Week 6

The project I'm working on is an inverted liquid piston air compressor. This differs from an ordinary air compressor in that the piston itself is stationary while the compressor walls and top cap move up and down for compression/expansion. Because the piston is stationary, I'm able to add a column of water on top of it. Based on previous research, this type of air compressor will have increased heat transfer - in part because the water absorbs some of the heat from the air and can be recirculated through a heat exchanger, and in part because this configuration allows porous media to be added and thus further increase surface area available for heat transfer. Increasing heat transfer is important because it means better compressor efficiency!

My work is focused on the stability of the interface between the water and the air. This involves changing the operating frequency, compression ratio, and porous media geometry as well as observing the effects of adding hydrophobic coating to the porous media and adding water recirculation. Thus, this work has involved hands on testing, setting up the recirculation circuit, modeling porous media, data analysis, and background research to better understand the related research and the interface behaviors I'm observing.

The target market for this air compressor will be based on the operation parameters with "nice" interface stability (ie the findings of my work). The goal, though, is to use this air compressor in a Compressed Air Energy Storage (CAES) system. In CAES, excess energy is used to power an air compressor, which compresses air to a high pressure. This compressed air is then stored in a tank and can be expanded through a turbine when energy demand increases. Thus, this technology would be a great way to implement intermittent renewable energy technologies, like wind and solar power, because excess energy can be stored for later use!

Week 3: Better Late Than Never

*title credit goes to Diana Luc

The biggest difference I've noticed between working in a research lab and working at an internship is the amount of flexibility because I'm able to set my own hours. Furthermore, research is much more self-directed and creative than most internships - while the overarching problem I'm trying to solve is relatively defined, the technology has never been done before. My professor and I discuss the behaviors we're seeing and the overall goal, but he often leaves the next steps to be decided by me. It's been a great challenge to figure out what aspects of the project are the most pressing and make the most sense to figure out first and determine the most cost-effective, quickest, and robust way to complete next steps. At the same time, this process has allowed me to utilize my research strengths, develop skills, and increase my self-awareness. The lab itself is split into work stations and projects, with usually one graduate student or serious undergraduate tackling each project. All of our work falls under the umbrella of fluid power, but it's been exciting to learn more about the diverse challenges of the fields at our weekly presentation meetings.

Week 3: Picking up the pace

My impression of the environment in my laboratory compared to what I actually thought was going to occur is that it is substantially more relaxing. Here at the lab I have more freedom than I thought I would be granted. My PI has structured the lab in a way that allows you to work your own schedule, and get things done at your own pace. Even though this environment seems great, if you aren't well structured it easy to lose yourself. Luckily for me in the lab I'm working with a post-doc and a masters student. They have been mentoring me throughout my time here since my PI has been traveling throughout the summer so he hasn't been around the lab much. They've helped me out in terms of helping set milestones so I wouldn't feel overwhelmed with my project. What has surprised me is the fact that working in this lab I have access to so many resources in terms of machines for machining your own parts. We also have our own 3-D printer, and access to water jet cutters, along with laser cutters. What's positive about my research environment is that whenever I run into a problem there's always someone I can reach out for help. What's not so great is that sometimes there's things that nobody can help me with because it is outside their knowledge. 

- Keep working hard people!!

Trial and error exoskeleton designs

Hey everybody,

As I have written in previous posts, my project's goal is to design a wearable exoskeleton-like device that will support the worker's hands weight in order to limit neck injuries and musculoskeletal disorders (MSDs). My project is brand new (I am the first researcher to work on it) thus I started the first couple of days doing some literature research on papers that study MSDs. After studying some demographics that address the problem, I figured out that for occupational MSDs the biggest cause is overexertion of arms to loads and awkward upper body posture. So the solution to that would be an exoskeleton that will support the upper extremes. We are definitely looking on implement fluid power on our project as the pneumatic pistons force outcome is very good for not much weight. We need our design to be as lightweight as it can because worker will have to carry it.
For now though, these past four weeks I've been spending my time on Solidworks designing different types and ideas for exoskeletons, in order to decide which fits best our application. We want the design to be easy to wear, lightweight, and to not put constraints on the arms movement while the same time it has to cancel out the weight of the had itself and possibly any tools the worker is holding. I've 3-D printed a couple of small-scale designs so I can see how the move in real world because I thought Solidworks assembly movement software is not very realistic. After printing some designs I decided on the best one which I will focus more on. The most difficult part of my research until now is the fact that it is a lot of trial and error process where I have to come up with my own ideas of new designs. Another thing that is part of research but may seem annoying is that many times you spend a lot of time on something that may not even work or be needed, which ofcourse you don't know.

I hope your research is going well too,

Spyros Kasapis

Week 6: Cylinder Cushion Test Stand

Hey everyone,

The project I am part of at Iowa State University is about making hydraulic systems more precise and accurate. Hydraulic cylinder cushions decelerate cylinders piston and rod assemblies at the end of the stroke. The commonly-used design process used to determine the cushion geometry involves trial and error with physical components and thus requires substantial costs and time. To address these limitations, a cylinder cushion model was developed to enable virtual prototyping of cylinder cushions. To validate the models, a test stand was designed and built with a hydraulic cylinder containing a cushion. To test cushion model effectiveness in estimating the cushion response, large forces were applied to the cylinder when retracting and approaching the end of stroke. The force was a summation of weights on top and pressurized fluid provided by an accumulator to the cylinder rod end. 

Results from this apparatus will be used to revise and improve the computer models. It is exciting to know that whatever we learn through this research can impact the hydraulic industry for better motion control. With this, fluid power and hydraulics will be able to boast high power density with precise movements.

Hope you guys are doing well as we move into the second half of our program.

- Seong  

Research Environment at UMN

Hey everyone,

I just thought I'd comment on my experience at the University of Minnesota so far.

Throughout this summer, I have worked on a testing platform for a novel variable displacement pump/motor. I work alone, and I don't share a lab with other graduate students or other undergraduates. In some respects, this is positive in that I have a great deal of independence; I have the ability to determine my own working schedule and I have had opportunities to practice problem solving through tinkering and independent study. However, this independence comes with some disadvantages as it can be difficult to stay motivated and on task with no one around to boost morale, and the work can become monotonous.

Compared to my previous experiences in a large state school, UMN seems somewhat empty during the summer and as a result I haven't had an opportunity to get a real sense of the research culture here. I can say that it has been a pleasure to work with my faculty advisors as they are very upbeat, excited about their work, and eager to help wherever they can.

Hope everyone is enjoying their summers,
Mike

Research Culture at University of Minnesota

I was pretty scared before coming into my research lab. I thought they would be pretty strict and have a schedule for when everything needs to be done. Surprisingly, my research lab starts around 9:30/10 even coming in later sometimes. It has been pretty laid back. There's no set schedule but more of a going with the flow type of environment. The first couple weeks here have been extremely chill for me which surprised me because I thought I'd be working hard all the time. I didn't expect the amount of freedom I get by doing research. My graduate student doesn't really tell me what to do rather I get to come up with how I approach my project which is kind of cool to do even if it doesn't work at first. It all makes sense now why research takes so long because no one's ever sure of what they're doing. 

-Diana