Many types of meteolorogical, environmental and boundary layer wind tunnels havebeen constructed to simulate atmospheric phenomena on buildings, structures andtransport of air pollutants. New types of 2-and 3-dimensional wind tunnels havebeen constructed in our laboratory, which have multiple-fans controlled by a computer. To simulate the required wind turbulence in the wind tunnel, each fan iscontrolled independently. First, the fan characteristics and its control methods toproduce the turbulence are discussed. Second, a few examples of longitudinal turbulent flow in the 2-D wind tunnel are presented.