Mentor: Dr. Jacob Chung
College of Engineering
"I wanted to get more involved with work that is related to my major. I developed an interest in heat transfer and fluid dynamics during my first few years as an undergraduate. After taking heat transfer with Dr. Chung, he invited me to work in his research lab where I was able to utilize material I learned in class in a real world environment."
Mechanical and Aerospace Engineering
- Heat Transfer
- Fluid Dynamics
- University Scholars Program 2015-2016
- US Sugar Scholarship 2015-2016
Hobbies and Interests
Cryogenic Boiling Heat Transfer in Pipes and Liquid Acquisition Device Research
The research to be conducted in the department of Mechanical and Aerospace Engineering (MAE) during the 2015/2016 academic year will entail two coinciding parts: cryogenic boiling heat transfer in pipe flow and liquid acquisition device (LAD) research. Both projects are sponsored by NASA and closely related to the cryogenic community in order to solve problems with the transportation of cryogenic fluids from storage tanks through pipes and eventually into fuel tanks of space vehicles. The extension of human space exploration from a low earth orbit to a high earth orbit, then to Moon, Mars, and possibly asteroids and moons of other planets is one of NASA’s biggest challenges for the new millennium. Integral to this is the effective, affordable, and reliable supply of cryogenic fluids. The efficient and safe utilization of cryogenic fluids in thermal management, power and propulsion, and life support systems of a spacecraft during space missions involves the transport, handling, and storage of these fluids in terrestrial and reduced gravity. The uncertainties about the flow pattern and heat transfer characteristics pose a severe design concern. Therefore, the design of cryogenic fluid storage and transfer system is very important and spawns research in several areas: for example, design of the vessel, the piping and draining system, insulation and safety devices. Moreover, the thermo fluid dynamics of two phase systems in reduced gravity encompasses a wide range of complex phenomena that are not understood sufficiently for engineering design to proceed. The cryogenic pipe flow and heat transfer research will look to provide proper correlations needed to aid designers of cryogenic fluid transportation systems. During pipe chill down process, cryogenic fluid will boil very quickly in a pipe that is very hot compared to the fluid temperature, such as a pipe at room temperature. It is not until the pipe is brought down to a temperature that single phase cryogenic liquid, such as liquid hydrogen or liquid oxygen, can flow through the pipe with minimal losses to vaporization. With the price of liquid hydrogen currently at around $15,000 per kilogram, it is vital the designers know exactly how much losses to expect when transporting the fluid. The current research in this field involves over simplified models of the problem and does not provide adequate correlations useful to design due to such high errors. The purpose of this research is to provide universal correlations for pipe chill down in a stainless steel pipe during cryogenic fluid transport in a pipe. The research will look to provide information about pipe wall temperature, heat transfer rate, and heat transfer coefficients during the various boiling stages that occur in two phase cryogenic pipe flow. This information will be very useful in amending the current computer codes that try to simulate this kind of pipe flow. The LAD research project is focused on the separation of cryogenic liquid from vapor in storage tanks in space conditions in order to have them piped away to the vessel in need of fuel. A widely used LAD involves the usage of a very fine but porous screen in order to allow only liquid to flow through it holding the vapor back with the surface tension of the liquid. An important tool in developing this technology is computational fluid dynamics (CFD) software to simulate the storage transfer process. Research has been done in the past on this problem, but three major phenomena have been ignored: the effect of cryogenic temperatures on the screen, the slip velocity at the screen, and the effect on the pressure drop due to exposing the screen partially to vapor. This experiment will only address two of the neglected phenomena: slip velocity at the screen and exposing the screen partially to vapor. The experiment will look to capture data on the pressure variation along the screen lengthwise and the velocity profile along the screen length and widthwise. The pressure will be measured using differential pressure transducers (DPTs) while the velocity will be measured using dye injection and a camera in order to visualize the flow field. The data obtained from this experiment will allow for efficient and accurate CFD simulations for flow out of a storage tank using LADs with mesh screens. This will be important to NASA as future deep space missions, i.e. a human trip to Mars, will require a large amount of propellant and extraterrestrial refueling in order to reduce transit time. Both of these research projects will play a huge role in space travel. The technologies developed in this lab will allow for efficient propellant transfer with minimal waste. With NASA planning to develop extraterrestrial fuel depots in the future, the need for proper correlations of this phenomena has never been greater. On a personal note, I am truly excited to explore these technologies in UF’s cryogenic research lab led by Dr. Jacob Chung and help provide the information that NASA and the cryogenic community needs.