ANSYS-Fluent Rotating Fluid Experiments for Understanding abrupt climate change

10/25/10

Abstract:

This project is a global climate change project utilizing a rotational tank to check the sensitivity of our climate system to external perturbations. The focus is on rotation rate and differential temperature contrast. In order to better understand how sensitive the Earth’s climate is to external perturbations, we have begun to supplement the laboratory experiments with numerical simulations using ANSYS-Fluent, a Computational Fluid Dynamics (CFD) solver that can produce three-dimensional temperature and velocity under specified geometry and boundary conditions. Mimicking climate change, several flat-bottom runs have produced a wide range of behaviors of the fluid flows by changing the imposed temperature gradient and rotation rate. In addition, we have finished a design of a sloping bottom component to our rotational system and submitted it to ASU’s research machine shop for further analysis in our climate system. It will enrich the dynamics of the fluid system by including Rossby waves. An attempt is also underway to cross validate the laboratory experiments with numerical simulations using the computational fluid dynamical solver in ANSYS-Fluent. With this new system an entirely new set of experiments will be conducted with the rotating tank plus a sloping bottom to show the outcome the experiments that will be compared to the experiments without a sloping bottom as well as the numerical simulations using Fluent to help understand global climate change with a focus on information and technology to produce a meaningful change on the grand challenge aspect of sustainability.

10/2/2010

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 What we have simulated in the lab thus far:

     Here, we are preparing the tank for simulation of the global atmosphere.

Here is the begining stage of the zonal flow taking place in the rotating tank with no pertrusion.

 Reference from: http://en.wikipedia.org/wiki/Rossby_wave,

1. Picture Mesh of Tank in ANSYS-Fluent 12.1 with now an added object to perturbe the system.The Mesh size of the cylinder is 42,1392 cells.

The primary reasoning in adding this newly object is to create a distrurbance within the system to aid in the creation of wave patterns.

Figure 10.8. Multi-model mean of annual mean surface warming (surface air temperature change, °C) for the scenarios B1 (top), A1B (middle) and A2 (bottom), and three time periods, 2011 to 2030 (left), 2046 to 2065 (middle) and 2080 to 2099 (right). Stippling is omitted for clarity (see text). Anomalies are relative to the average of the period 1980 to 1999. Results for individual models can be seen in the Supplementary Material for this chapter.

IPCC Fourth Assessment Report - Working Group I

Chapter 10 Global Climate Projections

Source can be found here: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/suppl/chapter10/Ch10_indiv-maps.html

9/18/2010

• 1. Temperature Profile

• 1. Heat Flux Profile

• 1. Picture Mesh of Tank in ANSYS-Fluent 12.1

The geometry/Mesh of the rotating tank generated in ANSYS. The inner cylinder represents Earth’s polar region, and the outer warm cylinder represents Earth's equator region.