John C. LaRue - US grants

The object of the research is to understand the structure and entrainment in combustion using a model laboratory complex flow with diagnostics having expanded capability. The approach employs existing two-color laser anemometry and thermocouple probes in combination with a fiber optic probe and laser spectroscopy in a series of experiments which model the characteristics of the complex flow and concludes with measurements in the complex flow itself. The fiber optic probe is included to assess the frequency response of the thermocouple probe. In addition, laser spectroscopy is used to further assess the validity of the temperature probes, extend the combustor operating condition under which temperature and heat flux measurements can be acquired, and provide for measurement of mass flux. The research delineates the effect of reaction and inlet conditions on the turbulent structure and entrainment of the flow. The study establishes an experimental data base that can be utilized in testing and developing mathematical models.

The objective of this work is the analysis and interpretation of observations of wind, temperature, and moisture from the atmosphere's boundary layer; the measurements were acquired at four sites over the past three years. The observations are perhaps the best taken in the past two decades and will be used to determine the turbulent energy budget in the boundary layer, the Kolmogoroff constants for temperature and velocity, and an independent determination of the von Karman constant. The behavior of the boundary layer is important to understand since it is capable of transporting water vapor, heat and momentum to the upper layers of the atmosphere, thus initiating or suppressing other meteorological developments throughout deep layers of the troposphere. Professor Friehe is well qualified to pursue the proposed work; he participated in all four experiments as well.

Non-intrusive Rayleigh scattering laser anemometry and a modular flow test facility are used systematically to explore turbulent transport and entrainment in a modular flow fixture that builds sequentially in geometrical complexity from a simple free jet to a complex flow reactor. Secondary goals address the evaluation of fine-wire thermocouple performance and the development of appropriate methods to obtain complete two-dimensional field information from sparse, point measurements. In the proposed work, the test matrix will be concluded with a study of the central jet surrounded by a swirling coannular jet, up to and including the complex flow model reactor. The program proposed is directed to an enhanced understanding of turbulent mixing in recirculating combusting flows, dominated by a high degree of swirl. The practical significance of the proposed research is that the flows selected for study are found in the majority of continuous combustion systems, such as gas turbine combustors, boilers, furnaces, and incinerators. The understanding of the turbulent mixing associated with these flows is timely in view of the growing restrictions in operation such as fuel consumption, emissions, noise, and fuel quality.

A two-component Laser Doppler Velocimeter (LDV) is acquired for a combined experimental and numerical study to enhance the basic understanding of the physics of two-way coupling between small spherical particles and turbulence. The two-way nonlinear coupling between particles and turbulence encompasses the dispersion of discrete particles due to the turbulent motion of the fluid, and the modulation of the turbulence structure by the motion on the particles. The primary goal of the experimental study is to simultaneously measure the instantaneous velocities of the fluid and particles in two directions and at two positions using a specially designed two-component LDV. The results obtained from direct numerical simulation will be compared with the experimental data, and used to test and improve available turbulence closure models of particle-laden flows.

The objective of the REU program at the University of California, Irvine, is to provide hands-on experience in active research to ten undergraduate students. The undergraduate students will conduct research in combustion and propulsion under the guidance of a supervising faculty member. A special attribute of the program is the close alliance of the research to 1) practical application, and 2) industrial collaboration. A second special feature of the program is the fostering of independence in research; the development of communication skills; the promotion of intuitive and innovative skills; experiences in budgeting, purchasing, and scheduling; and the development of accepting, adapting to, and resolving the challenges that arise in the conduct of research. The selection process is geared to promote the involvement of students of Chicano heritage and females.

The purpose of the proposed NSF Scholars Program at the University of California, Irvine, is to assist academically-talented, low-income third- and fourth-year undergraduates majoring in computer science, engineering, or mathematics to complete their baccalaureate degrees and to make a successful transition from college to work or graduate education. The two-year program will support 40 students a year with scholarships of $2,500 each. Scholarships will be linked to existing academic advising and other student-support services.

To be eligible, students must be juniors or seniors, enrolled full-time and majoring in computer science, engineering, or mathematics, who are eligible for Federal Pell Grants and have a minimum GPA of 2.75 (approximately the average GPA for these majors). Eligible students will be invited to submit a letter of application, which must contain evidence of interest and motivation, a description of career and graduate school interests, and an explanation of how the NSF scholarship would help them complete their degree. Scholars will be required to remain eligible each quarter and to meet regularly with their academic or faculty advisors.

An Orientation Meeting will be held at the beginning of each academic year to acquaint scholars with each other and the many academic and career-related services that are available to them, such as those provided by the following units: ?Undergraduate Research Opportunities Program (UROP) ?McNair/STAR Program ??Career Center ??Center for Opportunities and Diversity in Engineering (CODE) ??California Alliance for Minority Participation (CAMP) ??Student Academic Advancement Services (SAAS) ??Department of Information and Computer Science ??Schools of Engineering and Physical Sciences

Examples of such activities include resume writing and interviewing skills workshops, job fairs, faculty-mentored research opportunities, adjuncts for upper division courses, senior design projects with industry partners, industry roundtables, lunches with alumni and corporate representatives, information sessions presented by today's top technological firms, a graduate school prep course, and a Web-based resume book.

Two types of evaluations will be conducted: 1) a formative evaluation designed to provide constructive feedback for the improvement of the program, and 2) a summative evaluation designed to assess the overall success of the program. A student tracking system will be implemented to monitor the academic progress and graduation rates of the NSF Scholars, plus a similar, matched group of students who are not scholars selected at random from the eligibility pool. A variety of data collection methods, such as focus groups, interviews, and surveys, will be used. Students will continue to be tracked one year after graduation.