[:en]Ms. Mikiko Iwago
Hometown in Japan: Kanagawa
Home University in Japan: Tokyo University of Science
Major & School Year: Mechanical Engineering, B4
Research Host at Rice: Prof. Tayfun Tezduyar, Mechanical Engineering
Research Project Title: Moving-­Mesh Method for Ice Crystal Icing Simulation (PDF)

Why TOMODACHI STEM @ Rice University?
TOMODACHI STEM provides chance to have many fruitful discussions with inspirational people who are now engaged in STEM and would be my role models, mentors and friends, which are exactly aligned with my studies and professional development.

Goals

• Personal goal is to feel the atmosphere around female engineers and researchers and have active exchange of opinions about it.
• Language goal is to hang in there even if I could not tell my thought in English.
• Research goal is to learn four numerical methods to apply to my research.

Questions I have About Research or Life in the U.S. – Prior to Departure

1. How do you work together with other researchers?
2. How do academic researchers collaborate with government and industry on the research and the development?
3. How are science and engineering (researchers) familiar for the public?

Excerpts from Mikiko’s Weekly Reports

• Week 01: Arrival in the U.S.
• Week 02: Critical Incident Analysis
• Week 03: Research in the U.S. vs. Research in Japan
• Week 04: Research Project Presentation
• Week 05: Final Week at Rice University
• Week 06: Science & Technology Policy Study Tour in Washington, DC
• Final Report

Week 01: Arrival in the U.S.

I was surprised that there were many foreign students in campus especially Chinese and Indian. I had imagined that there would be many American students in the university in the United States but the scenery was totally different. Actually, my host laboratory has 4 Chinese, 1 Turkish and 1 American student.

But this situation made me more excited because this was the chance to put myself into the environment of “diversity” and have fruitful discussions with foreign students, which is one of reason why I had been interested in this program.

On the third day, we had a chance to meet with President David Leebron. I asked him, “How can we collaborate with Rice students?” Looking ahead to the future of our generation, he proposed some ideas which use existing aspects of world’s history, culture and STEM in each country. The phase “Think Globally, Act Locally” came back to me.

His ideas are quite helpful to imagine “what different perspective Rice students bring for me” and “how I can share my knowledge and experience with Rice students”. I came to look forward to discuss and talk with Rice students more and more.

Question of the Week?
Why did Rice students decide to enter Rice University? Through this question, I will also be able to know that why there were many foreign students in the university in the U.S.

First Day in the Lab
Actually, I met my host professor last December in Tokyo. Ever since first met in Tokyo, we kept in touch with each other and he gave me some assignments in advance. The assignments were to read his book and notes of his Advanced Computational Mechanics class. So we confirmed how deeply I understand and what we can do for this 4-week intensive period. After the meeting, I continue to read and understand the contents of his book and notes.

Research Project Overview
Research Host at Rice: Prof. Tayfun Tezduyar, Mechanical Engineering

Description: When aircraft fly into clouds, a lot of ice crystals are ingested into the warm engines where they melt and adhere to the surface of the stators. This phenomenon is called “Ice Crystal Icing” and causes engine damage and power loss. Although it remains a serious hazard in aviation, little is known about the mechanism.

So I want to create a precise numerical model of the ice crystal icing process in order to know what these ice crystals look like in the air, how they behave, how they melt and how they adhere to the surface of the stators.

I regard moving-mesh methods, mesh-adaptation-based approach, as practical and effective for that, however I haven’t thought about how the methods can work for my research. My objective of this research internship is to understand the overview of mesh moving, make the strategy of my research and apply the mesh moving method to the first step of my research under Prof. Tezduyar direction.

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Week 02: Critical Incident Analysis

After deciding to participate in this program, it was decided that two undergrad students who were taking Prof. Tezduyar’s class would also come to Japan to a do two and a half months research internship in my home laboratory. So this week I met them for the first time and we had lunch together so I could give them an overview of Japanese life and my laboratory.

Then they repeatedly asked me about my previous learning. At first, I thought that they are simply highly motivated students. However, as we talked, I became to think that it’s just for only one reason. I have approximately two other reasons in my mind. One is cares and anxieties weight on them. I have heard before that doing internship is popular among undergrad students in the U.S. Before I knew that, I was confused to be popular to and to be used to do internship. Then I could understand and thought it is natural that they have some anxieties for internship.

Another is that people in the U.S. view internship as important. In Japan, doing internship is less important than in the U.S especially in STEM fields. I guess that it is related to the job hunting system.

Question of the Week?
So I would like to know about the relationship between internship and job hunting system in the U.S.?

• Many U.S. college students want to do a summer internship or part-time job with a company in their desired field of employment as a way make their resume more competitive to a potential employer when looking for jobs after graduating from their bachelor’s degree. However, it is not required and students can apply for any job with any company after they graduate even if they have not done an internship with that company first or have no prior experience in the field. Hiring is done by each company as needed and when they have jobs available. There is no set hiring or interview time-table like in Japan, though many companies do seek to recruit graduating students in the fall or spring semester of their final year of study.  Some students do not find a job until after they have graduated and may continue to work a part-time job or live at home until they find a full-time job in their chosen career field.
• All universities in the U.S. have career centers, such as the Rice Center for Career Development, that provide job and internship search and support services including a database where employers who want to hire Rice students can list opportunities.  They also arrange career and internship fairs on campus. They also offer a wide range of student resources that can be helpful for college students seeking to apply for internships or jobs. Career center services are open to undergraduates, graduate students, international students and alumni of that university so even after graduating from Rice University, for example, students can still utilize the career website to look for or find jobs.

Research Project Overview

This week, we made a plan for how our work would progress through daily discussion with my professor.  Here is what was decided:

Topic:

1. CFD basis (finite element)
2. CFD application (moving mesh)

Tools:

1. Book written by Prof. Tezduyar
2. Prof. Tezduyar’s class materials
3. Prof. Tezduyar’s slides about moving mesh

2/29

• 3 hour discussion with Prof. Tezduyar
• self-learning

1. CFD basis (finite element)
   • Finite difference
   • Finite element

2. CFD application (moving mesh)

• mesh update (moving mesh & remeshing)
• special- / general-purpose mesh moving

3/1

• 5 hour discussion with Prof. Tezduyar
• self-learning

1. CFD basis (finite element)

• introduction of finite element

By comparing partial differential equation with integrated residual of the differential equation, we can find 2 problems.

Firstly, we don’t have b.c. on the nodes with unknown solution coefficients. To detect the unknown solution coefficients, we need the same number of equations. By using weighting function, we can achieve it.

Secondary, we have second derivative in the residual equation. By partially integrating, we can express it by first derivative.

Thus, we can gain the finite element equation.

2. CFD application (moving mesh)
   1. FEM will work on any grid (i.e. Grid lines do not need to be perpendicular) but will lose accuracy if mesh is too disturbed. So we need to do something to keep the mesh shape good.
   2. The most important thing for moving mesh is to keep the mesh resolution nearby the surface of the thing (like airfoil) approximately constant but it needs some techniques. So it is why we mainly focus on the moving mesh.

3/2

• 1 hour discussion with Prof. Tezduyar
• self-learning

2. Application of CFD (moving mesh)
   1. We discussed why Jacobian-Based Stiffing make the mesh shape good by  holding up finite element formulation of linear elasticity equations as an example

3/3

• 1 hour discussion with Prof. Tezduyar
• self-learning
• Interface tracking and interface capturing
• Boundary Condition of free surface (mesh-moving velocity = fluid velocity)
• Reading thesis of moving-mesh method

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Week 03: Research in the U.S. vs. Research in Japan

On numerical approach, it is important to understand studies using numerical approach, it is very important to understand theories. Before my experience here, I thought that books and papers are the only tool to understand those theories so research is an individual application of the theories you have learned.

However, here in my lab, I have daily discussion sessions with my professor and seniors who have helped me to understand difficult theories by showing their research results. So I could feel that research is not individual endeavor, but team effort.

All students in my laboratory attend our professor’s class, the Advanced Computational Mechanics, twice a week. In Japan, professors often say “If you have any questions, please feel free to ask anytime. It is important to do this class interactively.” So I thought that an “interactive class” is a class where the professors lecture without asking questions and the students ask questions, and the professors answer those questions.

But in the U.S., especially in the class I took, the professor asked the students a lot of questions, and the students answered those questions. Whatever he asked, they gave him some kind of answer. More importantly, the student next to me always whispered his answers. Maybe other students also whispered their answer in their heads.

Then I thought that a truly “interactive” class would be like this. This experience was helpful for me to think about how I could have meaningful discussions in class.

Practical, conceptual and theoretical understanding is valued in my research lab in the U.S. On the other hand, writing many papers is valued in Japan.

Question of the Week?
I was interested in the reason why there is so many Chinese in campus. So I asked Chinese students. They replied that most of Chinese in campus would be graduate students. Although there are some reasons why they are here, the passion to continue their research and need money would be two main reasons. I thought it is the meeting of the supply and demand.

• Yes, there are many international students at Rice University, particularly graduate students.  For more on this see the Rice Office of International Students and Scholars Statistics Report that they update each year.
• International student enrollment varies by university, but especially in science and engineering graduate degree programs it is quite high. For more data on nationwide international student enrollments see the Institute of International Education’s Open Doors report.

Research Project Overview

3/7

• 1 hour discussion with Prof. Tezduyar
• self-learning

Discussion Topic: Interpolation

There are two options for Interpolation.

1) Mesh moving

We can detect how much the nodes moved by using interpolation and known B.C. For finite difference method, we call interpolation as smoothing.

2) Projection

From the old mesh to the new mesh. (e.g. least-squares projection)

Regarding of the way of searching the new nodes.

3/8, 3/9

• self-learning
• I organized my research and what I learned
• I asked my home professor questions to confirm the direction of my research, and my home professor replied to my questions

I am now struggling about how to search the new nodes and projection. Moving mesh can be used for both the melting process and the icing process. I made the strategy of the mesh update. The calculation cost is not large because we can start the calculation until front of the wing, not engine inlet. For the icing process, we use moving mesh and renoding.

Renoding is needed for 2 reasons. One is the nodes would slide on the wall when the particle touches to the wall. Another is this. When we assume that the wall is covered with liquid, we need to put the mesh between the particle and the wall. As the particle is getting closer to the wall, the mesh would be squeezed. So we need to remesh (renode) and decrease the mesh resolution. How we can remesh would be the key point of your research.

3/10

• 1 hour discussion with Prof. Tezduyar
• self-learning

Based on yesterday brain storming, I asked Prof. Tezduyar questions about more practical details of moving-mesh method.

3/11

• self-learning
• learn practical example with senior

In the morning, I made the strategy for simulating ice crystal icing. In the afternoon, I worked with my senior to learn how to put the mesh-moving theory into practice by using research results of him.

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Week 04: Final Week at Rice University

Report not yet submitted

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Final Research Project Presentation

On Friday, March 18 all TOMODACHI STEM students gave a research project presentation at Rice University. To see a PDF of the student’s presentation, click on the research project title below.

Research Host at Rice
Prof. Tayfun Tezduyar, Mechanical Engineering

Research Project Title
Moving-­Mesh Method for Ice Crystal Icing Simulation (PDF)

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Week 05: Science & Technology Policy Study Tour in Washington, DC

This week, I reviewed what I learned through this research internship. On Monday, I made a strategy to apply what I learned in Rice Laboratory to my research. On Tuesday and Wednesday, I solved my questions one by one, by reading books and thesis and asking supervisors and seniors. The process of making a material for the final presentation made it clearly that what I don’t know and what I don’t understand.

Additionally, Lab. members came to ask me “When will the final presentation be held?”, “What kind of subject?”, “In what way?”, “Are you ready?” and “If you want to use some materials related to moving mesh, please ask me.” and “If you want to practice aloud, you can use other room.”. Although I stayed only one month, they gave me kind words and supports. They were considerable and solicitous, and then I thought I wanted to be like them.

In Japan, there are few foreign students in my laboratory so there is Japanese domestic environment. Therefore, I imagined that there would be American domestic environment in my host laboratory. However, the environment was totally different. Rice was the platform for people who really want to enhance their capabilities to contribute to the society and people regardless of nationality.

They just devoted their research genuinely. The scene was so impressed on me and reminded me like “I really wanted to be an engineer”. However, they had diverse future career goals not only to be an engineer but also a pilot, a financier and so on. The fact was more impressed on me.

After entering my college, whenever asked what I wanted to become, I answered “I want to be an engineer.” For some reason, I thought of the professionals of engineering and working as an engineer. I never doubted what it meant to be a student of engineering according to society’s definition. From the time we enter the department of engineering, our future is decided in Japan. On the other hand, in the United States, the future of the student is more flexible than Japan. The culture was attractive for me.

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