Unmanned aerial vehicles has been gaining more attention in recent years in the agriculture field. Employment of the Unmanned Aerial Vehicles in agriculture field is to enable the operation related to crop monitoring and crop protection. Crop protection in agriculture field is enabled by employing the UAV spray as automated application. UAV spray carries fertilizer or pesticide. However, spray drift of the UAV is considered as major impact of the agriculture drones. In addition, various spray factors such as velocity, speed, height, orientatation of the nozzle play significant role in spray quality of the agriculture drone. In this paper, computational fluid dynamic model for designing optimal flow characteristic of spraydroplet at optimal velocity and orientation is designed and simulated in this work for effective spray deposit in the particular environment without losses