\[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}\]

\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}

double f(double t, double l, double k) {
        double r62542163 = 2.0;
        double r62542164 = t;
        double r62542165 = 3.0;
        double r62542166 = pow(r62542164, r62542165);
        double r62542167 = l;
        double r62542168 = r62542167 * r62542167;
        double r62542169 = r62542166 / r62542168;
        double r62542170 = k;
        double r62542171 = sin(r62542170);
        double r62542172 = r62542169 * r62542171;
        double r62542173 = tan(r62542170);
        double r62542174 = r62542172 * r62542173;
        double r62542175 = 1.0;
        double r62542176 = r62542170 / r62542164;
        double r62542177 = pow(r62542176, r62542163);
        double r62542178 = r62542175 + r62542177;
        double r62542179 = r62542178 + r62542175;
        double r62542180 = r62542174 * r62542179;
        double r62542181 = r62542163 / r62542180;
        return r62542181;
}

Reproduce

herbie shell --seed 2019125 
(FPCore (t l k)
  :name "Toniolo and Linder, Equation (10+)"
  (/ 2 (* (* (* (/ (pow t 3) (* l l)) (sin k)) (tan k)) (+ (+ 1 (pow (/ k t) 2)) 1))))

Timeout in 10.0m

Reproduce