[saumavadey]

Are the modified Bessel Functions of Type 1 and Type 2 ie. I0, I1 and K0, K1 are available inside OpenFOAM's latest version (OpenFOAM v2006)?

[dlahaye]

OpenFoam has boost (see boost.org) and boost in turn has modified Bessel fcts.

[saumavadey]

Hello dlahaye!

Thank you very much for your answer.

As I am a beginner in OpenFOAM programming, can you please guide me through the steps to call any function from 'BOOST' to my code in OpenFOAM.

Do I need to install the latest version of BOOST in the same directory where I have OpenFOAM installed on my laptop?

[dlahaye]

See examples on boost.org Good luck.

[saumavadey]

Hello Foamers!

I have stated using the Modified Bessel Function from boost in my code as follows:

scalar T = this->db().time().value();
scalar P = i*log(2.0)/T;
scalar Q0 = sqrt(P);
scalar K0_0 = cyl_bessel_k(0, Q0);

While compiling it gives the following error:

error: ‘cyl_bessel_k’ was not declared in this scope scalar K0_0 = cyl_bessel_k(0, Q0);

note: suggested alternative: In file included from myFunctionFvPatchScalarField.C:18:0: /usr/include/boost/math/special_functions/bessel.hpp:587:81: note: ‘boost::math::cyl_bessel_k’
inline typename detail::bessel_traits<T1, T2, policies :: policy<> >::result_type cyl_bessel_k(T1 v, T2 x)

I am not being able to figure out the problem. I seek help in this regard.

[Esmaeelef]

Hello everyone,

I have seen that OpenFOAM provides bessel functions of orders 0 and 1, but, I need to use a Bessel function of non-integer order in my code. Does OpenFOAM have a function in this regard?

[saumavadey]

I have seen examples of Bessel function evaluation of non-integer orders using the Boost library functions. You can try using them.