Experimental and numerical studies of turbulent flows were performed in a staggered tube bundle assuming an heat exchanger. Experimental data of axial velocity and kinetic energy of turbulence are obtained in the tube bundle by a hot-wire anemometer. The standard k-ε turbulence model was used for a microscopic numerical investigation in the tube bundle by using a Boundary Fitted Coordinate system. The microscopic numerical results reveal that the predictions of velocity, pressure drop and kinetic energy of turbulence distributions are in good agreement with the measured values or the empirical equation. As the flow is fully developed in the tube bundle, kinetic energy of turbulence remains a constant value. The effects of the inlet kinetic energy of turbulence on the development of kinetic energy of turbulence were examined in the tube bundle. The kinetic energy of turbulence in the tube bundle is not affected by the inlet kinetic energy of turbulence. The macroscopic numerical model was proposed with volume averaging and additional source terms for fluid-particle interactions. The constants in the macroscopic model were determined by conducting the microscopic calculations. As well as the microscopic results, the macroscopic numerical results show that the predictions of velocity, pressure drop and kinetic energy of turbulence are in good agreement with the measured values or the empirical equation. Therefore, the macroscopic turbulence model proposed in this study can be useful for predicting turbulent flows in the tube bundles or packed beds.