A mesh is a barrier made of connected strands of metal, fiber, or other flexible or ductile materials. A mesh is similar to a web or a net in that it has many attached or woven strands.
Hi everyone, I would help in such problem. i have tried to use a fresh card, but it always gives an illegal data signal am using mcnp6. here is my fmesh code. thanks
FMESH44:n GEOM=X Y Z ORIGIN=-10 -10 -10
IMESH=-50 IINTS=5
JMESH=50 JINTS=11
KMESH=50 KINTS=8
EMESH= 1e-7...
Are the K-point mesh and monkhorst pack same. I was reading research papers using VASP and in some papers as the number of cells increases the Monkhorst Pack increases but in others the K-Point mesh decreases. Could some one clarify how these are used in the calculations.
Hi,
I've a question related to the graph theory.
Take a connected graph with ##n## nodes and ##b## edges. We know there are ##m = b - n + 1## fundamental circuits.
Which is the total number of nonempty circuits or edge-disjoint unions of circuits ? If we do not take in account the circuit...
I'm analyzing a longitudinal weld using the effective notch method to modell it. This means my mesh must be fine and more importantly very specific. To do this, I generated Keypoints where I want the nodes of the finite element mesh to be and this where I was stumped.
I want to mesh it using...
Hi, All!
Can anyone help me to construct a card for calculation of a spatial activation? Reaction is 27Al(n,p). I used a tmesh card for calculation of neutron flux as:
tmesh
rmesh21:n flux
cora21 190 9i 210
corb21 -10 9i 10
corc21 -10 9i 10
ergsh21 0 20
endmd
Somewhere in a problem I...
Hi everyone,
I am struggling to understand the difference between FMESH and MESH.
FMESH is used to create a mesh superimposed with the geometry but...what does MESH? Is it only involved in weight-window generation and not needed for mesh tallies?
Thanks in advance for the clarification.
Hi everyone,
I am using MCNP6.2 and trying to set up a cylindrical coordinate in a reactor channel. The origin as the midplane of the channel.
In my attempt of setting up a cylindrical FMESH with the origin on the z-axis at the bottom of the channel (so z<0) I got this fatal error message...
Hi there, I have managed to work out the kirchoff's law bit but for the other two bits I just cant get started as I can get my head around it, its due in on monday I dont know why I left it so late!
the simple rectangular isoparametric element (curved edges element) can be used to generate many complex shapes like..
square to circle
square to triangle
two square elements to annular.
and the results i calculated in python code (2D case) are very accurate, then i confused why to use complex...
I am building up a mesh via defining a background mesh (using blockMesh) and snappyHexMesh
I am dealing with the STL 2D Mesh surface (I cannot uploaded because PF doesn't accept zip files nor STL).
My issue comes when I want to open it. When I run vi constant/triSurface/river.stl in the linux...
Happy Holidays! I saw your posting on airflow thru mesh screen and went to Perry's looking for answers. I haven't found what I'm looking for yet and was wondering if you can help?
Our problem concerns bees coming down the chimney and how to stop them.
We installed a Lymance chimney damper with...
Hi all,
Sorry of this is a silly question but it is one that recently came to mind and I cannot seem to find an answer to it: "should I change my mesh depending on the type of FEA analysis I am doing?"
My feeling is that I should not change it, but that is a total guess on my part.
Any...
Hello,
I followed the following example for modeling the induced current from a moving magnet in a coil https://www.comsol.com/support/learning-center/article/Modeling-Induced-Currents-from-Moving-a-Magnet-Through-a-Coil-9871/112
If I have a bigger model with a bigger displacement of the...
For a project I am currently facing a problem that I find difficult to solve.
I am developing a shielding portal that uses a mesh to blocks UHF RFID signals. I would like to use aluminium mesh due to it being lightweight and its attenuation properties. The frequency of UHF RFID signals in the...
Hello,guys,
I wonder how to use mesh tally to calculate dose.I set a cylinder，and set the material of the cylinder.Then I want to divide a cylinder into smaller cylinders in a direction perpendicular to the z-axis.And I need to record the flux of each mesh,use dedf card to get dose.
I have tried...
I've tried to solve the following circuit using mesh equation, but the solution seems to differ from my attempted answer.
Mesh circuit as follows:
My mesh equation is:
-10+3(i1)+2s(i1-i2)=0 (for the mesh on the left)
and
-10+12(i2)+6s(i2)+2s(i2-i1)=0 (right mesh)
However the answer seems to...
Hi PF!
I'm running a two-phase simulation, which takes a long time to run. The simulation is simply a partially filled tank being drained in zero gravity, and the tank is a little smaller than a mailbox (~ 160 X 40 X 40 mm). Before running the simulation I would like to know if my mesh is...
Hallo everybody,
I am using a mesh-based-weight window generator. It is clear to me that the coarse mesh must cover the full geometry; my doubt is about the fine mesh. Is it possible to define the fine mesh only in a part of a geometry, for example telling to MCNP to make 5 bins between y1 and...
Here's my work.
I have the correct answer, but I'd like to know why this only works for (i1-i2) plugged in for i_delta as opposed to what I initially put: i_delta = i2-i1. You can see this in the blue text above versus what I originally had in red.
(New thread following up to a conversation in another thread).
I'm using SimFlow 3.1 with OpenFOAM 5 on Linux to try to evaluate the drag coefficient of a water rocket body, constructed from a 2-liter Coke bottle with a conical nose, traveling through air at 77 m/s.
This should be a simple...
The answer says its 1 meter i don't understand how they arrived at this, The mark scheme suggests that the 50mm is the resolving power or Rayleigh criteria?
https://downloads.umutech.net/Physics/Past_Papers/PA05/Astro/MS/physics_u5_astro_ms_jan_2003.pdf
I hope someone here can explain this curious light effect!
Some background: I have a table with a laptop on it, and a chair sitting at this table that has a mesh back on it that has a pattern of ~2mm holes cut into black material in a regular pattern. I happened to notice one day that I could...
Homework Statement
Find the current in each resistor. (refer to uploaded diagram)
Homework Equations
##Kirchhoff's Law: I_s=I_1 + I_2##
Mesh analysis method
The Attempt at a Solution
I'm calling ##I_s## the total current before and after the current splitting up, and ##I_1## and ##I_2## are...
Homework Statement
Homework Equations
I've worked out the KVL's for four meshes, I1, I2,I3, and I4. Would anyone be able to error check this for me?
Also, would I be correct in thinking that I can use ohm's law by dividing V1/Z1 to find the current of the first mesh and likewise with...
I have four arrays of data xvalues[], yvalues[], zvalues[] and wvalues[] and I want to create, from this data, an interpolated function w = f(x,y,z). Is it easy to do this in python using first a meshgrid and then calling scipy's interpolation?
e.g toy set up is something like, where wvalues...
I really don’t understand the advantage of 3 phase flow, phase field module in comsol. For example, if I want to simulate a compound droplet inside a fluid. Can’t I use the moving mesh with 2 fluid-fluid interface? If yes. When should I use the 3-phase flow, phase field simulation?
Homework Statement
Hi mates, I have problems solving the third part of this exercise, I've already done all the previous calculations.
Given the following circuit, where the switch S is open, the power supply = 50 volts and:
The initial charge in the C capacitor: QC = 0 coulombs
The initial...
Hi. I am practising for my test and since I don't have the correct answers, I don't know if what I'm doing is right.
I tried to solve this problem, can you check it and correct if it's wrong?
Here's a clearer picture of the circuit.
I suspect Uab isn't right, but am not sure. Thanks...
Homework Statement
Hi guys I'm doing the mesh analysis of AC circuit and looking for some guidance.
Here is the mesh picture and some components data:
Homework Equations
Kirchoff's voltage law and current law.The Attempt at a Solution
I decided that mesh currents are going in clockwise...
Homework Statement
[/B]
Determine, Using the values given in TABLE A, the current I in the circuit of figure 2 by
(a) Mesh analysis
(b) Nodal analysis
Circuit diagram and given variable attached.
V1 = 120
V2 = j120
V3 = 14.142+j14.142
Z1= 2
Z2=-J5
Z3=4
Z4=-J5
Z5=J4Homework Equations
[/B]
KVL...
When using the Mesh Current Method and you encounter a loop with a current source that is going opposite to the mesh current do you write it down as a negative current source?
Homework Statement
The problem asks to solve for i1, i2, and i3 using the mesh method in the following circuit:
I will also include the link, because I noticed I am having trouble attaching the image to the post: https://imgur.com/a/bBvuLXM
I would also like to confirm the answer by solving...
I want to start a project that requires parallel code for adaptive mesh refinement. I don't want to re-invent the wheel, and was hoping to leverage an open source library as a starting point. Does anyone have experience with any of these codes and could make a recommendation? At this point I...
I figured this would be the best place to ask as there doesn't seem to be a FEM/Simulation specific sub-forum here, but I am looking for some help regarding mesh generation in ANSYS Maxwell. I have an array of "micro-needles" that I am applying a voltage to in order to determine the electric...
I've recently moved into a house with ADSL2+. It is a very old old method of connecting to the internet. I'm having issues with the internet speeds as well as just generally connecting my devices.
The biggest issue is that there is absolute no ethernet in the entire house. There is only one...
Homework Statement
I have a circuit that I am to analyse and find I. I am told to use an excel matrix sheet given to me to solve 3 unknowns. I have 4 loops so this is a problem. I have made an attempt using three loops and referred to a previous thread on here for some help. It says I can do...
Dear all,
we are using MCNPX for the simulation of proton beam interactions at our proton therapy facility. But now we found a very strange behavior within a RMESH1:h flux tally:
In an even very simple geometry we see a constriction or rather offset of the Proton flux at surfaces (surface 1118...
Given the circuit in the diagram I was wondering would I be able to make ib equal to the mesh i3.
I have the equation for my Super Mesh at i1 and i3 which is:
-25+30i3+5Va+20(i3-i2)+10(i1-i2)=0 (1).
The mesh i2 is equal to -2A (2).
subbing (2) into (1) gives:
-25+50i3+5Va-30i2+10i1=0 (3)...
< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >
Hi,
I couldn't figure out from the equation that relate the current source IS to IA and IB. If both IA and IB is coming from the same direction and the positive terminal has been predicted...
I would like to know the sheet resistance of a metal mesh that consists of 3 larger busbars (W=0.0025 cm L=0.3 cm) and 10 smaller fingers (W= 0.0002 cm L= 0,16416 cm) which are all connected by a big collection bar. The thickness of the whole layer is 0.00. This collection bar has been...
Homework Statement
Write the equations for the two mesh current i1 and i2. The circuit and the answer to mesh 1 are showing below
Homework EquationsThe Attempt at a Solution
My answer came out to be the same as the answer key except for the -25di1/dt term. It seems that this term gets...
Homework Statement
Homework EquationsThe Attempt at a Solution
So far I was able to transform each element into the frequency domain:
I am just unsure how to work with the dots to find the mesh currents. Can someone explain? Thanks.
Hi,
I'm developing a data structure to represent 3-D meshes for numeric simulation. I want those meshes to be able to handle any type of polyhedron (not only the classic tetra and hexahedron). The best data structure that I could find was one based on half-edges (or darts), such as this one...
Homework Statement
I need to use mesh analysis to find the three currents:
Homework EquationsThe Attempt at a Solution
The answers are I1= -1.25A, I2=0.125A and I3 = 1.125A
I don't know where I messed up for I3
Homework Statement
Vs = 100cos(2000t)
Homework Equations
KVL, KCL
The Attempt at a Solution
My mesh equations are:
-Vs + I1(30-12.5j)-I2(120j)=0
4Ix+I2(120j+20)-I1(120j)=0
Ix = (I1-I2)
Are these correct? When I solve I get a different result than when I do nodal analysis.
Homework Statement
Find the:
-Complex power delivered by source
-Power factor of total load
-Is the power factor leading, lagging, or in unity?[/B]
Homework Equations
KVL/KCL
The Attempt at a Solution
I want to solve this via mesh analysis to get currents.
Mesh1: -10V + V1 + 0.75V1 = 0
V1 =...
Homework Statement
Find power absorbed by resistor, capacitor and inductor. Find the total complex power absorbed by all the loads.[/B]
Homework Equations
KVL/KCL
The Attempt at a Solution
I want to solve this using Mesh analysis. There is a supermesh where the 5A source is, so I start it...