Program - - NSF S-STEM Scholar Program @ CSULA

NSF

CSULA - AERO INSTITUTE COOPERATIVE

NSF S-STEM @ California State University, Los Angeles

CSULA Aero Insititute

RESEARCH




Christian Dominguez

Comparing CFD with Combustion Capabilities NOx and CO2 Production to Physical Results in a Swirled-Air, Liquid-Fuel Combustion Chamber

With a grant from NASA administered through Dryden Flight Research Center (DFRC), the Multidisciplinary Flight Dynamics and Control Laboratory (MFDCLab) at California State University, Los Angeles has conducted research, both physical and virtual in the reduction of NOx and CO2 in the processes that occur in a simulated jet engine combustion chamber. A 2.7 ft long, swirled-air, liquid fuel combustion chamber was designed, constructed, and assembled. Kerosene, sprayed at 0.75 gallons per hour in the shape of a solid cone, at an angle of 30 degrees was used as the fuel and ambient air as the oxidizer. There are three air inlets: axial, tangential, and a secondary or dilution zone; all three combined produce airflow of 16.99 cubic feet per minute (cfm) maintaining a stoichiometric fuel to air ratio of 1. A stronger swirl, more tangential than axial air, and therefore a higher swirl number, has yielded a decrease in the production of NOx and CO2 (carbon dioxide) as well as physical solid particulate formation. Maintaining a constant fuel to air ratio is critical to obtaining results that do not depend on the addition of air but on a changing proportion of air from both the axial and tangential air ports. With a constant secondary air flow, manipulating both the tangential and axial flow rate varies the swirl number. A stronger swirl produces what is know as a flow reversal zone just after the fuel spray/diffuser inlet and aids in the mixture of the fuel and air. Also, a strong flame holding region is produced in and around this flow reversal area. This experiment will compare combustion products of NOx and CO2 from a physical model to those produced by the virtual model, in the context of simulating a jet engine combustion chamber and validating the software. The comparison between physical and CO2 emissions from the CFD is presented in the figure as well as swirl effect on flame.


Christopher Herwerth


Dynamic Response of a Proton Exchange Membrane Fuel Cell in an Uninhabited Air Vehicle

The use of PEM fuel cells to power uninhabited air vehicles is a relatively new application of fuel cell technology presenting several challenges with respect to fuel cell efficiency. When flight conditions warrant rapid increases in throttle settings, additional current is drawn from the fuel cell stack causing a voltage drop. The addition of a secondary power source such as a battery or capacitor can supplement the required power but must be configured and sized in a manner that justifies the additional weight and circuit components needed for their integration. A balance between maximizing power and electrical efficiency while minimizing weight and electrical losses requires careful analysis of a dynamic system. Considerations from the disciplines of thermodynamics, mechanical and electrical engineering design, chemistry and aerodynamics present an exciting challenge in development of fuel cell powered UAV’s.


Charles Chiang

Sang Bum Choi


Development of Fuel Cell Powered UAV for Long Endurance

In conjunction with Oklahoma State University, a long endurance Unmanned Aerial Vehicle (UAV) is being developed to break the world endurance record of 15 hours and 37 minutes. The electric motor and propeller propulsion system will be powered by a proton exchange membrane hydrogen fuel cell with assistance from lithium polymer batteries for extra power. The hydrogen will be stored in a high pressure tank. The main advantages of using fuel cells are its excellent power to weight ratio, efficiency, environmentally friendly, and as a replacement to internal combustion engines. The project will prove the advantages of using new alternative energy technology.


Matthew Walters



Development of Data Acquisition System for UAV testbed

Design and test LabVIEW measurement programs and the corresponding electronic circuits for tests conducted by the UAV team. The goal is to create useful tools that will expedite the process of designing a UAV. These measurement programs will be accessible to anyone working in the MFDC lab needing to quickly acquire data for analysis. The programs will automatically generate MS Office spreadsheet files that will then be able to be analyzed on any of the labs computers. The current data acquisition program under construction is for a fuel cell static prop test. The data to be acquired is voltage, current and temperature.


Alan Ko


Unmanned Aerial Vehicle Platform - Autopilot Integration

The term Unmanned Aerial Vehicle (UAV) is given to any aircraft that is capable of flying without a pilot onboard. Typically these vehicles are controlled via numerous ways ranging from a pilot in a ground-station, through pre-programmed flight plans, or with complex dynamic control systems. The applications of UAVs are wide and varied from target and decoy for military training, to reconnaissance missions in hostile situations, to civil missions such as search and rescue, firefighting and police operation. A need arises for the Multidisciplinary Flight Dynamics and Control Laboratory (MFDCLab) to become actively involved with UAV technology. The primary goal of the project is to create an UAV Platform that can be used as a learning tool for future MFDCLab members. The UAV platform is being developed in a three-phase process. The first phase includes the selection and built of an almost ready to fly (ARF) aircraft. The aircraft chosen was Tower Trainer 60 shown in Figure 1. The first phase also includes, the aerodynamic analysis of the aircraft, using hand calculations and computational fluid dynamic (CFD) code FLUENT and the first remotely piloted (RC) flight test. Figure 2 shows the mesh used for the CFD analysis. The second phase of the project involves hardware in the loop set up, development of our aircraft’s simulator, hardware in the loop simulations and a modified RC flight. Hardware in the loop (HIL) is needed to detect errors in the systems prior to flight and to program the autopilot. The autopilot being used for this project is Cloud Cap Technology’s Piccolo Plus, as shown in Figure 3. The complete HIL set up can be seen in Figure 4. The third and final phase will be adjustments of autopilot gains and ultimately autonomous flight.



PUBLICATIONS

2007

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  • College of Engineering, Computer Science, and Technology

  • California State University, Los Angeles