France” to develop a single spool gas turbine engine. I worked on both the compressor and the combustor sections. Then I focused on the detailed design of the first five stages of the axial compressor. This contribution widened my scope in research aspects, as I had the chance to learn how to validate analytical solutions and simulation results using experimental tools. Beyond all, I learned how to interpret physically my research results and plan to improve them.
Coupling the theory with the practice opens up a rich new application space in which results from many fields may be applied, including computational methods, modeling techniques, and measuring instruments. In my first master research, I studied the dynamic behavior of axial compressor blades; I developed a code to calculate the different modes of vibrations employing different approaches and validated my results with experimental works. I designed a test rig from the local available resources and implemented it to test compressor sections at first and then improved the design to inspect the whole gas turbine engine. I have found that using local available resources in carrying out research work might be a time consuming but would teach you how to think deeply to bypass obstacles within minimum effort and least price.
In the culmination of my first Ph.D. research, I developed a scramjet engine working at M=3.0. A detailed design of the individual components was carried out. Numerical simulations for the design point and offdesign points were conducted and finally a test model of the scramjet was inspected in the laboratory. Unfortunately, I couldn’t report all the results obtained during the lab testing because of the crisis held that that time. In my second master of research, I revisited the problem of sound field of point multipole sources in a linear shear layer. I figured out that sound waves passing through a shear layer are altered both in amplitude and direction. Hence, an observer situated in the far field on the opposite sides of a shear layer from a sound source will, in general, hear sound, which differs from that originally produced by the source. I studied the nature of the sound produced by an aircraft engine operation which passes a shear layer or combination of shear layers. I found that a thorough understanding of the aerodynamic noise by an aircraft engine in flight is essential for determining amplitudes of the far-field sound pressure. Such knowledge enables to develop an adequate correction techniques for data obtained from open-jet anechoic wind tunnels utilized for simulating the flight effects on noise sources.
In my second PhD research, I studied the problem of flow separation over flapped airfoils and wings. I developed numerical simulation models to study the flow physics around the wing and investigate the effects of synthetic jets on the flow separated regions. I developed reduced order models for the fluidic system employing two different methods. I designed closed loop control algorithms to reduce flow separation and enhance the lift generated. I have strong believes on that, through the development and study of new trends, I will characterize and abstract the new principles and primitives that enable the engineering sense to scale and flourish. In my vision, scientific research plays a vital role to explore the human gained skills rather than conventional examinations.
To date, I have authored or coauthored over 10 technical publications, including control designs for flow separation over airfoils. I peer-reviewed 4 journal articles. I plan to pursue my research activities in different areas and share my experiences with others. First, I plan to continue to minimize the gap between theory and practice by using modeling approaches. I have many contributions in Proper Orthogonal Decomposition (POD), Dynamic Mode Decomposition (DMD), Optimal Mode
Decomposition (OMD), Resolvent Analysis (RA). I work with regression techniques in system identification and machine learning problem. I have plans to focus on NARX and NARMAX approaches in system identification and pattern recognition. I dealt with neural networking in many projects in the past. I am planning to use this technique in a machine learning problem. My Ph.D. work explored the application of proper orthogonal decomposition and NARMAX identification methods to a specific application. After a few more applications exist, factoring out the right interface will be an interesting intellectual challenge. Second, I plan to study the impact of noise suppression techniques on the lifetime of structures, buildings, and humans being. Sometimes it is very hard to prevent the occurrence of the phenomena but it is more economic to delay it. On the other hand, the conversion of drawbacks and disadvantages into positive and useful topics represents a major challenge. As a rule, we should try our best to make use out of everything around us. By considering several distinct applications, I intend to learn more about how to implement scientific approaches while retaining sufficient generality for a broad range of applications. Third, I plan to consider some problems of human’s daily-life, living standards, and way of thinking that arises in urban and rural communities. Without some answer to these issues, it will be difficult for the researchers to positively contribute to the development of their communities. Spreading technical knowledge among students has favorable impacts on the industrial level and converts the attitude of people to be more productive and self-dependent.
Broadly speaking, I study the best ways to generate power, store power, and use it. I am specifically interested in wind power and its impact on long-term urban viability. Meanwhile, I hold great interest to deal with chemical lasers and implement them to operate different engines instead of conventional fuels. Many different ideas flash up to me every day and need to be employed and investigated using scientific approaches