Week 2 Challenge : Surface meshing on a Pressure valve

AIM- Surface meshing on a Pressure valve

OBJECTIVE- Check for the geometrical errors and perform topology clean-up accordingly

Set three different given target lengths and mesh the model.

Target length = 1mm, 3mm and 5mm

Element type = Tria

PROCEDURE-

first, open the given geometry in the software through the file

Geometry checks- checks the geometrical error of given geometry using the cheks command there is definitely errors present. if select all errors, we can see those errors on the geometry as white lines. the error may be like, hole/single coon which is basically represented by red line/triple coons...

topo-logical clean up- in this, fill holes by using coons option or by fill hole option. but generally, we required a preview which is only shown in coons option, not in the fill hole. so choose option acc. to conditions. as u fill all holes u can't see any red coon and that is great.

in checks, it shows triple coons as errors, but sometimes it is needful so avoid such errors.

commands that can be use in TOPO

create PID's -

after completing topo next task is assign pid's

PID means the property ID. which is usually used to set the object in CFD Platforms. which will store some information about geometrical entities and then be used when you set up your model for CFD.

We can use PIDs by using the properties option at the top,

create separate pid's of each component as follows,,

• body
• inlet
• outlet
• base
• shaft
• valve head
• spring

In order to create a new PID, left-click on PID the a properties pop up will appear then right-click on properties, new- p shell- p shell.You can change the colour by double clicking on the colour box.

MESHING- after assigning PID's next task is meshing.

what is meshing?

-Dividing a surface or solid into little pieces on which mathematical equations are applied and then the results on each little piece are brought together to create the result for the whole object.

Here we have three different target lengths as three different cases and we have to mesh the model with all three different lengths.

Target lengths = 1mm, 3 mm and 5 mm

Define in mesh parameter as TRIA mesh it is a element type.

TARGET LENGTH = 1 MM

always while meshing we have to define the target length. to define target length, select perimeters under Mesh module.

assign the value as 1 mm in both perimeter and macros

then assign the target lenght in mesh parameter and also element type as TRIA

after this also assign max and mini length in quality criteria

now in MESH-GENRATION there is SPOT-MESH select it and then select the whole body it will gives u following result.

in a wire- frame mode

internal pid look likes as

TARGET LENGTH = 3 MM

now as we change the target length as 3 at different places i.e perimeter/macros/mesh parameter

by using spot generation it will give result as,

so basically as compared to target length=1 target length=3 so mesh length =1 part gives better geometry

TARGET-LENGTH = 5

For last case , as we applied target length = 5 change it in mesh parameter, perimeter and in macros

now use spot mesh will gives result as

valve head and spring looks unperfect bcause of its original size i.e length is minimum than given target length as 5 so basically we have to change its mesh length/ targrt length only this type of pid's/small objects.

so for this delete its mesh by using erase option from mesh-genration. then after this change its perimeter acc.to fit size i.e 1also do the same in macros. also assign the same target length in mesh parameter as 1. also change its max nad mini. lenght.

it will gives u a good result.

CONCLUSION-

as we can see from above fig. in a wire-frame mode outer part of the body .i.e the part whose actual length is more than the target length is mesh in a good way but whose actual size is less than the target length it not gives great result so for that we can mesh these type of part seprately. now clearly we can see in the above fig. internal part also gives great results.

so as smaller the target length/mesh size gives a better mesh quality.