Performance of selected agricultural spray nozzles using particle image velocimetry

The aim of the present study was to investigate the influence of nozzle configurations on spray drift and explain the influences using several atomization characteristics (length of spray sheet, spray angle, velocity distribution of flow field, fluctuation of velocity, and droplet size). Nozzles manufactured by one company (Lechler GmbH, Germany) were tested by spraying local tap water in a wind tunnel at an operating pressure of 0.3 MPa and under room temperature. The nozzles tested were compact air-induction flat fan nozzles (IDK120-02, IDK120-03), standard flat fan nozzles (ST110-02, ST110-03), and hollow-cone swirl nozzles (TR80-02, TR80-03). The atomization process was recorded using a Particle Image Velocimetry (PIV) system, droplet size was measured by a Sympatec Helos laser-diffraction particle-size analyzer, and spray drift was evaluated in a wind tunnel with deposition measured using a calibrated fluorometer (Turner-Sequoia model 450). Results showed that spray drift was significantly different among nozzle types (

A comparative analysis on the velocity profile and vortex shedding of heated foamed cylinders

The flow pattern behind a circular cylinder is associated with various instabilities. These instabilities which are characterized by the Reynolds number (Re) and include the wake and vortices detached from it are well-studied in the past. However, the effect of heat transfer on these stabilities needs more attention. Moreover, depending on the physical application of the cylinder, increasing the level of turbulence on the surface of the cylinder could be a target for pressure drop reduction or heat transfer enhancement. Hence, hotwire anemometry has been carried out to investigate the velocity profile and vortex shedding from a heated foamed cylinder. The experiments are performed for a range of Reynolds numbers from 1000 to 10000 based on mean air velocity (0.5, 1 and 2 m/s) and the cylinder outer diameter (0.042, 0.062 and 0.072 m) at three different cylinder surface temperatures being ambient temperature, 50°C and 75°C

The proper orthogonal decomposition in the analysis of the wake behind a foamed and a finned circular cylinder

Particle Image Velocimetry (PIV) has been carried out to investigate the wake region behind a foamed and a finned cylinder. The purpose of this analysis is to develop one- and twopoint correlations and to investigate the flow characteristics for these two cases. The experiments are conducted for two Reynolds numbers (based on the mean air velocity and the cylinder diameter) 2000 and 8000. Two dimensional results of planar PIV reveal the important aspects of the local flow features of the circular finned and foamed cylinders. These include turbulent boundary layer development over the surface and a delayed separation of the flow resulting in a smaller wake size in each case. The application of Proper Orthogonal Decomposition (POD) to the PIV velocity fields of the two cylinder types is also discussed. The POD computed for the measured velocity fields for both cases shows that the first two spatial modes contain most of the kinetic energy of the flow irrespective to the cylinder type. These two modes are also responsible for the large-scale coherence of the fluctuations. For two different cylinder types, the first four eigenmodes of the flow field were calculated and their structures were analyzed. The first four eigenmodes reveal the details about the global mean flow structure, with the largescale structure being mainly related to the most energetic flow motion

On using Monte-Carlo tree search to solve puzzles

Abstract Solving puzzles has become increasingly important in artificial intelligence research since the solutions could be directly applied to real-world or general problems such as pathfinding, path planning, and exploration problems. Selecting the best approach to solve puzzles has always been an essential issue. Monte-Carlo Tree Search (MCTS) has surged into popularity as a promising approach due to its low run-time and memory complexity. Thus, it is required to know how to employ this method to solve the puzzles. In this work, we study the applicability of MCTS in solving puzzles or solving a puzzle with MCTS, not comparing many MCTS approaches. We propose a general classification of puzzles based on their features. This classification consists of four primary classes that provide a mathematical formula for each and their satisfactory criteria. This classification let us know how to utilize MCTS based on the puzzle’s features. We pass each puzzle to an MCTS algorithm as a series of satisfaction functions based on this mathematical formulation. The classification can perform general pathfinding or path-planning if the outlining problem is defined within the described mathematical constraints. MCTS progressively solves a puzzle until the functions are completely satisfied in our proposed classification. We examine different puzzles for each class using our proposed methodology. Furthermore, to evaluate the proposed method’s performance, each of these puzzles is compared with their available SAT solvers using the Z3 implementation and different variations of MCTS that are generally used