Simulation Mode Research Articles

Lightweight steering equipment based on prestressed modal analysis

As the key component to control the driving direction of the vehicle, the steering device always bears large vibration and load. In order to improve structural performance and reduce costs, a multi-objective optimization method based on the results of prestressed modal analysis was proposed, which can achieve significant lightweight and cost-effectiveness improvement. Based on the principle and working characteristics of the steering device, the minimum value of mass, minimum value of maximum stress, maximum value of equivalent stiffness were set as optimization objectives. Through finite element analysis, the prestressed modal module was constructed, and the strength and modal characteristics of the steering device were obtained. In order to verify the accuracy of prestressed modal analysis, the vibration testing experimental platform was built in a non free state. The excitation and response signals can be obtained through sensors and data acquisition devices and used as input and output data. According to the comparative analysis of simulated vibration modes, it can be concluded that the coupling analysis of strength and mode is more in line with actual boundary conditions and has high reliability. The DOE (Design of Experience) method was adopted to construct discrete corresponding values between design variables and optimization objectives based on the results of prestressed modal analysis. In order to better evaluate the cost-effectiveness of lightweight, a comparative analysis was conducted on the results of primary and secondary lightweight. The results show that the prestressed modal analysis method can achieve good dynamic analysis accuracy. Without reducing strength and equivalent stiffness, the mass of the steering device can be reduced by 14 %, achieving high economic benefits.

Oxygenated bio-fuel synthesis in reactive distillation: A technological reform under process intensification

Chemical Engineering processes demands separation of reaction products to obtain them in purest form. Reactive Distillation facilitates this feature by incorporating a reactive zone for reaction between conventional rectifying and stripping zone for distillation. It also aid for solid catalyst incorporation of amphoteric nature to avoid repetitive addition of catalyst for different experimental run and will also improve the product yield. The other beneficial features of Reactive Distillation include reduced synthesis cost, reduced utility space required and higher selectivity. This technique is introduced in this paper for synthesis of oxygenated bio-fuel. For this, fuel additive of ether family namely Tert Amyl Ethyl Ether (TAEE) is synthesized using ethanol. Similarly, Biodiesel synthesis is done using transesterification of waste cooking oil with methanol. Both fuel-oxygenate (TAEE) and biodiesel are then blended in varying proportion to improve ignition quality of biodiesel fuel. The study is done experimentally and analyzed under object oriented modeling mode in simulation. Optimization of synthesis process is done using revamping in experimental mode corresponding to sensitivity analysis in simulation. The congruence results show that purity of 95 % and 65 % for biodiesel and TAEE respectively is obtained in reactive distillation corresponding to reboiler duty of 2 kW and reflux ratio 4.

Identifying Alfvén wave modes in the solar corona

Context. Oscillations are observed to be pervasive throughout the solar corona, but it remains challenging to positively identify different wave modes. Improving this identification would provide a powerful tool for investigating coronal wave heating and improving seismological inversions. Aims. We aim to establish whether theoretical methods used to identify magnetohydrodynamical wave modes in numerical simulations can be employed on observational datasets. Methods. We applied wave identifiers based on fundamental wave characteristics such as compressibility and direction of propagation to a fully 3D numerical simulation of a transversely oscillating coronal loop. The same wave identifiers were applied to the line-of-sight integrated synthetic emission derived from the numerical simulation data to investigate whether this method could feasibly be useful for observational studies. Results. We established that for particular line(s) of sight and assumptions about the magnetic field, we can correctly identify the properties of the Alfvén mode in synthetic observations of a transversely oscillating loop. Under suitable conditions, there is a strong agreement between the simulation and synthetic emission results. Conclusions. For the first time, we have provided a proof of concept that this theoretically derived classification of magnetohydrodynamic wave modes can be applied to observational data.

Numerical Analysis Study on Seismic Performance of Semi-Rigid Steel Frame Infilled with Prefabricated Composite Wall Panels

The semi-rigid connected steel frame has good displacement ductility and energy dissipation capacity, and the interaction between the traditional steel frame and the filled wall is the critical factor affecting its seismic performance. In this paper, for the semi-rigid steel frame, the composite wall panel and the frame are separated by foam concrete mortar, and the effective connection is achieved by the tensioned steel bar. The premature brittle failure of composite wall panels can be prevented using friction energy dissipation between wall panels. By using ABAQUS simulation method, a semi-rigid steel frame composite wall is established. The failure mode, hysteresis curve and skeleton curve of simulation and test are compared and analyzed, and the reliability of the model is proved. The finite element model with the different number of wall panels is established to analyze its influence on the seismic performance of the structure. The results show that the frame structure realizes the effective connection between the composite wall panel and the concrete-filled steel tube frame, which jointly resists the earthquake action and reduces the damage of the earthquake action to the filled wall. With the increase in the number of composite wall panels, the ultimate load decreases gradually. The initial stiffness of the four layers of wall panels is more significant and decreases rapidly. When the wall panel has three or four layers, the energy dissipation capacity of the specimen is the strongest. The two are relatively close, stable at 24.48, and the increase is 5.15% compared with the second layer of the wall panel, and the increase is 12.72% compared with the third layer of the wall panel.

Wearable MXene‐Graphene Sensing of Influenza and SARS‐CoV‐2 Virus in Air and Breath: From Lab to Clinic

AbstractThe rapidly expanding severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and its variants demand a continuous monitoring method through portable and wearable devices. Utilizing the rich surface chemistry and high chemical‐to‐electrical signal conversion of 2D MXene‐graphene heterostructure thin films, a field‐effect‐transistor (FET) sensor, which has a flexible substrate to be assembled onto the mask and combines with a Bluetooth system for wireless transmission is developed, to detect the influenza and SARS‐CoV‐2 viruses in air and breath. At first, the developed sensors are examined in the laboratory through direct contact with sensing targets in solution form. The results show a low limit of detection (LOD) of 1 fg mL−1 for recombinant SARS‐CoV‐2 spike protein and 125 copies mL−1 for inactivated influenza A (H1N1) virus with high specificity in differing recombinant SARS‐CoV‐2 spike protein and inactivated H1N1 virus. Then the sensors are tested under various simulated human breathing modes through controlled exposure to atomizer‐generated aerosols in an enclosed chamber and mask coverage. The results show the high sensitivity of the developed sensors under varying distances to the source, viral load, flow rate, and enclosed conditions. At last, clinical tests are carried out to demonstrate the robustness and potential field applications of the sensors.

A Numerical Study on the Large Displacement in Functionally Graded Beam under Thermal Effect

The large displacement behavior of a Functionally Graded (FG) beam under uniform thermal load is investigated numerically. Six different effects are taken into consideration when examining the large displacement behavior of the beam. These are the effects of temperature, material, geometry, slenderness, force, and boundary condition. The nonlinear numerical analysis is carried out by using the Simulation mode of SolidWorks, which is a finite element-based commercial program. As a result, the displacement of the end of the beam increase with increasing temperature, slenderness ratio, and force. However, it decreases with increase in the ratio of ceramic in Functionally Graded Material (FGM) and the width of the beam. Moreover, as expected, the maximum and minimum displacements are obtained in the beams with Clamped-Free and Clamped-Clamped boundary conditions, respectively.

Empirical Equations for Modelling Yarn–Mortar Debonding in TRM-Strengthened Masonry Walls Subjected to Out-of-Plane Loading

The effectiveness of textile-reinforced mortar (TRM) strengthening of masonry walls largely depends on the bond between the constituent materials. Finite element analysis (FEA) can provide valuable insights on the effect of the parameters affecting the bond; however, detailed FEA is computationally intensive. To alleviate this, we develop novel empirical equations to estimate effective textile fibre properties, thus implicitly accounting for yarn and mortar debonding. As a result, 3D finite element simulations of strengthened wall specimens are simplified and accelerated. The proposed scheme is calibrated using load–displacement paths derived from experimental data, and the simulated failure modes are compared against the experimental ones demonstrating perfect agreement. A parametric analysis is conducted, exploring the impact of the mechanical ratio of TRM reinforcement and the axial wall load on the effectiveness of TRM strengthening. We demonstrate that low values of mechanical reinforcement, corresponding to natural fibres, give rise to an 8-fold increase in the capacity of unreinforced walls. The findings draw conclusions about the efficacy of TRM strengthening in masonry structures, and provide valuable insights for optimising TRM reinforcement, considering different fibre materials and axial loads in masonry structures.

Coordination Structure of Si(II) Ions in Binary Melts (LiF-KF, LiF-NaF, and NaF-KF) and Ternary Melt (LiF-NaF-KF).

The formation of Si(II) by the comproportionation reaction between electrodeposited silicon and Si(IV) ions [Si(IV) + Si0 ⇄ 2Si(II)] in fluoride melts has been discussed in many previous reports on the electrochemical processing of silicon. In this study, the coordination structure of Si(II) ions in LiF-KF, LiF-NaF, NaF-KF, and LiF-NaF-KF melts was investigated by high-temperature Raman spectroscopy and quantum chemical calculation based on density functional theory. The formation of Si(II) ions was induced by mixing metallic silicon powder as the source of Si0, with the melts containing hexafluoro silicate or silicon dioxide as the source of Si(IV) ions. The simulated vibrational modes of the Si(II) species and the experimental Raman bands showed good agreement. It was found that both Si(II) and Si(IV) species were detected in either fluoride melt, demonstrating that the proposed comproportionation reaction between Si0 and Si(IV) occurred. In addition, the interaction between Si(II) and F-, O2-, Li+, Na+, and K+ ions significantly changed depending on the composition of fluoride melts. The coordination structure of the Si(II) ions reported in this study will provide clues for controlling the electrodeposition process of silicon in fluoride melts.

Numerical and experimental research on axial injection end-burning hybrid rocket motors with polyethylene fuel

This study investigates the end-burning hybrid rocket motors with polyethylene fuel by the numerical simulation and experiment. Based on computational fluid dynamics, a numerical model is developed. The model is validated by two firing tests in this hybrid rocket motor, which uses oxygen and polyethylene as propellants. The results show that the numerical and experimental data are in good agreement, and the error of the chamber pressure is less than 2.63%. Based on the simulation mode, the blowoff limit of the end-burning hybrid rocket motors is investigated. When the nozzle throat diameter and the inner diameter of grain are large, it is more difficult for the hybrid rocket motor to achieve end-burning mode, i.e., the flame spreading is prevented in the narrow duct. The main reason is that when the nozzle throat and the grain port are large, chamber pressure and oxidizer flow velocity are low. Therefore, the friction velocity considering the pressure and flow velocity is proposed. The critical friction velocity is about 4.054–4.890 m/s in the hybrid rocket motors. When the friction velocity exceeds the critical friction velocity, the combustion mode in hybrid rocket motors changes from the flame spreading mode to the end-burning mode. Moreover, the regression rate formula is obtained by fitting, which shows that the regression rate has a good correlation with combustion chamber pressure. The critical friction velocity and regression rate formula can provide an important reference for end-burning hybrid rocket motors.

USER IMPLEMENTATION AND ASSESSMENT OF BDS-3 PRECISE POINT POSITIONING AUGMENTATION SERVICE WITH NO ECONOMIC COST

Abstract. The satellite-based precise point positioning (PPP) service enables users with high accuracy positions without Internet connections. Currently, two types of satellite-based PPP services are available. One type is commercial service, such as Trimble CenterPoint RTX service. The second type is non-commercial and cost-free service, including the BDS-3 satellite-based PPP service based on PPP-B2b signals. This service is currently open access to all receiver manufacturers. This contribution firstly presents a detailed instruction on how to apply PPP-B2b signals into positioning. Afterwards, the performance of BDS-3 PPP service is validated with both static and kinematic experiments carried out in Wuhan, China, during day of year 168 and 172, 2022. Results indicate that PPP-B2b signals mainly improve BDS-3 clock precision and GPS orbit accuracy. With BDS-3 PPP-B2b augmentation messages, the static satellite-based PPP shows 3.9/6.9/10.3 mm daily solution repeatability in E/N/U directions, respectively. An average of 13.9 min convergence time and 3.42/2.16/6.65 cm E/N/U positioning accuracy are achieved in the simulated kinematic mode. During a 28-min stepper motor driven movement test, 3.48/14.88 cm 2D/3D kinematic positioning accuracy is obtained using the BDS-3 PPP service.

Energization of Charged Test Particles in Magnetohydrodynamic Fields: Waves versus Turbulence Picture

Direct numerical simulations of three-dimensional compressible magnetohydrodynamic (MHD) turbulence have been performed in order to study the relation between wave modes and coherent structures and the consequent energization of test particles. Moreover, the question of which is the main mechanism of this particle energization is rigorously discussed. In particular, using the same initial conditions, we analyzed the nonlinear and linear evolution of a turbulent state along with the case of randomized phases. Then, the behaviors of the linear and nonlinear simulations were compared through the study of the time evolution of particle kinetic energy and preferential concentration. Also, spatiotemporal spectra were used to identify the presence of wave modes and quantify the fraction of energy around the MHD modes in linear and nonlinear simulations. Finally, the variation of the correlation time of the external forcing is studied in detail along with the effect on the particle energization (and clustering) and the presence of wave modes. More specifically, particle energization tends to decrease when the fraction of linear energy increases, supporting the idea that energization by structures is the dominant mechanism for particle energization instead of resonance with wave modes as suggested by Fermi energization theory.

Minimal Mechanisms Responsible for the Dispersive Behavior of the Madden–Julian Oscillation

An attempt has been made to explore the relative contributions of moisture feedback processes on tropical intraseasonal oscillation or Madden–Julian Oscillation (MJO). We focused on moisture feedback processes, including evaporation wind feedback (EWF) and moisture convergence feedback (MCF), which integrate the mechanisms of convective interactions into the tropical atmosphere. The dynamical framework considered here is a moisture-coupled, single-layer linear shallow-water model on an equatorial beta-plane with zonal momentum damping. With this approach, we aimed to recognize the minimal physical mechanisms responsible for the existence of the essential dispersive characteristics of the MJO, including its eastward propagation (k>0), the planetary-scale (small zonal wavenumbers) instability, and the slow phase speed of about ≈5 m/s. Furthermore, we extended our study to determine each feedback mechanism’s influence on the simulated eastward dispersive mode. Our model emphasized that the MJO-like eastward mode is a possible outcome of the combined effect of moisture feedback processes without requiring additional complex mechanisms such as cloud radiative feedback and boundary layer dynamics. The results substantiate the importance of EWF as a primary energy source for developing an eastward moisture mode with a planter-scale instability. The eastward moisture mode exhibits the highest growth rate at the largest wavelengths and is also sensitive to the strength of the EWF, showing a significant increase in the growth rate with the increasing strength of the EWF; however, the eastward moisture mode remains unstable at planetary-scale wavelengths. Moreover, our model endorses that the MCF alone could not produce instability without surface fluxes, although it has a significant role in developing deep convection. It was found that the MCF exhibits a damping mechanism by regulating the frequency and growth rate of the eastward moisture mode at shorter wavelengths.

The Emergence of the Contractor’s Innovation Capability at Project Level: An Agent-Based Modeling Approach

Contractors play a crucial role in ensuring efficient innovation within construction projects but limited research has focused on the innovation capability of contractors. This study utilizes a multi-method approach, including case studies, surveys, and interviews to collect data for analysis. Based on this, a conceptual model is proposed and a simulation mode which utilizes agent-based modeling (ABM) is constructed. ABM is the microscopic bottom-up approach which can describe and follow the agents and interactions. This study proposes a novel conceptual model to examine the emergence of contractor innovation capability at the project level, from a knowledge flow perspective. It fills the research gap regarding innovation capability in temporary cross-organizational projects. Additionally, an ABM simulation model is developed considering project and participant characteristics, providing insights into the formation rule and development mechanisms of contractors’ innovation capability at the project level. The conclusions are as follows: (1) The demand for innovation drives the innovative behavior of different entities within the project. (2) Knowledge availability in public domains and other entities’ knowledge creation capability provide critical support for contractor innovation. (3) Contractors’ capability to absorb and integrate knowledge serves as the foundation for achieving innovation. (4) When contractors possess strong capabilities, effective synergy among organizations facilitates the generation of innovative outcomes.

Dynamic model-assisted transferable network for liquid rocket engine fault diagnosis using limited fault samples

The accurate detection and diagnosis of faults in Liquid Rocket Engines (LREs) are critical for ensuring space mission safety. However, the limited availability of actual fault samples and the diversification of potential faults present significant challenges in achieving precise diagnosis. To overcome these obstacles, we propose a dynamic model-assisted transfer learning approach. In this study, we first modularize the LRE and establish a dynamic model based on the mathematical principles of each module. Subsequently, we artificially established a fault module model, injected faults into the normal model, and simulated various fault modes to expand the fault sample library. Leveraging this augmented dataset in combination with a limited number of actual fault samples, we employ transfer learning to fine-tune a Convolutional Neural Network (CNN). Compared with other classic methods, the migrated CNN effectively adapts to the distribution of real data and significantly improves the accuracy of LRE fault diagnosis.

Winds versus jets: a comparison between black hole feedback modes in simulations of idealized galaxy groups and clusters

ABSTRACT Using the SWIFT simulation code, we compare the effects of different forms of active galactic nuclei (AGNs) feedback in idealized galaxy groups and clusters. We first present a physically motivated model of black hole (BH) spin evolution and a numerical implementation of thermal isotropic feedback (representing the effects of energy-driven winds) and collimated kinetic jets that they launch at different accretion rates. We find that kinetic jet feedback is more efficient at quenching star formation in the brightest cluster galaxies (BCGs) than thermal isotropic feedback, while simultaneously yielding cooler cores in the intracluster medium (ICM). A hybrid model with both types of AGN feedback yields moderate star formation rates, while having the coolest cores. We then consider a simplified implementation of AGN feedback by fixing the feedback efficiencies and the jet direction, finding that the same general conclusions hold. We vary the feedback energetics (the kick velocity and the heating temperature), the fixed efficiencies and the type of energy (kinetic versus thermal) in both the isotropic and the jet case. The isotropic case is largely insensitive to these variations. On the other hand, jet feedback must be kinetic in order to be efficient at quenching. We also find that it is much more sensitive to the choice of energy per feedback event (the jet velocity), as well as the efficiency. The former indicates that jet velocities need to be carefully chosen in cosmological simulations, while the latter motivates the use of BH spin evolution models.

Macroscopic and microscopic mechanical characteristics and crack propagation behavior of sandstone-like samples with single cracks under freeze–thaw cycles: Experimental and numerical simulation

In permafrost regions, rock engineering projects inevitably suffer from the effects of freeze–thaw (F-T) cycles under complex geographical and climatic conditions. Under F-T cycles, the damage and deterioration of macro- and microdefects, such as joints and cracks, in the rock will reduce the structural stability of the rock and even lead to frost damage in rock engineering. In this study, through indoor F-T cycle tests, uniaxial/triaxial compression tests, acoustic emission monitoring, and discrete element method (PFC 3D) modeling, the macro/microscopic mechanical characteristics and crack propagation behavior of sandstone-like samples with single cracks under F-T cycles were investigated. The results show that the compressive strength of sandstone-like samples with single cracks tends to decrease and then increase with an increasing crack angle and exhibits a stable decreasing trend with increasing F-T cycles, indicating a significant crack angle effect and F-T deterioration effect. Additionally, the confining pressure has an inhibiting effect on the F-T deterioration of samples, and there is a mutual inhibition relationship between the F-T deterioration effect and the crack angle effect. The characteristics of the acoustic emission signals during the loading process of sandstone-like samples with single cracks show good consistency with the stress–strain curves. The analysis of fracture mechanisms based on rise time/amplitude (RA) and average frequency (AF) is consistent with the macroscopic failure modes observed in the experiments. Moreover, with an increase in the number of F-T cycles, the number of tension cracks in the sandstone-like samples with single cracks increases, while the number of shear cracks decreases. The crack propagation behavior of sandstone-like samples with single cracks obtained through discrete element simulations (PFC 3D) is mainly divided into four stages: Stage I - initial calm stage, Stage II - crack initiation stage, Stage III - crack propagation stage, and Stage IV - failure stage. The simulated mechanical properties and failure modes agree well with the experimental results, and five crack propagation modes of sandstone-like samples with single cracks under F-T cycles were proposed: direct tension (DT), relative tension (RT), shear-tension (ST), direct shear (DS) and relative shear (RS).

Seismic behaviors of CFT-column frame-four-corner bolted connected buckling-restrained steel plate shear walls using ALC/RAC panels

A Frame-Buckling Restrained Steel Plate Shear Walls (BRSPSWs) system has been designed, featuring a steel plate connected to frame elements, to withstand lateral loads like seismic or wind forces. This system incorporates recycled aggregate concrete (RAC) to create concrete-filled and concrete panels, promoting eco-friendly and sustainable construction materials. Two single-span, two-floor specimens were tested under cyclic quasi-static load. A four-corner bolted connection was used to connect the steel plate to the square concrete-filled steel tubes (CFTs) column and H-section beam, minimizing the potential deformation of the frame elements produced by the tension field of the steel plate after high-order bucking. The steel plate was sandwiched using either autoclaved lightweight concrete (ALC) or RAC panels. The study analyzed failure modes, load-displacement responses, and characteristic capacities. Test results inferred that BRSPSWs exhibited favorable cyclic behavior, with similar failure modes observed using both ALC and RAC panels. The buckling of steel plates was reduced, and the type of restrained panels had a negligible impact on buckling. Consequently, ALC panels can effectively replace RAC panels. Furthermore, bearing capacities and yield stiffness were primarily determined by the bolted connection forms. A finite element (FE) modeling was developed using ABAQUS software and validated against test results. This FE modeling method successfully simulated failure modes and load-displacement curves. Parametric analyses were conducted and revealed that bearing capacity and yield stiffness positively correlated with steel plate thickness, bolt diameter, and the number of bolts but negatively correlated with the axial compression ratio. In contrast, the panel thickness and span length had a minor impact due to shear deformation in the bolted connection. Based on the test results and parametric studies, an equation for the yield-bearing capacity of BRSPSWs was proposed and verified.

Axial quasi-static crushing of composite tubes: An investigation on the influence of the modeling techniques

Carbon fiber-reinforced plastic (CFRP) composites perform remarkably as crashworthy structures in transport vehicles. They promise to improve the crashworthiness of vehicles in addition to weight savings thanks to their superior strength-to-weight ratio. However, designing composite crashworthy structures is challenging since predicting the energy absorption values and crushing behavior are not straightforward. Finite element modeling is a very effective numerical technique to predict energy absorption values and shorten the design process of composite structures, yet it is also quite hard to simulate the crushing of composite structures due to their complex damage mechanisms. This paper presents an investigation of the axial crushing behavior of composite tubes made of woven fabric CFRP and the influence of the different modeling techniques. Macro-scale stacked shell modeling approach is adopted to model the composite tubes. Various virtual debris wedge models are incorporated to obtain realistic failure modes in simulations. Simulated crushing morphologies and energy absorption values are compared with the experimental test results. Furthermore, the prediction capability of the models and the influence of mesh geometry used for rigid flat platen crushers are examined. It is found that the geometry of the virtual debris wedge and mesh geometry of the flat platen crusher affect the simulated crushing modes and level of the absorbed energy predicted.

High‐Resolution Large‐Eddy Simulations of Flow in the Complex Terrain of the Canadian Rockies

AbstractImproving the calculation of land‐atmosphere fluxes of heat and water vapor in mountain terrain requires better resolution of thermally driven diurnal winds (i.e., valley, slope winds) due to differential heating by terrain and radiative fluxes. In this study, the Weather Research and Forecasting model is used to simulate flow in large‐eddy simulation (LES) mode over the complex terrain of the Fortress Mountain and Marmot Creek research basins, Kananaskis Valley, Canadian Rockies, Alberta in mid‐summer. The model was used to examine the temporal and spatial evolution of local winds and near‐surface boundary layer processes with variability in topography and elevation. Numerically resolving complex terrain wind flow effects require smaller grid cell size. However, the use of terrain‐following coordinates in most numerical weather prediction models results in large numerical errors when flow over steep terrain is simulated. These errors propagate through the domain and can result in numerical instability. To avoid this issue when simulating flow over steep terrain a local smoothing approach was used, where smoothing is applied only where slope exceeds some predetermined threshold. LES results from local smoothing were compared with a mesoscale model and LES with global smoothing. Simulations are evaluated using sounding data and meteorological stations. The differences in flow patterns and reversals in two mountain basins suggest that valley geometry and volume is relevant to the break up of inversion layers, removal of cold‐air pools, and strength of thermally driven winds.

Thermal analysis of phase change materials storage in solar concenter

Thermal analysis of high-temperature phase change materials (PCM) is conducted with the consideration of a 20% void and buoyancy-driven convection in a stainless-steel capsule. The effects of the thermal expansion and the volume expansion due to phase change on the energy storage and retrieval process are explored. The used water to fill the void between two different wax paraffin and stearic acid spheres is considered as a potential PCM for concentrated solar power. The charging/discharging process into and from the capsule wall is simulated under different boundary conditions for laminar and turbulent flows. Computational models are conducted by applying an enthalpy-porosity method and volume of fluid method to calculate the transport phenomena within the PCM capsule, including an internal air void. A simplified two-dimensional model of the PCM contained within the spheres is constructed and thermal analyses are performed for the transition from solid to liquid states. Simulated charging process modes are compared with the theory. According to experiments, the temperature distributions from 40-60 mm without and with 60 mm with copper fin have different behavior. The paraffin takes less time than stearic acid for total transformation at a rate of 0.5. The size of the sphere increases over the amount of time and the phase of the sphere to complete changes as stearic acid expands more than paraffin during the transition. Inserting a rectangular fin, that is made from copper into the ball reduces the cycle time and increases output.