Real-time ASCEND/Solver - Revision history

Jpye at 13:18, 2 August 2010

2010-08-02T13:18:33Z

← Older revision		Revision as of 13:18, 2 August 2010
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	Contributed by: [[Dipak Chirmade]]		Contributed by: [[Dipak Chirmade]]


	== Real-time solver ==		== Real-time solver ==
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	If we calculate dCoffee/dt we can get a graph as shown in following diagram		If we calculate dCoffee/dt we can get a graph as shown in following diagram


	<div class="thumb tnone"><div class="thumbinner" style="width:602px;">[[Image:DTCoffee.png]] <div class="thumbcaption"><div class="magnify">[[File:DTCoffee.png\|<img src="/skins/common/images/magnify-clip.png" width="15" height="11" alt="" />]]</div>Rate of change of coffee temperature with reference to environment temperature.</div></div></div>		<div class="thumb tnone"><div class="thumbinner" style="width:602px;">[[Image:DTCoffee.png]] <div class="thumbcaption"><div class="magnify">[[File:DTCoffee.png\|<img src="/skins/common/images/magnify-clip.png" width="15" height="11" alt="" />]]</div>Rate of change of coffee temperature with reference to environment temperature.</div></div></div>

Jpye at 00:50, 1 August 2010

2010-08-01T00:50:58Z

← Older revision		Revision as of 00:50, 1 August 2010
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	As you can see, prediction after 1st step starts differing than actual measured reading meaning we needed to tune the step to get accurate simulated results.		As you can see, prediction after 1st step starts differing than actual measured reading meaning we needed to tune the step to get accurate simulated results.

			[[Category:Development]]

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2010-05-13T14:03:24Z

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←back to [[Real-time ASCEND]].

Contributed by: [[Dipak Chirmade]]

== Real-time solver ==

=== Runge Kutta based single step solver ===

''''' Work in progress! '''''

Real-time solver using Runge Kutta method is currently implemented as an extern method for initial testing purpose.
Building a stand alone real-time solver is already in progress.

Using real-time data reader, one can calculate dCoffee/dt for cooling of coffee example. From initial test, I have collected following logs
Source:[http://ascendcode.cheme.cmu.edu/viewvc.cgi/code/branches/dipak/models/dipak/Workspace_Broken/sensorreadings.logs <font color="orange">dipak</font>:models/dipak/Workspace_Broken/sensorreadings.logs]

If we calculate dCoffee/dt we can get a graph as shown in following diagram

<div class="thumb tnone"><div class="thumbinner" style="width:602px;">[[Image:DTCoffee.png]] <div class="thumbcaption"><div class="magnify">[[File:DTCoffee.png|<img src="/skins/common/images/magnify-clip.png" width="15" height="11" alt="" />]]</div>Rate of change of coffee temperature with reference to environment temperature.</div></div></div>

Todo: Application: Once we have dCoffee/dt, we can solve '''model''' like following

<source lang="a4c">Qdot = h A (T_coffee - T_amb)

Qdot = - m_coffee * cp_coffee * dT_coffee / dt

where Qdot is the heat transfer rate
h is the convection coefficient
A is the heat transfer surface area
T_coffee and T_amb are the coffee (+ cup) and ambient air temperatures, respectively.

m_coffee is the mass of the coffee + cup
cp_coffee is the average specific heat capacity of the cup + coffee etc</source>
<br />
Following graph shows simulated results from real-time solver Vs real-reading over 10 mins of time slot.

Source can be found at: Source:[http://ascendcode.cheme.cmu.edu/viewvc.cgi/code/branches/dipak/models/dipak/RealtimeSolver <font color="orange">dipak</font>:models/dipak/RealtimeSolver]
<div class="thumb tnone"><div class="thumbinner" style="width:602px;">[[Image:RK_Solver.png]] <div class="thumbcaption"><div class="magnify">[[File:RK_Solver.png|<img src="/skins/common/images/magnify-clip.png" width="15" height="11" alt="" />]]</div>Simulated results after 1*10 steps vs real reading</div></div></div>

As you can see, prediction after 1st step starts differing than actual measured reading meaning we needed to tune the step to get accurate simulated results.