<h3>About Tracer Experiment</h3>
<p>This experiment is conducted by injecting a fluid with nonreactive species of certain concentration inside a column or core composed of sand. The injection of fluid can either be in the form of a pulse or it can be continuous injection. This type of experiment can be useful to characterize the static and dynamic properties of a subsurface and can help us gain a better understanding of the geology and flow dynamics of the fluid.</p>
<h3>Known Information</h3>
<p>In this type of experiment we typically know the velocity of the tracer through the column, say <span class="math-container">$v$</span>, the length of the column <span class="math-container">$L$</span>, the injected concentration of the tracer <span class="math-container">$C_0$</span>, a time series of the fluid concentration at the column outlet <span class="math-container">$C$</span> <span class="math-container">$\text{vs.}$</span> <span class="math-container">$t$</span>, which acts as an output data from this experiment.</p>
<h3>Questions</h3>
<ol>
<li>Which equations are typically used to characterize the flow of
nonreactive tracer in a porous media at laboratory scale?</li>
<li>How can we use the known information to estimate the fluid dispersion coefficient (a measure of fluid velocity variance)?</li>
</ol>

CC BY-SA 3.0
2015-11-25T11:42:33.420Z
Welcome to the Earth Science stack exchange! I see that your question is a copy-paste of a homework problem, apparently from a civil engineering course at the University of Windsor, Canada. Please read [the site policy](http://meta.earthscience.stackexchange.com/questions/316/how-do-i-ask-homework-questions-on-earth-science-stack-exchange/317#317) on posting homework questions here. As it currently stands, your question isn't a good fit for this site.
Pont
CC BY-SA 3.0
2015-11-25T21:56:16.980Z
I believe this is within the scope of earth science as it directly relates to hydrogeology, contaminant transport modelling, and experimental determination of parameters describing natural processes in the hydrosphere. However, the question needs to be reformulated to meet the homework guidelines.
haresfur
CC BY-SA 3.0
2015-11-26T08:20:30.433Z
@haresfur I agree that the subject matter itself is on topic. If the question were edited to fit the homework policy, I'd vote to reopen.
Pont
CC BY-SA 3.0
2015-11-27T16:19:31.307Z
@Pupil I took the homework policy to be part of the "scope defined in the help center", but on inspection it doesn't actually seem to be linked there. I think that "off-topic" is still the best close reason (because all the other options -- dupe, unclear, too broad, opinion-based -- are clearly inapplicable) but it should probably have been "Off-topic -> other" with a custom message rather than "Off-topic -> not earth science". I'll bear this in mind next time, but I don't know of any way to change a close reason after the question is closed. If you know of one, please advise :).
Pont
CC BY-SA 3.0
2015-11-29T21:45:46.977Z
I'm reopening this question, as with the latest edit, it makes the actual questions much clearer.
hichris123
<hydrology><fluid-dynamics><hydrogeology>
How to characterize flow of nonreactive tracer in a porous media?
user4883
# How to characterize flow of nonreactive tracer in a porous media?

(Asked by: username_0 on 2015-11-25)

### About Tracer Experiment

This experiment is conducted by injecting a fluid with nonreactive species of certain concentration inside a column or core composed of sand. The injection of fluid can either be in the form of a pulse or it can be continuous injection. This type of experiment can be useful to characterize the static and dynamic properties of a subsurface and can help us gain a better understanding of the geology and flow dynamics of the fluid.

### Known Information

In this type of experiment we typically know the velocity of the tracer through the column, say $v$, the length of the column $L$, the injected concentration of the tracer $C\_0$, a time series of the fluid concentration at the column outlet $C$ $\text{vs.}$ $t$, which acts as an output data from this experiment.

### Questions

1. Which equations are typically used to characterize the flow of
   nonreactive tracer in a porous media at laboratory scale?
2. How can we use the known information to estimate the fluid dispersion coefficient (a measure of fluid velocity variance)?

**Tags:** hydrology, fluid-dynamics, hydrogeology

> **Comments:**
> **username_1**: Welcome to the Earth Science stack exchange! I see that your question is a copy-paste of a homework problem, apparently from a civil engineering course at the University of Windsor, Canada. Please read [the site policy](http://meta.earthscience.stackexchange.com/questions/316/how-do-i-ask-homework-questions-on-earth-science-stack-exchange/317#317) on posting homework questions here. As it currently stands, your question isn't a good fit for this site.  
> **username_2**: I believe this is within the scope of earth science as it directly relates to hydrogeology, contaminant transport modelling, and experimental determination of parameters describing natural processes in the hydrosphere. However, the question needs to be reformulated to meet the homework guidelines.  
> **username_1**: @username_2 I agree that the subject matter itself is on topic. If the question were edited to fit the homework policy, I'd vote to reopen.  
> **username_1**: @Pupil I took the homework policy to be part of the "scope defined in the help center", but on inspection it doesn't actually seem to be linked there. I think that "off-topic" is still the best close reason (because all the other options -- dupe, unclear, too broad, opinion-based -- are clearly inapplicable) but it should probably have been "Off-topic -> other" with a custom message rather than "Off-topic -> not earth science". I'll bear this in mind next time, but I don't know of any way to change a close reason after the question is closed. If you know of one, please advise :).  
> **username_3**: I'm reopening this question, as with the latest edit, it makes the actual questions much clearer.  

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## 0 answers

