Recent Patents on Engineering - Volume 12, Issue 3, 2018

Background: The research on the wake will benefit the efficiency of wind turbines and the arrangement of wind turbines in wind power plant. It is an important subject of research in recent years, and the research on the wake of the vertical axis wind turbine is still at the exploratory stage. In the process of wake study, the classic Jensen wake model was proposed by Danish scientist N.O. Jensen in the 1980s. Objective: In order to make a pave for further flow analysis and arrangement of multiple wind turbines. The patent of the Senegal-type vertical axis wind turbine studied in this paper was introduced and analyzed in detail. The patents of wake effect and the vertical axis wind turbine with other structures were also introduced and analyzed. A novel method of wake analysis was proposed for a Senegal-type vertical axis wind turbine (VAWT) based on improved Jensen wake model. Methods: The wake parameters of the vertical axis wind turbine were analyzed combined with flow field analysis of ANSYS CFX software, and the numerical simulation of the novel wind turbine was carried out. Results: The variation of wind speed, pressure, eddy viscosity, turbulent kinetic energy and turbulent dissipation rate was studied, and the results of the three-dimensional distribution of the wake parameters such as wind speed and pressure were derived. Conclusion: The accuracy of the improved Jensen wake model was verified by the analysis of the wake parameters and the results show that the downstream of the VAWT produces a great wind velocity deficit, and the flow of the wind turbine on the downwind side is turbulence.

Background: Chitosan is an eminent biopolymer which has the -OH and -NH2 groups on its surface. Chitosan in its raw form has some limitations. Hence, to increase its efficiency for taking up the contaminants, it can be modified using different chemicals. Lead is the one amongst all toxic elements on the earth. Despite its toxicity, it is very much used in the industrial processes related to our daily life. As a consequence, lead is present in soil, water, and air. Objective: This paper focuses on the reviewing of the research papers and patents published on the removal of lead from aqueous environment using modified form of chitosan. The reports which recently came up to make this polymer even more attractive to the researchers are also included in the present review paper. Methods: The adsorption studies and patent technologies reported on lead removal using chitosan and its altered forms are explained in this study. Conclusion: The simple alterations, either physical or chemical, in the structure of chitosan can bring the tremendous change in its properties. These changes can be applied in different fields for the benefit of the mankind and for environment. In the present review paper, adsorption of Pb2+ from aqueous solutions using chitosan and its derivatives has been extensively studied. It will be helpful in finding out the possibilities of preparation of new biocomposites by modification of chitosan.

Background: In the five-axis milling process of aviation integral impeller, the cutter axis vector is changed dramatically. It leads to marks on the finished surface, even the damage of it, and the chatter is easy to occur. So the machining precision is difficult to guarantee. Objective: For solving this problem, a research on five-axis NC simulation and parameter optimization for aviation integral impeller was carried out. Methods: A new method used for the parameter optimization is proposed, which considers the collision and chatter at the same time. Firstly, a NC simulation environment was created in the VERICUT, which can achieve the geometry simulation of specific process system. This can effectively avoid the collision among the machine spindle, cutting tool, worktable and fixture. Then, using the dynamic simulation software cutpro9.0, the hammer test and stability domain simulation were conducted under a given radial cutting depth (cut width). The stability region expressed by spindle speed and axial cut depth was obtained. The machining time was taken as the optimization objective, and cutting depth, spindle speed, feed per tooth were taken as the experimental factors, an orthogonal experiment of three factors and four levels was designed. The cutting time can be gained through geometry simulation. Based on the range analysis, the machining parameters for shorter time were given. The optimization results were validated by cutting experiment. Besides, a lot of patents on five-axis NC machining and parameter optimization were studied. Results: The results show that the proposed method can promote the efficiency of rough machining of aviation integral impeller, and the quality of finished surface can be ensured too.

Background: Bubbly flows can frequently be seen in engineering fields such as fermentation reactions, floatation of minerals, drag reduction by bubbles, etc. The physical parameters often change in industrial processes, so it is important to conduct extensive studies on the influence of gas- and liquid- phase parameters on the liquid turbulence. Objective: The extensive studies are performed on the liquid turbulence modulation by bubble injection with change of bubble velocity, gravity magnitude and considering bubble coalescence, and some physical laws on liquid turbulence flow laden with bubbles are applied to guide the design of patents on the drag reduction system by bubbles. Methods: The bubbly turbulent flows are investigated with the numerical method, the mixture model is chosen as the multiphase flow model, and the velocity field of the turbulent flow is solved by Reynolds stress model. Results: The present results show that the bubble velocity has the very little influence on the liquidphase turbulence; the gravity magnitude has the definite influence on the liquid-phase turbulence, and the influence of the bubble injection on the liquid-phase turbulence under normal gravity is far greater than that under microgravity. In addition, only when the bubble volume fraction is sufficiently high, the bubble coalescence has the significant influence on the liquid-phase turbulence. Conclusion: The influence of gravity on the bubble distribution and the liquid-phase turbulence is important, and the bubble coalescence causes the definite influence on the liquid turbulence modulation when the bubble volume fraction is high enough.

Background: The cracking load is an important parameter in the design and testing of beam structures according to the recent patents. Compared to ordinary concrete, recycled aggregate concrete components are more prone to cracking. Methods: In this paper, the calculation method and the size effect of the cracking load for the recycled aggregate concrete beam were studied. Four recycled aggregate concrete beams with different sizes were tested by the four-point bending experiment to obtain their cracking loads. According to the comparison of the tested values and the calculated values by two existing methods, it was found that the existing calculation methods are only suitable for small-sized beam specimens. The main reason for the calculation error lies in the fact that the existing calculation method does not consider the size effect of tensile strength of recycled aggregate concrete. Results: It is very necessary to modify the existing formulas to calculate the cracking load more accurately for large-size beam specimens. Therefore, this paper presents an improved formula for the cracking load calculation by considering the size effect. The calculated results obtained by the proposed method are closer to the test values than those obtained by the original methods. Conclusion: It has been shown that it is necessary and reasonable to consider the size effect in the calculation of the cracking load of the recycled aggregate concrete beam.

Background: Dissolved Gas Analysis (DGA) is an effective method to detect the potential fault of oil immersed transformer, while the ratio method based on DGA technology has some defects. Objective: This study aims to timely comprehend the transformer condition and accurately predict the incipient fault. Methods: By investigating the recently published papers and patents relating to transformer fault diagnosis, a novel diagnosis model based on the enhanced cuckoo search algorithm combined with BP neural network (ECSBP) is designed. In the proposed approach, the adaptive adjustment strategy of step size is employed to enhance the convergence rate and solution quality. Furthermore, the dimension by dimension improvement mechanism is also utilized to balance the exploration and exploitation. Subsequently, the transformer fault diagnosis model using ECSBP approach is built. Results: By evaluating the optimization performance on a set of benchmark functions, the enhanced cuckoo search algorithm is apparently superior to the original CS and its 2 variants. Simultaneously, compared with the other 4 transformer fault diagnosis models, ECSBP method has the highest diagnostic accuracy. Conclusion: The proposed ECSBP model integrates the advantages of artificial intelligence and DGA technology, and then can be used in the fault diagnosis of power transformer.

Background: Needle insertion is commonly used in minimally invasive surgery. Cannula flexible needle, as one of the insertion needles is composed of a flexible cannula and a flexible stylet, both of which need to be driven independently. The coordination control of both motions can achieve a variety of 3D insertion paths according to recent patents. Objective: This paper is to innovatively design an insertion mechanism for the cannula flexible realizing the coordinated motions of both the cannula and the stylet. Methods: Based on the analysis of the required degrees of freedom and motion models of the cannula flexible needle, the general scenario of the insertion mechanism was designed by using TRIZ theory. The condition for achieving the linear insertion path was obtained based on the analysis and calculation of the screw motion by using the screw theory. Results: The general scenario of the insertion mechanism was innovatively obtained, the spiral slide and the cross linear slide were adopted, and furthermore, the parameters of the spiral slide were determined, along with the design of cross linear slide. At last, the virtual prototype was achieved. Conclusion: In this paper, the TRIZ theory was used to innovatively design an insertion mechanism for the cannula flexible needle, and both the general scenario and the concrete parts were achieved. The result showed rationality of the designed insertion mechanism fulfilling all the requirements for the cannula flexible needle.

Background: Diamond is a precious stone and is considered as a safe investment, provided purchased from a trustworthy certified brand. The buyer should be very much cautious in purchasing precious stones and therefore needs decision making skills. The selection of a diamond depends on various factors like shape and 4C's: Cut, color, clarity, carat weight. Every buyer is not aware of these factors. A customer has no choice to rely on the brand. Objectives: In this paper, we proposed a model for the selection of diamond among various brands. The model presents a detailed review for the analysis and the design of decision making process. The process can be patented for further application in other domain of research. Methods: We develop a hypothetical case study based on the information about customers, available jewellery brands and their factors, which affects the purchase of the diamond with assigned degree of membership, non- membership and hesitation index by using one parametric Tsalli's entropy measure for various values of the parameter (α) under intuitionistic fuzzy environment. Results: For various values of parameter (α), different decision values have been discussed as explained in Tables (6-13). Conclusion: From the tables, it is concluded that the customers 1 c and 3 c can purchase a diamond of the brand 2 b , customer 2 c can purchase a diamond of brand 1 b and customer 4 c can purchase a diamond of brand 4 b . The proposed model can be applicable to other decision making problems.

Background: Wearable power assist robot is a new type of electromechanical integration device designed to imitate the biological exoskeleton. The device can be worn by the user, providing the user with body support, movement assistance and power-assisted functions. In recent years, patents suggest that wearable assist robots have been widely used in the field of human limb rehabilitation. The patients can use the robot to carry out effective functional rehabilitation training and achieve the goal of promoting limb function recovery and improving activities of daily living. Objective: Based on clinical rehabilitation medicine theory, and aiming at helping the patients with hemiplegia, a 7-DOF wearable rehabilitation robot for an upper limb is designed. Methods: Three-dimensional model of the rehabilitation robot is created in Pro/E. According to D-H transformation, the kinematics model is established. Kinematics simulation is carried out by the Matlab programming. Results: Both of the forward and inverse analysis of kinematics are presented. The wrist centroid curves of displacement, velocity and acceleration are obtained, respectively. The results prove that the movement of the robot is smooth and the robot scheme is feasible. Conclusion: The structure design and motion analysis process of the robot can provide a reference for other wearable limb rehabilitation device.

Background: Windblown sand mitigation for civil structures in arid environment is crucial. Indeed, the number of railways crossing deserts and arid lands is increasing. A number of sand mitigation measures already exist. Among them, sand barriers are particularly intended for line-like infrastructures. We reviewed patented sand barriers on the basis of their shape and porosity. Objective: A new solid barrier for windblown sand mitigation called Shield for Sand is presented. Shield for Sand has been designed with the aim of maximizing the sand trapping efficiency through an upper windward deflector and simplifying its maintenance by complaining to sand removal machines. The development of Shield for Sand follows the path traced by the Technology Readiness Level scale. Methods: The preliminary design of Shield for Sand has been supported by computational simulations of the wind flow around the barrier. Then, Shield for Sand has been tested in a wind tunnel with drifting sand in order to assess its efficiency. Both computational and experimental approaches allow an increase of the Technology Readiness Level. Results: The reversed flow induced by Shield for Sand increases its sand accumulation potential with respect to similar existing sand mitigation measures, such as the straight vertical wall. The efficiency of Shield for Sand resulting from the wind tunnel test is very high and almost constant with increasing sand accumulation level. Conclusion: The Shield for Sand working principles and performances are confirmed excellent. Final fullscale in-situ experiments are necessary to test the barrier under real environmental operational conditions.