In this work we investigated the fluid dynamics in a pilot-scale bubble column equipped with an asymmetric "tree" type sparger at superficial velocities between 0.01 and 0.37 m s(-1). We present an extensive experimental data set consisting of overall holdup measurements, liquid velocity, gas velocity, and local gas volume fraction profiles as well as bubble size distributions. The second part of this work examines the modeling of the column using computational fluid dynamics (CFD). It is found that the computationally efficient single bubble size model used in this work offered satisfactory predictions of the complex flow patterns found inside bubble columns operated in the industrially relevant heterogeneous flow regime.