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The 100-m X-ray Test Facility of the Institute of High Energy Physics (IHEP) was initially proposed in 2012 for the test and calibration of the X-ray detectors of the Hard X-ray Modulation Telescope (HXMT) with the capability to support future X-ray missions. The large instrument chamber connected with a long vacuum tube can accommodate the X-ray mirror, focal plane detector and other instruments. The X-ray sources are installed at the other end of the vacuum tube with a distance of 105 m, which can provide an almost parallel X-ray beam covering 0.2 ∼ 60 keV energy band. The X-ray mirror modules of the Einstein Probe (EP) and the enhanced X-ray Timing and Polarimetry mission (eXTP) and payload of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) have been tested and calibrated with this facility. It has been also used to characterize the focal plane camera and aluminum filter used on the Einstein Probe. In this paper, we will introduce the overall configuration and capability of the facility, and give a brief introduction of some calibration results performed with this facility.

An appointed-time prescribed performance control with continuously changeable boundary and artificial intelligence is proposed to achieve the simulation robust control in the altitude ground test facility involving engine rapid throttle movement. Firstly, considering the effects of actuator delays and parameter uncertainties, the backstepping method is employed to improve the control performance. Next, the long short-term memory neural network is used to realize a more precise feedforward control, enhancing the altitude ground test facility's response speed and disturbance rejection capability. Then, a continuously differentiable prescribed performance function with changeable boundaries is designed for the disturbance rejection control during the engine's rapid throttle movement of the altitude ground test facility. The proposed method effectively solves the problem of the possible collapse of general appointed-time prescribed performance control subjected to severe interference or performance degradation caused by expanding the boundary for security. Additionally, the control performance is further improved under the pre-extended boundary change strategy and parameter adaptive adjustment. Finally, experiments without complicated instructions and changes in the engine intake are conducted to validate the application potential of the proposed method in the multi-task continuous simulation with different performance requirements.

Reflectivity is a key topic in soft X-ray optics research and serves as the foundation for studying the performance of the optics for X-ray astronomical satellites. Since its establishment, the 100-m X-ray Test Facility (100XF) has been continuously developing various testing functionalities, including calibration of timing, imaging, and energy response. This paper provides a detailed description of the X-ray optics reflectivity test method based on the 100XF, which can be applied to various grazing incident X-ray optics, including Wolter-I and lobster-eye types, significantly expanding the application scope of the 100XF. A flat mirror sample (SiO 2 coated on a Si wafer) is tested. Results of the variation of reflectivity with angle @ C-K α (0.28 keV), Al-K α (1.49 keV), and Ti-K α (4.50 keV) are presented in the description. The reflectivity test method has also been applied to the coating reflectivity study of the enhanced X-ray Timing and Polarimetry Mission (eXTP) mirror. At the same time, a new method utilizing the continuum spectrum of bremsstrahlung was carried out to study the continuous variation of reflectivity with energy, greatly improving efficiency compared to traditional methods, and all the results show a good agreement with the theoretical values. The deviation between the test and theoretical values in the low-energy range (1.5-8.0 keV) is less than 10%.

The simulated altitude test facility, as an important means to verify the performance, characteristics, and evaluation result criteria of aero-engines, has a pivotal engineering significance in the process of aero-engine development and promotion of application. In order to cope with the drawbacks of traditional techniques for experimental processes, this paper proposes the real-time data extraction and transfer techniques with multiple optimization strategies and the fault diagnosis technology of simulated altitude test facility with an improved optimization algorithm is propose, Firstly, the optimization strategy based on peak shaving + peak fast processing and token bucket instructions with multi-threaded parallel processing flow allocation call logic is used to realize the test data for fast extraction and migration demand, and then the overall data transfer function is optimized in granularity improvement schemes by using the abstraction optimization strategy mechanism based on Direct Routing mode to maximise real-time targets while ensuring correspondence and completeness of test data. Finally, the random forest algorithm with Multi-Head Attention optimization is used to implement the diagnostic technology research of the simulated altitude test facility under two scenarios under the data-driven mode, and the analytical comparison and validation results with the unimproved and optimized Random Forest algorithm are given. The results indicate that the amount of test data synchronization reaches 300 + lines per second, the accuracy of fault diagnosis identification is increased by 30% at the highest degree, and the proposed improvement research has a very high degree of application value and innovativeness.

A high altitude test facility was developed for the experimental studies on nozzles for various levels of vacuum. The current study is focused on the performance of the nozzle under various altitude condition and to characterized the high altitude test facility. A supersonic nozzle designed for Mach 2.5 is used for the study. Compressed air is taped from the high pressure plenum having a pressure of 20 bar and is regulated and expanded through the nozzle. The inlet pressures for the study is varied from 4.5 to 10 bar. The nozzle is within the enclosure which is evacuated to 0.7–0.02 bar. Schlieren is used to view the flow condition at the end of the nozzle. A nozzle for 2.5 Mach is designed and tested in HAT facility. The nozzle design is validated with the CFD for various NPR. The high altitude test facility is characterized for various NPR and is found to be optimum flow at 14 NPR for 33 s at an inlet pressure of 4.5.

The accurate execution of aeroengine flight environment simulation tests relies on the electro-hydraulic servo valve control system in the altitude test facility. However, time delays arising from various factors, such as friction or sensor latency, impose significant constraints on system responsiveness and control precision. To address this challenge, an enhanced active disturbance rejection control has been developed. The proposed method employs an improved output prediction constructed by tracking differentiator to mitigate delay effects, introduces the Taylor compensator to more accurately capture future signal trends, and incorporates a dynamic adjustment mechanism based on error variation to optimize the parameters of the extended state observer in real time, thereby enhancing robustness under varying operating conditions. The simulation results demonstrate that under fixed-delay conditions, the proposed algorithm exhibits fast response characteristics; under varying-delay conditions, unlike model-dependent approaches, it remains less affected by delay fluctuations and maintains superior response speed and stability, thereby ensuring the accuracy of flight environment simulation tests.

This paper presents an evaluation method for the interruption capability of direct-current (DC) circuit breakers. We induced various hybrid types of DC circuit breakers (DCCBs) and proposed a suitable DC interruption test method to simulate the scenario of a short circuit occurring in a DC system during normal operation. To analytically estimate the interruption capability of the DCCB, we calculated the magnitude of the DC interruption current, rate of change of current (di/dt), and maximum transient recovery voltage (TIV) using an equivalent circuit model. To experimentally evaluate the interruption capability of the DCCB, we constructed a practical DC interruption test facility based on an equivalent circuit. The measured DC interruption test current was compared with the values calculated using the equivalent circuit model.

Altitude test facilities for aero-engines employ multi-chamber, multi-valve intake systems that require effective decoupling and strong disturbance rejection during transient tests. This paper proposes a coordinated active disturbance rejection control (ADRC) scheme based on external penalty functions. The chamber pressure safety limit is formulated as an inequality-constrained optimization problem, and an exponential penalty together with a gradient based algorithm is designed for dynamic constraint relaxation, with guaranteed global convergence. A coordination term is then integrated into a distributed ADRC framework to yield a multi-valve coordinated ADRC controller, whose asymptotic stability is established via Lyapunov theory. Hardware-in-the-loop simulations using MATLAB/Simulink and a PLC demonstrate that, under ±3 kPa pressure constraints, the maximum engine inlet pressure error is 1.782 kPa (77.1% lower than PID control), and under an 80 kg/s2 flow-rate disturbance, valve oscillations decrease from ±27% to ±5%. These results confirm the superior disturbance rejection and decoupling performance of the proposed method.

To solve the modeling problem of altitude ground test facility (AGTF) exhaust systems, which is caused by nonlinearity along the gas path and the difficulty of ejection factor calculation, a multi-cavity iterative modeling method is presented. The components of exhaust systems, such as the exhaust diffuser and cooler, are built with a series of volumes. It overcomes the disadvantage that traditional lumped-parameter models have, whereby they cannot calculate the dynamic parameters along the gas path. The exhaust system model is built with an iterative method based on multi-cavity components, and simulations are carried out under experimental conditions. The simulation results show that the maximum error of pressure is 2 kPa in the steady state and less than 6 kPa in the transient process compared with experimental data. Closed-loop simulations are also carried out to further verify the accuracy and effectiveness of the multi-cavity iterative exhaust system modeling method.

Purpose The purpose of this paper is to demonstrate the aerodynamic behavior of a supersonic combustion test bench (SCTB) components, as the transition piece and the combustor of a scramjet (supersonic combustion ramjet), manufactured by 3D printing or additive manufacturing (AM). Design/methodology/approach For the dimensional and structural analysis of the manufactured models, a portable 3D scanner was used to generate the mesh of its dimensions, and to compare them before and after the experiments, a roughness measuring system was also used to verify the roughness inside the models before and after the tests, as roughness is an important parameter because it directly affects the boundary layer. For the visualization of the flow, the non-intrusive schlieren optical technique was used. Findings The experiments were carried out on the SCBT for Mach 2 flows, using the manufactured prototypes and showed that there was no structural and dimensional change of the model after the test batteries. It was found that the roughness presented by the material did not affect the quality of the flow generated. This shows that the investigated material can also be applied in experiments with supersonic flow. Originality/value This paper presents that it is possible to use in ground test facilities, for the studies of supersonic flow (in cold condition), pieces and models manufactured by 3D printing without affecting the quality of the flow generated during the experiments. This study presents a new perspective to approach AM applied in the studies of supersonic flows.