Numerical simulation and experimental validation of multiphysics field coupling mechanisms for a high power ICP wind tunnel

We take the established inductively coupled plasma(ICP) wind tunnel as a research object to investigate the thermal protection system of re-entry vehicles. A 1.2-MW high power ICP wind tunnel is studied through numerical simulation and experimental validation. The distribution characteristics and interaction mechanism of the flow field and electromagnetic field of the ICP wind tunnel are investigated using the multi-field coupling method of flow, electromagnetic, chemical, and thermodynamic field. The accuracy of the numerical simulation is validated by comparing the experimental results with the simulation results. Thereafter, the wind tunnel pressure, air velocity, electron density, Joule heating rate, Lorentz force, and electric field intensity obtained using the simulation are analyzed and discussed. The results indicate that for the 1.2-MW ICP wind tunnel, the maximum values of temperature, pressure, electron number density, and other parameters are observed during coil heating. The influence of the radial Lorentz force on the momentum transfer is stronger than that of the axial Lorentz force. The electron number density at the central axis and the amplitude and position of the Joule heating rate are affected by the radial Lorentz force. Moreover, the plasma in the wind tunnel is constantly in the subsonic flow state, and a strong eddy flow is easily generated at the inlet of the wind tunnel.

Simulation and experiment of a photovoltaic—air source heat pump system with thermal energy storage for heating and domestic hot water supply

For China,the development of low-energy buildings is one of the necessary routes for achieving carbon neutrality.Combining photovoltaic(PV)with air source heat pump(ASHP)yields a great potential in providing heating and domestic hot water(DHW)supply in non-central heating areas.However,the diurnal and seasonal inconsistencies between solar availability and building heat load can severely affect the efficacy of solar energy systems.This study creates and numerically simulates a PV-ASHP system with thermal energy storage(TES)in transient system simulation software,TRNSYS.Experimental studies are conducted to validate the simulation model.The system’s yearly operational characteristics are simulated to reveal the energy conversion relationship between the system’s thermoelectric storage and heating and DHW demand.The results show that the synergy between heating and DHW simultaneously improves the direct utilization of solar energy compared to single heating.The yearly self-consumption and self-satisfaction rates of PV and the COP of the ASHP increase by 131.25%,10.53%and 9.56%,respectively.Solar energy contributes 55.54%to the system,with a PV capacity of 82 W per square meter of building area.This study provides fresh approaches to developing flexible building-integrated PV-ASHP technologies and balance of the energy exchange among the PV,building load and TES.

Analysis and experimental study on resistance-increasing behavior of composite high efficiency autonomous inflow control device

Bottom water coning is the main reason to reduce the recovery of horizontal bottom water reservoir. By water coning, we mean the oil-water interface changes from a horizontal state to a mound-shaped cone and breaks through to the wellbore. Autonomous inflow control device(AICD) is an important instrument maintain normal production after bottom water coning, however, the resistance increasing ability of the swirl type AICD is insufficient at present, which seriously affects the water control effect. Aiming this problem, this paper designs a multi-stage resistance-increasing and composite type AICD. The separation mechanism of oil-water two phases in this structure, the resistance form of oil-water single phase and the resistance-increasing principle of water phase are analyzed. Establishing the dual-phase multi-stage separation and resistance-increasing model, and verified by measuring the throttling pressure drop and oil-water volume fraction of the AICD, it is found that the composite type AICD has the effect of ICD and AICD at the same time, which can balance the production rate of each well section at the initial stage of production, delay the occurrence of bottom water coning. In the middle and later stages of production, water-blocking can be effectively increased to achieve water control and stable production.After structural sensitivity analysis, the influence law of various structural parameters on the water control performance of composite AICD was obtained. The simulation calculation results show that,compared with the existing swirl type AICD, composite AICD has higher sensitivity to moisture content,the water phase throttling pressure drop is increased by 4.5 times on average. The composite AICD is suitable for the entire stage of horizontal well production.

Underconstrained Cable-Driven Parallel Suspension System of Virtual Flight Test Model in Wind Tunnel

An underconstrained cable-driven parallel robot(CDPR)suspension system was designed for a virtual flight testing(VFT)model.This mechanism includes two identical upper and lower kinematic chains,each of which comprises a cylindrical pair,rotating pair,and cable parallelogram.The model is pulled via two cables at the top and bottom and fixed by a yaw turntable,which can realize free coupling and decoupling with three rotational degrees of freedom of the model.First,the underconstrained CDPR suspension system of the VFT model was designed according to the mechanics theory,the degrees of freedom were verified,and the support platform was optimized to realize the coincidence between the model’s center of mass and the rotation center of the mechanism during the motion to ensure the stability of the support system.Finally,kinematic and dynamical modeling of the underconstrained CDPR suspension system was conducted;the system stiffness and stability criteria were deduced.Thus,the modeling of an underconstrained,reconfigurable,passively driven CDPR was understood comprehensively.Furthermore,dynamic simulations and experiments were used to verify that the proposed system meets the support requirements of the wind tunnel-based VFT model.This study serves as the foundation for subsequent wind tunnel test research on identifying the aerodynamic parameters of aircraft models,and also provides new avenues for the development of novel support methods for thewind tunnel testmodel.