Solving Problems

02/24/17

This post is going to be addressing my post on February 16 regarding the problems that I encountered while building the wind tunnel.

I realized the cardboard rolls where not the issue, but it was the placement of them which really messed it up. I tried to place them slanted inside the cone part when I could of just placed them in my flow straightener part which is more or less a square. It being a square made it easy for me to line them up making the wind tunnel more stabilized as well.

I hope the visual makes it easier for you guys to understand where those cardboard rolls are located now. I previously had them in the cone part making it slanted which caused the issues. They are now in this part of the wind tunnel making it easier for me to duct tape them together. I also got stronger duct tape which helped a lot. I just have to close this part up and start working on the viewing and diffuser sections of the wind tunnel. Once this is complete, my on-site adviser and I will start to work on the real model wind tunnel which will look a lot better than this one. We will use this wind tunnel as a layout as we are also going to be testing how well this layout works by putting a fan in it. The fan should be able to point out any structural mistakes, but its mostly to see if you can view what we are testing and how it is being affected by the wind as that is the main point of a wind tunnel. If this does not work, then lets just say we would have to start all over again with a fresh and better design. If we have to start over again then we would just start to build the real wind tunnel and ignore building another prototype. I mean we would have to be more careful as we can't mess up this time as its the real deal now. 

Types of Wind Tunnels

02/21/17

Wind tunnels can be classified based on airflow speed in test section and based on shape.

Based on Flow Speed:

1. Subsonic or low speed wind tunnels:

Maximum flow speed in this type of wind tunnels can be 135m/s. Flow speed in wind tunnels is generally preferred in terms of Mach number which comes out to be around 0.4 for this case. This type of wind tunnels are most cost effective due to the simplicity of the design and low wind speed. Generally low speed wind tunnels are found in schools and universities because of low budget.

2. Transonic wind tunnels:

Maximum velocity in test section of transonic wind tunnels can reach up to speed of sound ie 340m/s or Mach number of 1. These wind tunnels are very common in aircraft industry as most aircrafts operate around this speed.

3. Supersonic wind tunnels:

Velocity of air in test section of such wind tunnels can be up to Mach 5. This is accomplished using convergent - divergent nozzles. Power requirements for such wind tunnels are very high.

4. Hypersonic wind tunnels:

Wind velocity in test section of such type of wind tunnels can measure between Mach 5 and Mach 15. This is also achieved using convergent - divergent nozzles.

Based on Shape:

1. Open circuit wind tunnel:

This type of wind tunnel is open at both ends. The chances of dirt particles entering with air are more so more honeycombs (mesh to clean incoming air) are required to clean the air. Open type wind tunnels can further be divided into two categories:

a) Suckdown tunnel: With the inlet open to atmosphere, axial fan or centrifugal blower is installed after test section. This type of wind tunnels are not preferred because incoming air enters with significant swirl.

b) Blower tunnel: A blower is installed at the inlet of wind tunnel which throws the air into wind tunnel. swirl is a problem in this case as well but blower tunnels are much less sensitive to it.

2. Closed circuit wind tunnel:

Outlet of such wind tunnel is connected to inlet so the same air circulates in the system in a regulated way. The chances of dirt entering the system are also very low. closed wind tunnels have more uniform flow than open type. This is usually a choice for large wind tunnels as these are more costly than open type wind tunnels.

Problems

02/16/17



The initial problems are finally here! The cardboard rolls that I am using to make the air more centralized in my wind tunnel keeps falling off. I need to either go smaller so that it can structurally be more stable as they are too big or try to find better duct tape. This is so frustrating as even with these cardboard rolls inside the wind tunnel, the air still seems like its not as centralized as I want it to be. I am also thinking about using straws to see if that makes it better. Straws would also make it easier for me to duct tape them to the wind tunnel as I wouldn't have to worry about the symmetry of them in the wind tunnel. The cardboard rolls were pretty big so I had to actually plan out were to keep each one so that it would be symmetric, but with straws I can just put a bunch together because they are so small. I was also thinking about using toilet paper rolls as they are not too big or too small,but I feel like I should use it for the outer layers and for the inner layer use straws so the air would get pretty centralized as it goes through the straighter part of the wind tunnel. I knew these engineering problems were gonna arise, but now that they are here this whole process is starting to be more stressful than fun.

Introduction

02/14/17



Hello everyone, and welcome to my blog!


My name is Sayish Karthikeyan, and I am a senior at BASIS Phoenix High School. This blog is dedicated to cover the experiences of my internship at the Challenger Space Center. I am extremely happy to cover what I am doing at the Space Center and hope you guys will join me on my journey.


My project's purpose  is to build a wind tunnel that can help teach students who come to the Space Center about aircraft stability and wing structures of planes. It will help students understand the integrity of a plane and its structure. This model wind tunnel that I will construct will be used as a layout for a more permanent display at the Space Center. After I create the model design, we will start to work on the real display and wind tunnel to keep at the Space Center. This permanent display at the Space Center will really help the kids who come visit understand what a wind tunnel is and how it is used. They will understand the importance of a wind tunnel and how it is used to test the stability of any aerodynamic structure. There are many different ways to construct a wind tunnel so the research I will be doing is to understand the different types and the advantages and disadvantages of each one. The engineering side of the wind tunnel will be my main focus, as a way to understand the nuances that goes behind creating this structure.


What is a Wind Tunnel? A wind tunnel is a tool used in aerodynamic research to study the effects of air moving past solid objects. A wind tunnel consists of a tubular passage with the object under test mounted in the middle. Air is made to move past the object by a powerful fan system or other means.

Challenger Space Center

You can view my proposal here.

You can view my syllabus here which outlines what I will be doing on a week to week basis at my internship.

The cone

02/08/17



It is my third day at the internship and I finished the cone structure for my prototype. There are few errors with it as the fan is not a perfect box leaving the corners exposed. I am thinking about adding some material in the corners to make it enclosed allowing the wind from the fan to be more centralized.

The cone

Design of the Wind Tunnel

02/07/17



It is my second day at the internship and my first blog post. I have started to work on the design of the prototype wind tunnel which is what we will use as a layout to make the real one for display at the Challenger Space Center.

This picture shows the design of the prototype wind tunnel.