International Journal of Hydromechatronics (5 papers in press)

Regular Issues

• Intelligent selection of parameters for air-floating piston based on improved multi-objective grey wolf optimisation algorithm  
  by Yifan Jia, Shu Qian, Zhihao Zhang, Hengyang Zhou, Lijiao Liu, Xiang Li, Luis Miguel Ruiz Páez, Pengfei Qian 
  Abstract: The air-floating piston serves as the core component of an air floating frictionless cylinder, which significantly impacts the cylinder's performance. However, since the radial bearing force and gas consumption of the piston are influenced by numerous factors, designing a piston with excellent performance through numerical simulation and empirical data is impractical. For this reason, a design method of air-floating piston is proposed to intelligently select the parameters of the piston using intelligent optimisation algorithm. To achieve efficient parameter selection, mathematical models are developed for bearing capacity and gas consumption. In view of the weaknesses of the multi-objective grey wolf optimiser (MOGWO) such as imbalance between exploration and exploitation, poor local search capability, an enhanced approach which integrates the golden sine algorithm, chaotic mapping, and t-distribution mutation is proposed. The appropriate parameters of the piston are selected to machine the prototype from the Pareto optimal solution. The test results indicate that the designed air-floating piston exhibits excellent performance.
  Keywords: air-floating piston; multi-objective grey wolf optimisation algorithm; golden sine algorithm; chaotic mapping.
  DOI: 10.1504/IJHM.2024.10069178
   
  
• A review on preparation, characterisation and applications of microencapsulated phase change material slurries for thermal fluid and energy systems  
  by G.V.N. Trivedi, Rohan Barbade, R. Parameshwaran 
  Abstract: Microencapsulated phase change material slurries are the functional fluids that have emerged as a prominent energy-saving solution in thermal fluid and energy systems (TFES). These functional fluids, being in the state of flow, can enhance the thermal energy storage capacity of the compared to carrier fluid. The remarkable advantages of these fluids are currently being investigated for utilisation in engineering applications. The review articles written so far have concentrated on the preparation, characterisation and heat transfer studies, and lack comprehensive information regarding applications in TFES. This paper gives a comprehensive review of efforts made by the researchers in investigating these fluids in buildings for heating/cooling requirements, electronic systems, and biomedical and PV-thermal applications. In addition to this, this review also discusses studies pertaining to the thermo-physical and rheological properties of slurries. Some limitations have been put forward to provide direction for future studies.
  Keywords: thermal energy storage; TES; phase change materials; microencapsulated phase change material slurries; thermophysical; rheological properties.
  DOI: 10.1504/IJHM.2025.10068551
   
  
• Nonlinear nominal modelling of proportional valves with unknown spool displacements  
  by Teruo Kato, Satoru Sakai, Ryo Arai 
  Abstract: The paper discusses a new nonlinear nominal modelling for a proportional valve for which the spool displacement is unknown. First, we introduce a nonlinear nominal model of the hydraulic cylinder dynamics. Next, we propose a new nonlinear nominal modelling consisting of two procedures. In the first procedure, by applying a previous estimation method using a servo valve, several physical parameters of the valve, such as the damping, are identified. In the second procedure, by applying the previous estimation method using the hydraulic cylinder as a flow rate sensor and also multiplying the spool motion equation by the unknown flow gains, the unknown parameters are identified by the projection theorem. The effectiveness of the proposed method is confirmed by an experimental proportional valve, which is an electronic control modulation valve (ECMV). The identified nominal model outputs and the experimental outputs are sufficiently similar.
  Keywords: proportional valves; nonlinear nominal modelling; parameter identification; hydraulic cylinder dynamics; unknown spool displacements.
  DOI: 10.1504/IJHM.2025.10070319
   
  
• Experimental investigation of hygrothermal ageing on fracture and crushing behaviour of fibre reinforced composite structures  
  by Sandiri Devaraj, Y.B. Sudhir Sastry, P.R. Budarapu 
  Abstract: An experimental investigation of hygrothermal ageing on the fracture toughness of glass fibre reinforced composite structures has been investigated. Double cantilever beam (DCB) and pipe specimens were immersed in an insulated tank filled with saline water, and thermally aged with the help of an electric heater and a micro-controller, at temperatures of 100°C, 80°C, 60°C and 40°C for six hours. In order to study the delamination, crack growth experiments were conducted on the composite DCB specimens to capture the load-displacement curves. The experiments were extended to estimate the compressive strength of the composite pipes of diameters 50 mm, 75 mm and 100 mm, respectively. As compared to the virgin specimen, the fracture toughness of laminated composite specimens with initial notch is observed to drop by 83.88%, as well as the compressive strength of pipe size 50 mm is observed to reduce by 21.5% when the temperature is raised to 100°C.
  Keywords: fibre reinforced composite laminates; composite pipes; hygrothermal ageing; mode-I crack growth experiments; crushing strength.
  DOI: 10.1504/IJHM.2024.10069542
   
  
• Investigation into the thermal optimisation of low eddy current structure of high-speed on/off valve considering energy consumption and dynamic characteristics  
  by Yuzheng Li, Shaoxian Deng, Niansheng Wang, Heng Du, Hui Huang 
  Abstract: In this paper, the coupling characteristics between various physical fields of HSV are analysed by combining theoretical research and numerical simulation, and the laws of heat generation, temperature rise, and dynamic characteristics are revealed. The low eddy current slit structure is further designed to solve the problem of serious heat generation in the HSV, and the multi-objective thermal optimisation is carried out for the number of slits, the width and the depth of slits of the slit structure by taking into account of the energy consumption and the dynamic characteristics through orthogonal experiments. The results show that the response time of the low eddy current slit structure is shortened by 0.9 ms, a decrease of 5.42%, and the coil temperature rise is reduced by 89°C, a decrease of 37.24%, compared with that of the original structure under the three-voltage, 250 Hz driving mode.
  Keywords: high-speed on/off valve; HSV; energy consumption; dynamic characteristics; thermal optimisation.
  DOI: 10.1504/IJHM.2025.10069812