Week 2 Challenge : Surface meshing on a Pressure valve

Aim: check for the geometrical errors and perform Topology cleanup accordingly. Set three different target lengths as three different cases and mesh the model.

• Target length = 1mm, 3 mm and 5 mm
• Element type = Tria

Procedure:

• In the checks icon click on geometry and select options including single cons,double cons etc to check the errors and click on execute.
• Now errors on the surface are visible .
• now do topology cleanup using new option in faces and also use fill hole option in cons section.
• while using new in faces select the surface type accordingly and follow the instructions ,for eg:if existing surface is selected then select cons and then select a face.
• if the surface is not properly alligned in some cases select cons seperately by switching to ENT mode from PID region.
• after completing cleanup,again check for geometrical errors and make sure that no other errors are there other than the triple con which we actually doesnot consider as a error.
• for meshing properly,reduce the nearer lines and non significant lines on the surface using 'cut' option.
• now assign pid to the different parts of the body, in properties click on new>pshell>pshell and then give a name now a new pid is created.
• to assign pid to a particular part right click on the pid,click assign option,select the part and then middle click , likewise assign pid to all the region. A part inside a body which is not connected can be differentiated and selected seperately by switching to 'pid region' option from 'ent'.
• assign regions including:inlet,outlet,body,base surface,coloumn,valvehead and spring.
• the already existing shell property can be deleted by undeleting any surface,use topo to connect the surface with already existing surface and then delete the shell property.
• now switch to mesh mode
• mesh the model with target length=5mm and element type =tria
• first click on length assign values in perimeter and macros as 5 mm.
• then also assign length in mesh parameter and element type.
• in quality criteria set the minimum and maximum length =3 and 7 respectively.
• now use spot mesh and mesh each part of the model,to easily mesh select a particular part and click on show only and select visible on spot mesh.

Learning outcomes :

• for topology cleanup we can use check option where we can find geometrical errors by selecting options including single cons,double cons,triple cons,cracks etc.
• for filling the incomplete surfaces we can use new in faces and select a surface type and select cons and complete the surfaces.
• fill hole option in cons are also used in some cases to complete the surfaces.
• we can use ent while isolating a neighbour from a part and can use pid region when we need to isolate whole body near the part.
• small surfaces and significant lines can be deleted by cut option.
• we can create pid s to each part of the model in properties by creating new pshell and assigning it to the parts,then we can isolate by turning off the bulb and work on that part while meshing so that less complication.
• also we can lock screen using lock option.
• while meshing the model,we used 3 different target lengths =1,3,5 mm, each meshing was different and the best meshing was when the target length was set to 1mm.

Result:checked for the geometrical errors and performed Topology cleanup accordingly and set three different target lengths as three different cases and mesh the model.

Conclusion: we set 3 different target lengths =1,3,5 mm, each meshing was different and the best meshing was when the target length was set to 1mm.As some parts of the model is having smaller area and length than the set target length it tends to perform meshing not properly.

for eg: when we used target length=5mm the spring and some parts of valve head and in some other areas the meshing was not proper,when checked the surface length there is less than the target length.

then when the target length is set to 3mm and in some areas meshing was not good,but comparing with target length=5mm it was better.

then by switching the target length to 1mm the meshing was perfect throughout the surface.

while meshing selecting target length is very important,we should select the target length by analysing the surface length and area of the parts of the model which is to be meshed.