Vapor Vortex: Stage fog on a table is pulled up into vortex cores formed when a hand flicks upward from the table

Vapor Vortex: Stage fog on a table is pulled up into vortex cores formed when a hand flicks upward from the table

 

By Jason Savath, For Get Wet 2016

Vapor Vortex

The Physics and Art of Fluid Flow

Introduction

This project, “Get Wet,” is designed to help students get accustomed to using a camera and capturing the art and physics of fluid flow. The fluid flow captured in this project is vapor vortices. Two separate vortices as columns of smoke can be seen rising up on the surface of a table. This image was captured with the assistance of Jeremiah Chen and David Leng using a Nikon camera.

The Physics

sketch

The substance used in this project is vegetable glycerin vapor. The vegetable glycerin liquid is heated to the gas phase using Ni-80, Nickel and Chromium alloy, wire coils. The gas is then poured and distributed evenly onto the surface of a table with a room temperature of approximately 20 degrees Celsius. Using an upright flat hand, the wrist is flicked upwards to create the flow seen in the image. The hand motion caused instability in the air which created turbulent flow as shown in equation (1). As the hand rises, the velocity of the hand will increase resulting in varying wind velocities on the table. The varying wind speed is known as wind shear, the change in wind speed and direction across a small distance (Federal Aviation Administration). The diameters of the vortices are estimated to be between 1 and 2 inches with a height of 6 to 12 inches.

As the air blows around, it creates low pressure and a tube of air that rotates parallel to the surface of the table known as a vortex tube. As the vortex spirals, an updraft is created sending the vegetable glycerin gas upwards. This is the same concept of how twisters and tornadoes work (Marshall). The low pressure inside the vortex slowly increases as the radius from the center increases. This pressure gradient allows the fluid to follow the rotation path as well as preserving the form of the vortex. As seen in the image, the center of the vortex is denser than the outer portion; this is a characteristic of an irrotational vortex. An irrotational vortex is when the angular speed of the fluid in a vortex is inversely proportional to the distance of the radius. This is also an example of free flow because the hand is removed before the vortex was created (Siddique). Therefore, the flow is free and irrotational such that it does not have torque and that the tangential velocity stays constant as shown in equation (2).

Reynolds Number For Turbulence

 

eqn1

 

 

(1)

Velocity Equation Derived From Torque

 

eqnlist

 

 

 

Since change in moment is zero for free irrotational flow,

   eqn2

(2)

The Art

The medium of the artwork is a white smoke-like vapor produced by the vegetable glycerin. The background is a black table with a black backdrop. The white color from the vapor and the black background brings out the contrast of the image. The spirals inside the vortices are accentuated as the physics can be seen visually. The pool of vapor at the bottom of the image helps visualize where the vapor came from and how the updraft lifted it up into the air. The difference height and diameter of the vortices creates a unique feel to the image.

For this image, four light sources are being used. The sunlight seeps into the room from the cracks in the window to provide a natural ambient lighting. Two directional lights are placed behind the camera and shining on the vortices which provide the most lighting for the image. The fourth light comes from the back right allowing the vortices to be lit from the rear as well.

The camera was taken on the edge of the table to eliminate the edge as a distraction. The field of view was set to high because it is difficult to place a vortex directly in front of the camera and that the image needed to be taken in portrait to capture everything. An ISO of 25600, aperture F3.5, and shutter speed of 200 was used to ensure that the vortices will be focused and the image will be clear in the current lightings. Photoshop was used to bring out the contrast of the image and to crop the image appropriately.

Conclusion

The final image definitely has revealed both the physics and the art. However, some improvements can be made. The contrast of the picture can be increased in order to remove the background and highlight the vortices. The ISO of the image is a bit too high and it could be lowered to help with the image quality.

Setting up the environment to create art such as lighting and background was tedious as I haven’t had experience with aesthetic appearances prior to this project. Producing the perfect image by creating the vortices and taking a good picture took many hours. Overall, this was a learning experience that allowed me to “get my feet wet.” Upon completion of this project, I have learned the physics behind how vortices work. I have also learned how to use set up and take artistic images.

References

Brain, Marshall. Lamb, Robert (2000). “How Tornadoes Work.”

http://science.howstuffworks.com/nature/climate-weather/storms/tornado.htm

Federal Aviation Administration (2008). “Wind Shear.”

https://www.faasafety.gov/files/gslac/library/documents/2011/Aug/56407/FAA%20P-8740-40%20WindShear%5Bhi-res%5D%20branded.pdf.

Previous Post
Clouds First | 10/06/2016 | Peter Brunsgaard
Next Post
Buoyant plume from a cigar accelerates upward to transition from laminar to turbulent flow.

30 Comments. Leave new

  • Marco Gardi
    Sep 28, 2016 11:22

    Just like in the smoke ring image I think the lower end contrast intentionally conveys a less dramatic feel, breaking away from your usual smoke against a dark background images. For the purpose of viewing the flow I think the usual high contrast effect is more useful but from an artistic standpoint this is much more pleasing.

    Reply
  • Peter Brunsgaard
    Sep 28, 2016 09:34

    I’m amazed with the effect you managed to get with simply moving your hand on the table. It looks very omniscient. The choice to leave the photo as simply black and white definitely adds to the eerie feel.

    Reply
  • Joseph Hall
    Sep 27, 2016 23:49

    You did a great job in capturing the multiple vortexes in the image. The underlying smoke gives off a very ominous feel. Perhaps change the contrast around a bit to make the whites whiter and remove the background inconsistencies.

    Reply
  • Michael Lloyd
    Sep 21, 2016 12:16

    Nice crisp capture of the smoke, but the background is distracting. Setting the black value would help.

    Reply
  • Sierra Castillo
    Sep 20, 2016 19:34

    I love the way the image feels as though it is scaled much bigger than a small vape cloud. The focus is great. Perhaps a darker contrast between the smoke and the background would enhance this image.

    Reply
  • Marcus Gurule
    Sep 18, 2016 10:55

    Very interesting photo, I like how you were able to catch the vortexes perfectly. The focus of the photo was great I just wish that there was more contrast between the smoke and the background. Overall really great photo!

    Reply
  • Daniel Bateman
    Sep 16, 2016 11:00

    Very visually appealing flow! Good contrast. The two vorticies provide a point of curiosity for the view. The background seems very in focus and seems slightly distracting.

    Reply
  • Sean Harrison
    Sep 15, 2016 20:49

    Excellent contrast between the smoke and backdrop. Nice use of light from the front to have the tornadoes really stand out. In the future might want to try darkening background even further to help the tornados pop even more.

    Reply
  • Preston Marcoux
    Sep 15, 2016 14:32

    I like the multiple vortexes captured, it makes for a very striking image. I am not to sure if changing the ISO would help but maybe try and enhance the quality so that it doesn’t look as grainy.

    Reply
  • Harrison Lien
    Sep 15, 2016 10:33

    This image captures the art I like to see in images of vapors/smokes. Nice dark background, nice lighting and minimal shadows. The flow is intriguing, and definitely could be studied in an analytical method in this image. Nice photographic technique, I’d perhaps increase the contrast just a little bit, but it’s pretty darn good.

    Reply
  • Joseph Straccia
    Sep 14, 2016 19:35

    This is a very creative photo. The vorticies appear to dance out of a fog covered lake. I suspect that the two prominent vortex cores are a counter rotating pair formed from the sides of your hand. Some additional work to either post process the image and remove the background or just being mindful about direction of lighting may further enhance the appeal of this piece.

    Reply
  • Katherine Yarnell
    Sep 14, 2016 16:30

    Very cool image. The multiple vortexes and the tornado effect make this image very nice. It has very good focus. The edges are slightly distracting but it’s still a very good picture.

    Reply
  • Alexander Thompson
    Sep 14, 2016 15:42

    Great idea making a vortex with e-cigarette smoke! Even better, you were able to capture two large ones. Other than the background being a little distracting, which could be fixed with some contrast editing, this image is focused perfectly. The edges of the smoke are very crisp.

    Reply
  • David Leng
    Sep 14, 2016 12:41

    The multiple vortexes are very aesthetic to me. It resembles the fire tornado we watched in class and clearly illustrates the phenomena that is occurring. More contrast is needed, but focus is great.

    Reply
  • Schuyler Vandersluis
    Sep 14, 2016 12:38

    I love the color contrast, it makes the image really aesthetically pleasing. The only distracting element is the background, which could use a little more darkening.

    Reply
  • Katie Gresh
    Sep 14, 2016 12:38

    1. The image is dramatic and pleasing. The two vortices are visually pleasing. The composition of the vortices on a linear horizontal line lends to desiring additional vortices.
    2. The flow phenomena is clearly illustrated.
    3. The photographic technique with the highlights and shadows is excellent.

    Reply
  • Michael Waterhouse
    Sep 14, 2016 12:36

    Art: No distracting elements. Flow: Clearly illustrates flow. Can easily be understood. Photographic technique: Try to make the upper left hand corner of the background darker. It is a little bit distracting.

    Reply
  • Ryan Walker
    Sep 14, 2016 12:34

    A. Great contrast between smoke and background
    B. This image helps show the physics of the vortex
    C. Great focus on the smoke in this image

    Reply
  • Maxfield Scrimgeour
    Sep 14, 2016 12:34

    I am impressed on how this image was created. Were you able to lift your hand and shoot the camera at the same time or did you have help from another hand mixing the smoke? The contrast of this image is very nice and the focus on the smoke shows the intricacies of the tornado. I think the background in the corner is a little distracting and could benefit from a sharper backdrop to really draw all the viewers focus to the smoke.

    Reply
  • Mark Noel
    Sep 14, 2016 12:33

    1. Beautiful vortexes
    2. The background is a bit distracting
    3. More contrast could help

    Reply
  • Zachary Cymanski
    Sep 14, 2016 12:33

    Very intriguing image. fantastic visual of fluid flow with the multiple types of vortexes. Contrast was effective and focus seems to be spot on. Maybe play around with contrast even more

    Reply
  • Theo Petrides
    Sep 14, 2016 12:32

    – Intent was realized.
    – Can see the texture between smooth and turbulent areas.
    – The detail is visible and can be reproduced for other cool lighting applications.
    – Was not aware you could just knife your hand and lift it, would have assumed you had to do a twirly (technical term) motion.

    Reply
  • Daniel Luber
    Sep 14, 2016 12:32

    A full contrast range maybe be needed for this image. I feel like the composition is better based on having two vortexes. I also appreciate how the way you created the flow as fairly simple yet productive.

    Reply
  • Brett Sibel
    Sep 14, 2016 12:31

    Art: The white in the upper hand left corner could have been removed
    Flow: I love the two vortexes. Im very impressed you were able to do this with only your hand.
    Photographic Technique: The contrast here was the best of the smoke could

    Reply
  • Ryan Daniel
    Sep 14, 2016 12:31

    Art: detail in vortexes are very neat to look at.
    Flow: creative technique to create vortex.
    Photo: nice contrast from white smoke and black background

    Reply
  • Hunter Miller
    Sep 14, 2016 12:31

    I like this photo a lot. focus is good. Contrast is good. Framing is good. It is interesting. I have seen this effect before but never so clear. The vortex is so clear. If this is with the same settings as the other E-Cig projects it is very well done.

    Reply
  • James Julian
    Sep 14, 2016 12:31

    Art: The color contrast between the smoke and the background is very dramatic, but it could be a little sharper. The lines of the vortex are visually interesting.
    Flow: The flow is understandable and easily recognized. I don’t know if the flow can be precisely reproduced.
    Photographic technique: The background is slightly distracting, but the vertices themselves are well separated from the background.

    Reply
  • Branden Goldenberg
    Sep 14, 2016 12:31

    Aestheticly pleasing to say the least. The physics revealed are very interesting. Getting rid of the white in the upper left of the image may increase the overall contrast of the photo.

    Reply
  • Alexander Rosenberry
    Sep 14, 2016 12:30

    Very striking image. Great contrast, showing pure blacks as well as whites. Reminiscent of a small scale tornado, this photo captures a very interesting effect. Grainy quality from a very high ISO, but still looks great.

    Reply
  • Jeremy Parsons
    Sep 14, 2016 12:30

    I especially like how the image captures to different vortexes, one less mature than the other (I assume). Removing the background colors and texture may enhance the contrast and enhance the visual of the effect you have created.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Fill out this field
Fill out this field
Please enter a valid email address.

Menu