Hi, Using dolfin-2019.1. Here is the relevant code excerpt: import dolfin as dlf DT = dlf.Constant(1e-4) # time step MU1 = dlf.Constant(1.0e-3) # dummy dynamic viscosity value RHO1 = dlf.Constant(917) # density G = dlf.Constant((0, -9.81)) # 2D rectangular channel mesh ---------- mesh = dlf.Re…

Here’s a mwe up to the point where the error occurs. I tested it and it runs identically to the full code with the same error. #!/usr/bin/python3 """ Two-phase flow transport model based on Gosman model with P1DG-P2 element (Cotter et al. Journal of Computational Physics 228, 2009), and the…

This term doesn’t make sense: abs(dlf.dot(u1_tld, n)) I’m not familiar with the method you’re wanting to use, so depending on what you formulation needs consider taking the absolute value of each component dlf.as_vector(list(map(abs, dlf.dot(dlf.grad(u1_tld), n))))

Using your component by component suggestion results in the following shape mismatch error Can't add expressions with different shapes. Traceback (most recent call last): File "mwe.py", line 114, in <module> u_n_1 = 0.5 * (dlf.dot(u1_tld, n) + dlf.as_vector(list(map(abs, dlf.dot(dlf.grad(u1_t…

abs expects a scalar since it computes the absolute value. Perhaps you’re expecting it to give you a norm of the vector, something like ufl.sqrt(ufl.dot(u, u))? I’m not familiar with the paper you’ve posted, but well aware of fluidity ’s popularity for such problems. I can’t really recommend the bes…

abs is not the issue here. There is something else in the pred1 form that is causing the error and I guess I will need to find it through term by term elimination. I’m fairly new to dolfin, ufl and DG so that is why I asked about dolfin_dg. Would it make life easier to a novice trying to code algor…

I found the culprit: jump_K1 = dlf.inner(gradu_n_1('+') - gradu_n_1('-'), jump_v) * vf1_tld * MU1 * dlf.dS This is my botched attempt at a jump function for the inner element surface integral of the stiffness matrix term K1 surface integral resulting from the IBP: vf1_tld * MU1 * dlf.inner(dlf.do…

Exception: Expecting scalar

variational formulation

nate August 2, 2021, 5:20pm 2

Can you turn this into a minimal working example? There are many missing variable definitions.

Topic		Replies	Views
How do I solve "Expecting scalar." error when defining NonlinearProblem? Errors dolfinx	1	261	March 12, 2024
Issues with vector interpolation in Navier-Stokes equations comprenssible flow General	5	134	October 7, 2024
UFLException: Invalid argument type <class 'ufl.equation.Equation'> variational formulation	6	673	March 31, 2022
UFLException : scalar integrand	3	525	April 12, 2020
Problem with creating vector with scalar function components	45	4496	June 10, 2024

Exception: Expecting scalar

Related topics