Tensor operations: taking the inner product of three tensors produces a different result depending on if an intermediate variable is used

Summary

The following operations do not produce the same result for C :

1. C = A & A & A;
2. B = A & A; then C = B & A;

Steps to reproduce

Here is an example set of operations. Tensors B2a and B2b should be equal (since they are both S & S & S), but the results are different.

S = symm(fvc::grad(U));
B1 = S & S;
B2a = S & S & S;
B2b = B1 & S;

Example case

I have attached an example case and example application that writes the above two results.

What is the current bug behaviour?

A different result is produced for the two operations.

What is the expected correct behavior?

The two operations should produce the same result. I believe the second result (after using an intermediate variable) is correct mathematically. I am not sure yet what operation is being performed in the first case (S & S & S).

Relevant logs and/or images

Environment information

• OpenFOAM version : v2112
• Operating system :
• Hardware info :
• Compiler :

Possible fixes

case_0p5.zipwriteFields_test.zip