Evaluation of the performance of granular fertilizer boom sprayer through computational fluid-particles-dynamid CFD simulation and scaled-down model analysis

Malaysian Agricultural Research and Development Institute (MARDI) had bought two Japanese made granular fertilizer boom sprayers to test it on Malaysia’s Paddy field. In order to confirm the local feasibility of this fertilizer applicator, they had called UTHM researchers for proper experimental and numerical evaluations. A year of experimental assessments, the conclusion was supported with full range of numerical results and has a good agreement with MARDI’s findings. In this evaluation, ANSYS CFD was used for the fluid-particles-structure simulation while the statistical and image processing were made via MATLAB software. The simulation results were verified with the results from an in-house scaled-down model which was fabricated with the ratio of 2:15. The simulation was carried out by manipulating the angles of the boom sprayer collecting plates, ranging from 32o to 120o. The length of the collecting plate, the distance of the blow head, the sizes of the fertilizer and the air velocity of the blower were also varied in order to establish the correlations between the parameters. The ambient pressure was kept at 1 atm. Even though we managed to find 60o as the optimum collecting plate angle for most fertilizer sizes, there are two major factors that made it impossible to obtain good fertilizer distribution namely; the use of mixture of three different fertilizer (Nitrogen, Phosphorus and Potassium) sizes at once and the varying velocity profiles throughout the boom sprayer

An Intuitive Control API for Catroid

In this research, the main objective is to develop an intuitive control API in Catroid to enhance its usability as a graphical programming tool for children and study the human-mobile interaction and experience made possible with this control API. Another objective is to develop this control API in open source development method and benchmark it with the typical software development method. It would greatly enrich user experience if Catroid can provide support for implementing intuitive control concepts to enhance its usability for children. But currently Catroid do not have control API support to develop intuitive user interaction with the application. In brief, an intuitive control API is missing in Catroid. Without such an API, the potential of Catroid as a programming tool cannot be unleashed. This research studies the maximization programming power of Catroid and advancement of control API in Catroid into a more intuitive form. This research studies the Open Source Development Model used to develop the control API. The scope of prototype will only covers locating direction, tilting, turning, and shaking motions as the new intuitive control made possible in Catroid The research methodology is Open Source Development Methodology (OSDM) and the Test-Driven Development Method with Extreme Programming is used for code development. The objective of OSDM is to utilize the online community who is the user and developers of Catroid to review and test source code to improve the software quality. The intuitive control API where phone sensors are integrated will further improve the user interaction and experience both in using Catroid and its application. The intuitive control API consists of sensor variables and If-Then-Else Command Block. The If-Then-Else Command Block acts as the control and the sensor variables make the control become intuitive. Accelerometer and orientation sensor are implemented in this control API where each of the sensors contributed 3 different values acted as the sensor variables: X-Sensor Acceleration, Y-Sensor Acceleration, Z-Sensor Acceleration, Azimuth, Pitch, and Roll. These sensor variables can be assigned to or removed from any text field in the Command Blocks using the Formula Editor. The usage of the intuitive control API is simple and straight forward. When a sensor variable is assigned to one of the fields in If-Then-Else Command Blocks, the intuitive control is developed. The Command Blocks in between the If-Statement Command Block and End of If Command Block will be executed whenever the logic condition in the If-Statement is true. Various intuitive user interactions could be developed depending on the creativity of users. The most popular intuitive user interactions are through locating direction, tilting, turning and shaking motions. Open Source Development Method allows developers to redefine the user requirements along with the software development which reduce the risk of software failure in the end of development

An aerodynamic analysis of a novel small wind turbine based on impulse turbine principles

This document is the Accepted Manuscript of the following article: Pei Ying, Yong Kang Chen, and Yi Geng Xu, ‘An aerodynamic analysis of a novel small wind turbine based on impulse turbine principles’, Renewable Energy, Vol. 75: 37-43, March 2015, DOI: https://doi.org/10.1016/j.renene.2014.09.035, made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License CC BY NC-ND 4.0 http://creativecommons.org/licenses/by-nc-nd/4.0/The paper presents both a numerical and an experimental approach to study the air flow characteristics of a novel small wind turbine and to predict its performance. The turbine model was generated based on impulse turbine principles in order to be employed in an omni-flow wind energy system in urban areas. The results have shown that the maximum flow velocity behind the stator can be increased by 20% because of a nozzle cascade from the stator geometry. It was also observed that a wind turbine with a 0.3 m rotor diameter achieved the maximum power coefficient of 0.17 at the tip speed ratio of 0.6 under the wind velocity of 8.2 m/s. It was also found that the power coefficient was linked to the hub-to-tip ratio and reached its maximum value when the hub-to-tip ratio was 0.45. It is evident that this new wind turbine has the potential for low working noise and good starting feature compared with a conventional horizontal axis wind turbine.Peer reviewedFinal Accepted Versio

Kriging-Based Design of Experiments for Multi-Source Exposure-Response Studies in Nanotoxicology

One of the major challenges with toxicology studies of nanomaterials (NMs), compared to traditional materials or chemicals, lies in the large NM variety (or sources) caused by their various physico-chemical properties. How to efficiently design multi-source biological experiments for the toxicity characterization of NMs in terms of their exposure-response profiles? This work intends to address this question by a two-stage experimental design procedure, which is developed based on the statistical model, stochastic kriging with qualitative factors (SKQ). With a given experimental budget, the SKQ-based design method aims at achieving the highest-quality SKQ, which synergistically models the exposure-response data from multiple sources (e.g., NM types). The method determines the experimental design (that is, the sampling location as well as allocation) in such a way that the resulting sampling data allow SKQ to realize its maximum potential to pool information across multiple sources for efficient modeling. Built in a two-stage framework, which enables a learning process of the target exposure-response relationships, the SKQ-based design procedure also inherits the general advantages of stochastic kriging in the sense that the design is particularly tailored to model the possibly nonlinear and complex relationships and heterogeneous data variances. Through simulation studies, the efficiency of the SKQ-based procedure for multi-source experiments is demonstrated over the two alternative design methods

On the turbulent flow models in modelling of omni-flow wind turbine

Yong Chen, Pei Ying, Yigeng Xu, Yuan Tian, 'On the turbulent flow models in modelling of omni-flow wind turbine', paper presented at The International Conference on Next Generation Wind Energy (ICNGWE2014), the Universidad Europa de Madrid, Madrid, Spain, 7th-10th October 2014.The computational fluid dynamics (CFD) has a wide application in the wind energy industry. In CFD simulations, a turbulence model plays a significantly important role in accuracy and resource cost. In this paper, a novel wind turbine, omni-flow wind turbine, was investigated with different turbulence models. Four turbulence models, standard k-ε, realizable k-ε, standard k-ω and SST k-ω models, were employed for this wind turbine in order to assess the best numerical configuration. The performance of these four turbulence models was validated with wind tunnel tests. It is evident that the realizable k-ε turbulence model is most suitable to simulate this novel wind turbine