Thesis

Milestones of Thesis
Abstract 1st Semester
Purba, L. P., Tekasakul, P., Maliwan, K., 2007
ADFIEN MODELS: Efforts to Find the Better Models for RSS cooperative Smoke Aerosol Flow Simulation. (Abstract Pra-Thesis Master of Engineering in Mechanical Engineering)

Abstract Progress Report of Thesis by the end of the 1st semester

Abstract 2nd Semester
Abstract Progress Report of Thesis by the end of the 2nd semester

Abstract 3rd Semester
Abstract Progress Report of Thesis by the end of the 3nd semester

PEC-6(PSU Engineering Conference - 6 )

MENETT22, Mechanical Engeneering Networks 22th Thammasat University Thailand

DPM-Study

all about injection initialization?
visit: http://www.cfd-online.com/Forum/fluent_archive.cgi?read=49321

how to calculate concentration of DPM?
visit: http://www.cfd-online.com/Forum/fluent_archive_2006.cgi/read/35234

search about DPM discussion:
http://www.cfd-online.com/Search/cgi-bin/htsearch?config=htdig&exclude=&words=concentration+DPM&restrict=cfd-online.com%2FForum%2Ffluent&method=or&sort=score

air-water-are-examples-of-newtonian-fluids

Fluid Mechanics defines a fluid as:
A substance which undergoes continuous deformation when subjected to a shear stress.
A fluid substance; a body whose particles move easily among themselves.
Fluid is a generic term, including liquids and gases as species.

Water, air, and steam are fluids-->Newtonian Fluid

The resistance to deformation offered by a fluid under a shear stress is called fluid viscosity. This is an important parameter to categorize the various types of fluids, or fluid models (for Fluid Mechanics calculations). The simplest fluid model is the perfect or ideal fluid. This model corresponds to a hypothetical gas or liquid that offers no resistance to shear, and thus has zero viscosity (an inviscid fluid). This model is sometimes used for real fluids with low viscosity.

Ideal Fluid (Perfect or inviscid fluid) - Hypothetical gas or liquid with zero viscosity
Newtonian Fluid - Fluid with a constant viscosity at a fixed temperature and pressure
Non-Newtonian Fluid - Viscosity is a function of shear stress

simulation-proposal-experiment

...SIMULATION GAMBIT & FLUENT...
airflow: from 8in, 1out [i have been done] --> 8in, 6out [prepare Geometry in Full scale]
particleflow: from 8in, 1out [about today, just start, by better view] --> 8in, 6out [prepare Geometry in Full scale]

...WRITING PROPOSAL [REVISED Ed.1]...
Have to write my report up to today...

...EXPERIMENTAL MEASUREMENT PREPARATION...
V, T: ready to measure
C: need to prepare

...2007.25.08...

3ddp-solver

use 3DDP solver....

parameter u.r of momentum and pressure by default...

results:
after iteration 9 AMG Solver still serro...

according to the cfdfluent.com (discussion) says that need to use u.r one by one .... still don't have pattern or formula how to set the discretization methods....

parameter u.r of momentum and pressure by momentum=0.39 and pressure=0.31...
after iteration 4139 error AMG solver...

parameter u.r of momentum and pressure by momentum=0.39 and pressure=0.61...
after iteration 1 error AMG solver...

parameter u.r of momentum and pressure by momentum=0.61 and pressure=0.39...
after iteration 937 error AMG solver...

so try about BC's of the Simulation.....

equisize-skew->-0.97

Meshing success? but EquiSIZE SKEW >0.97 (11 or 16 cells)?

May have to re-fine meshing of the geometry...by:
*. coarse mesh then if need more fine mesh have to try methods below...

Because Meshing in GAMBIT automatically generated mesh (especially in 3-D) in most cases, can not provide uniformly high quality in un-structured mesh (hexahedral or tetrahedral) for complex geometry.

On the surface, the unstructured mesh does have advantages to cover large areas of complex geometry, but, in reality, a high quality mesh is always hard to obtain.

One says that need to go back to the blocking of the geometry (meshing process): to divide the geometry into smaller pieces and re-create the surface geometry so that can avoid the highly skewed cells.

**. have to try long iteration until 10^-6 criterion meet.... (already done, but still not convergence)....

have to try one by one....

And .... just an information from CFD source: it must take more time in Meshing Process and Convergence Process......

Under-relaxation-momentum

About:....

Error: AMG Solver ...temperature

Solution:
* by Modification of Under-relaxation of Momentum become less than default (0.7) have to try become 0.6....or: 0.5, 0.4, 0.3, 0.35, 0.39....
for 0.5: 500iteration success but after iteration 701 error AMG Solver again...
for 0.4: error after iteration 1185...
for 0.3: error afater iteration 359...
for 0.35: error after iteration 763...
for 0.39: error after iteration 1750...
for 0.396 or 0.389: have to simulate beside check about Meshing or Coupled Solver and not Segregated...

for 0.396: error after iteration 197...
for 0.389: error after iteration 857...
for 0.37: error after iteration 456...
So, want to check it up of coupled...

conclution for u.r. of momentum is about=0.39 and for pressure is about=0.3

but ok before fixed it...need to set the under-relaxation of Pressure....the default is 0.3 but i have to try the 0.28, 0.29 and 0.32 to know influence of this value...

for this use the same convergence criteria that is 1.0e-06 for all graphics...
for 0.28: error after iteration 1086...
for 0.29: error after iteration 264...
for 0.3: error after iteration 1750...already done
for 0.31: error after iteration 2229...
for 0.32: error after iteration 838...

So, the best configuration based-on under-relaxation of pressure and momentum is 0.31 and 0.39 for this case eventhough it's still has error in AMG solver: temperature.

Now, before try coupled solver....need to try to change the the BC's becouse one says that AMG solver and Reversed flow come from settings in BC's....