Large-scale Physical Experiments Research Articles

Predicting the penetration depth and towing resistance of beam trawl fishing gears in sand

Accurate characterization of mechanical perturbations on the seabed is essential for developing models assessing the environmental impacts from physical disturbances. Furthermore, understanding the relationship between (1) seabed resistance and (2) penetration depth, can also facilitate the development of more efficient and less impactful fishing gears. This study examines these two aspects of tickler chain rigged beam trawling via large-scale physical experiments. Three scaled down models (“light,” “medium,” and “heavy” designs) were developed to represent the impacts from typical beam trawl configurations used in the North Sea and were towed at various speeds on a saturated sand bed. Results reveal that increasing the towing speed reduces the mean penetration depth and the steady-state towing resistance of the gears. Smaller scale physical model tests incorporating tickler chains in sand, demonstrate that the towing resistance is significantly influenced by the soil compaction and particle sizes. Moreover, our study offers a simple and efficient method to estimate the penetration depth and towing resistance of prototype beam trawl gears in sand. This approach, along with the associated research, may be valuable for marine scientists assessing trawling impacts and demersal fishing gear designers seeking to optimize efficiency while minimizing seabed disturbance.

Large-Scale Levee Breach Experiments With Foreshores

Coastal flood risk is expected to increase substantially in the near future. Main drivers are climate induced sea level rise, increased storm surge and land subsidence. Meanwhile, land subsidence compounds to increased extreme water levels as more land is susceptible to flooding. Without coastal defense or adaptation 50% more people are exposed to flooding than present day (Kireczi et al., 2020). Coastal regions are currently primarily protected by hard (grey) flood defenses such as storm surge barriers, seawall, dikes and dunes. Periodically, strengthening of these grey structures is necessary to comply with current or updated safety standards. For dikes, conventional strengthening methods are crest heightening or (base) widening. However, these methods have structural and financial limits. Instead, more sustainable methods are explored in which nature also plays a larger role. These solutions are known as Nature based Solutions (NbS). For flood protection, tidal marshes have gained great interest as a Nature based Solution in the past two decades. Tidal marshes provide a lot of ecosystem services (Barbier et al., 2011). One such service is flood protection, attributed to wave attenuation (Vuik et al, 2016). A secondary effect is flood impact reduction (Zhu et al., 2020) due to the high elevation of tidal marshes limiting the inflow to the breach. Secondly, the tidal marsh can act as a sill in front of the breach when water levels drop below the tidal marsh level. To quantify the effect of tidal marshes on flood impact the breaching process in combination with a tidal marsh (or foreshore in general) needs to be understood. In this study we performed a large-scale physical dike experiment where we breached a dike seven times. Three tests are done without a sediment layer in front of the dike (no foreshore), two with a sandy layer (sandy beach) and two with a clay layer (tidal marsh without vegetation). From the experiments we gain insight into differences in the dike breaching process with and without an erodible sediment layer in front of the dike

Calculating the number of radial cracks around a wellbore formed by liquid CO2 phase transition blasting (LCPTB) technology

Integrating liquid CO2 phase transition blasting (LCPTB) technology with hydraulic fracturing (HF) methods can help reduce wellbore damage, create multiple radial fractures, and establish a complex fracture network. This approach significantly increases the recovery efficiency of low-permeability oil and gas fields. Accurately calculating the number of fractures caused by LCPTB is crucial to predicting production enhancement effects and optimizing subsequent HF designs. However, few studies have conducted large-scale physical model experiments and proposed a method for calculating the fracture number. This study analyzed the initiation and propagation mechanism of cracks under the LCPTB, derived a calculation formula for crack propagation radius under stress waves, and then proposed a new, fast, and accurate method for calculating the fracture number using the principle of mass conservation. Through ten rock-breaking tests using LCPTB, the study confirmed the effectiveness of the proposed calculation approach and elucidated the variation rule of explosion pressure, the rock-breaking mechanism, and the impact of varying parameters on fracture number. The results show the accuracy and efficiency of the new calculation method, which is particularly suitable for fracturing technologies with high pressure rise rates. Recommendations include enlarging the diameter of the fracturing tube and increasing the liquid CO2 mass in the tube to enhance fracture effectiveness. Moreover, the method can be applied to other fracturing technologies, such as explosive fracturing (EF) within HF formations, indicating its broader applicability and potential impact on optimizing unconventional resource extraction technologies.

Spatial and Temporal Distribution Characteristics of Landslide Surge Based on Large-Scale Physical Modeling Experiment

Surge is a common secondary disaster caused by reservoir landslides. The study of its spatial and temporal distribution characteristics is important since it affects not only the normal operation of reservoirs but also the safety of people residing along the river. This paper presents a large-scale three-dimensional physical modeling experiment using a near-dam high-position landslide project as a prototype. It investigated the relationships between the river course characteristics, the landslide volume, the head wave velocity of the landslide surge, the waveform of surges, and the head wave crest of the wave along the course in depth. The results indicate that the head wave velocity of the landslide surge is basically unchanged during the propagation process, and it is minimally affected by the landslide volume. The waveform distribution characteristics and head wave crests change considerably in the diversion area and the curved areas but remain mostly unchanged in the topographic similarity area. In addition, there is a negative correlation between the head wave crest and the cross-sectional area of the river course. Furthermore, under conditions of a large landslide volume, the influence of the cross-sectional area of the river channel on the wave height of landslide surges becomes more significant. Finally, the maximum wave height along the course may not necessarily occur in the head wave crest; it could occur in the second wave or even the subsequent ones.

Design of a high-precision clock distribution and synchronization system

In large-scale nuclear and particle physics experiments, there is a high demand for high precision clock distribution and synchronization. In this paper, the design and testing of a high precision clock distribution and synchronization system for the CSR External Target Experiment (CEE) is presented. To achieve high synchronization precision, a dedicated high-quality clock distribution network is designed, while the timestamp synchronization is achieved over the existing trigger link in CEE with a customized protocol in order to simplify the system structure. Automatic metastability elimination and real-time monitoring of both the timestamps on the front end nodes and the clock electronics status are also implemented. The test results indicate that the period jitter of the clock network is better than 4 ps rms, and all the expected functionalities have been achieved successfully.

Research on Water Invasion Law and Control Measures for Ultradeep, Fractured, and Low-Porosity Sandstone Gas Reservoirs: A Case Study of Kelasu Gas Reservoirs in Tarim Basin

The exploitation of ultradeep, fractured, and low-porosity gas reservoirs often encounters challenges from water invasion, exacerbated by the presence of faults and fractures. This is particularly evident in the Kelasu gas reservoir group, located in the Kuqa Depression of the Tarim Basin. The complexity of the water invasion patterns in these reservoirs demands a thorough investigation to devise effective water control measures. To elucidate the water invasion patterns, a combined approach of large-scale physical modeling and discrete fracture numerical simulations was adopted. These models allowed for the identification and categorization of water invasion behaviors in various gas reservoirs. Furthermore, production dynamic analysis was utilized to tailor water control strategies to specific invasion patterns. The large-scale physical simulation experiment revealed that water invasion in gas reservoirs is primarily influenced by high-permeability channels (faults + fractures), and that the gas production rate serves as the key factor governing gas reservoir development. The range of gas extraction rates spans from 3% to 5%. As the gas extraction rate increases, the extraction intensity diminishes and the stable production duration shortens. On the basis of the changes in the water breakthrough time and water production rate, a 2% gas extraction rate is determined as the optimal rate for the model. The embedded discrete fracture numerical simulation model further supports the findings of the physical simulation experiments and demonstrates that ① this type of gas reservoir exhibits typical nonuniform water invasion patterns, controlled by structural location, faults, and degree of crack development; ② the water invasion patterns of gas reservoirs can be categorized into three types, these being explosive water flooding and channeling along faults, uniform intrusion along fractures, and combined intrusion along faults and fractures; ③ drawing from the characteristics of water invasion in various gas reservoirs, combined with production well dynamics and structural location, a five-character water control strategy of “prevention, control, drainage, adjustment, and plugging” is formulated, with the implementation of differentiated, one-well, one-policy governance. The study concludes that a proactive approach, prioritizing prevention, is crucial for managing water-free gas reservoirs. For water-bearing reservoirs, a combination of three-dimensional water plugging and drainage strategies is recommended. These insights have significant implications for extending the productive lifespan of gas reservoirs, enhancing recovery rates, and contributing to the economic and efficient development of ultradeep, fractured, and low-porosity gas reservoirs.

Damaging effects of earth fissures on high-speed railway bridges: Insights from physical experiments and numerical simulations

Earth fissure is a typical geological phenomenon related to surface rupture. With the rapid development of high-speed railways (HSRs) in recent years, earth fissure disasters pose a serious challenge to the construction and subsequent safe operation of HSRs. Here, we aimed to investigate the damaging effect of earth fissure activities on HSR bridges spanning the earth fissure zone. Taking the Shuixiu earth fissure of Da-Xi HSR as the prototype, a large-scale laboratory physical experiment with geometric model scale 1:20 was carried out to reveal the deformation and failure characteristics of HSR bridges under earth fissure activity. In addition, the damage influence range and damage mode of HSR bridges crossing earth fissures are further determined by numerical simulation. The results show that the earth fissure activity mainly has damaging effects on the structure of HSR bridges near the earth fissure zone, which is mainly manifested as uneven settlement of reinforced concrete pile, bending deformation of box girder and cracking of track slab. The width of the influence zone of Shuixiu earth fissure on the HSR bridge is determined to be 32.4 m. Moreover, the pile-end pressure on the hanging wall side of the earth fissure gradually decreases with the earth fissure activity, while that on the footwall side increases significantly. Most importantly, it is emphasized that a practical long-term monitoring and early warning system of HSR bridge structures should be established to prevent the hazards caused by earth fissure activities. The above understanding will benefit to the design, construction and operation of Da-Xi HSR line, and also provide significant guidance and reference to the construction of HSR bridges in other earth fissure prone areas.

XkitS：A computational storage framework for high energy physics based on EOS storage system

Large-scale high-energy physics experiments generate scientific data at the scale of petabytes or even exabytes, requiring high-performance data IO for processing. However, in large computing centers, computing and storage devices are typically separated. Large-scale data transfer has become a bottleneck for some data-intensive computing tasks, such as data encoding and decoding, compression, sorting, etc. The time spent on data transfer can account for 50% of the entire computing task. The larger the amount of data accessed, the more significant this cost becomes. One attractive solution to address this problem is to offload a portion of data processing to the storage layer. However, modifying traditional storage systems to support computation offloading is often cumbersome and requires a broad understanding of their internal principles. Therefore, we have designed a flexible software framework called XkitS, which builds a computable storage system by extending the existing storage system EOS. This framework is deployed on the EOS FTS storage server and offloads computational tasks by invoking the computing capabilities (CPU, FPGA, etc.) on FTS. Currently, it has been tested and applied in the data processing of the Large High Altitude Air Shower Observatory (LHAASO), and the results show that the time spent on data decoding using the computable storage technology is half of that using the original method.

Porting LHAASO WFCTA simulation job to ARM computing cluster

With the advancement of many large-scale high-energy physics experiments, the amount of data to be processed and analyzed has significantly increased. For example, since the start of the Large High Altitude Air Shower Observatory (LHAASO) experiment in 2020, their simulation jobs have been running on an Intel X86 cluster, producing only a fraction of the planned data for the first phase due to limited CPU resources. Therefore, it is necessary to explore and expand other computing service devices. We built an application ecosystem based on the ARM architecture to support offline data processing for high-energy physics. The main work includes porting the offline software based on LHAASO experiments to run on ARM machines, formulating data transfer and job scheduling strategies in the ARM cluster, and evaluating performance and power consumption in both Intel X86 and ARM clusters. The results show that the LHAASO simulation jobs can run correctly on the ARM computing cluster. The singlecore performance of Intel X86 CPUs is better than ARM CPUs, but for the entire server with a multicore architecture, ARM servers perform better.

Large Scale Experimental Study on Waves and Submerged Horizontal Cylinders

A large-scale physical model experiment was conducted to study the interaction between regular waves and submerged horizontal cylinders, breaking through the bottleneck of a low Reynolds number in a traditional small water tank. The surface pressure distribution and overall force of submerged horizontal cylinders at different submerged depths in waves with different heights and periods under a high Reynolds number were analyzed, and the variation in first- and second-order wave forces with wave height periods was analyzed. Subsequently, the influence of the cylinder on the wave field was analyzed, and the reflection coefficient was obtained through the three-point separation method. According to the analysis of the experimental results, the horizontal and vertical forces acting on the submerged cylinder per linear meter are similar, with the horizontal force slightly greater than the vertical force; at the same time, the submerged cylinder has a certain reflection effect on long-period waves. The summary, analysis, and display of relevant experimental results provide validation support for the current high-precision mathematical model as much as possible.

A generic node identification and routing algorithm in a distributed data acquisition platform: D-Matrix

Data acquisition (DAQ) systems are vital components in large-scale physics experiments. For communication, control and tracking purposes, all system components must be unambiguously identified. D-Matrix, as a generic distributed stream processing DAQ platform, accommodates various device connection methods, including networking, PCIe bus, point-to-point optical fiber links, etc. Although there are mature node identification solutions for each connection method individually, the uniform solution applicable to all connection methods remains crucial in a generic DAQ platform. D-Matrix abstracts a unified Multiple Point-to-Point transmission model (MPP model), supporting various physical connection methods and enabling multiple communication channels on a single physical link. Referring to the tree universal address system, a generic automatic node identification algorithm is proposed based on the MPP model. With simple configuration, this algorithm enables automatic node traversal, yielding a routing-based identification result that supports clustering and hierarchical node management requirements common in large-scale physics experiments. This paper explains the details of the algorithm and presents an example of the DAQ system based on the algorithm.

Large-scale physical experimental study on the evolution of 3D bedform by irregular waves

A large-scale physical experiment was conducted to analyze the morphological seabed evolution in a large-wave flume at the Tianjin Research Institute for Water and Transport Engineering. The morphologies of the bedforms, ranging from two to three dimensions, were analyzed as wave mobility (represented by ѱw) increased. The sand-ripple morphology underwent four stages: straight, staggered, lunate and flat. Furthermore, the three-dimensional (3D) features and flat patterns were enhanced with increasing ѱw. The seabed ripple was processed using a wavelet transform and filter method to eliminate the effects of noise and dunes. The ripple wavelength followed the gamma and lognormal distributions for irregular waves, whereas the distribution of ripple height transitioned from normal to exponential with increasing ѱw. Furthermore, to predict the ripple-geometry statistics more accurately, a modified predictor was developed based on the acquired large-scale experimental data. The findings of this study can aid the development of innovative methods for evaluating bedform morphologies and statistical parameters.

Research and deployment of a Python-based software framework for large-scale physical experiment control

This paper presents a python-based, open-source framework for slow control systems used in particle physics experiments. The framework includes several functions such as display, data query, alarm, log and remote monitoring, etc. The data communication utilizes the MQTT (Message Queuing Telemetry Transport) protocol, ensuring real-time and reliable data transmission. The object-oriented programming approach ensures each functional module's independence and reusability, making them easily interchangeable and extendable through configuration files in various applications. Finally, two case deployment applications of the framework are provided, where both of them are tested with Docker.

Life cycle analysis of the GRAND experiment

The goal of our study is to assess the environmental impact of the installation and use of the Giant Radio Array for Neutrino Detection (GRAND) prototype detection units, based on the life cycle assessment (LCA) methodology, and to propose recommendations that contribute to reduce the environmental impacts of the project at later stages. The functional unit, namely the quantified description of the studied system and of the performance requirements it fulfils, is to detect radio signals autonomously during 20 years, with 300 detection units deployed over 200km2 in the Gansu province in China (corresponding to the prototype GRANDProto300). We consider four main phases: the extraction of the materials and the production of the detection units (upstream phases), the use and the end-of-life phases (downstream phases), with transportation between each step. An inventory analysis is performed for the seven components of each detection unit, based on transparent assumptions. Most of the inventory data are taken from the Idemat2021 database (Industrial Design & Engineering Materials). Our results show that the components with the highest environmental impact are the antenna structure and the battery. The most pregnant indicators are ‘resource use’, mineral and metals’; ‘resource use, fossils’; ‘ionizing radiation, human health’; ‘climate change’; and ‘acidification’. Therefore, the actions that we recommend in the first place aim at reducing the impact of these components. They include limiting the mass of the raw material used in the antenna, changing the alloy of the antenna, considering another type of battery with an extended useful life, and the use of recycled materials for construction. As a pioneering study applying the LCA methodology to a large-scale physics experiment, this work can serve as a basis for future assessments by other collaborations.

Generalized Synthetic Control for TestOps at ABI: Models, Algorithms, and Infrastructure

We describe a novel optimization-based approach—generalized synthetic control (GSC)—in which we learn from experiments conducted in a physical retail environment. GSC solves a long-standing problem of learning from experiments conducted in this environment when treatment effects are small, the environment is extremely noisy and nonstationary, and interference and adherence problems are commonplace. The utilization of GSC has demonstrated a remarkable increase in statistical power, approximately one hundredfold (100×) higher than conventional inferential methods. This innovative approach forms the basis of TestOps, a pioneering large-scale experimentation platform designed specifically for physical retailers. TestOps was developed and has been broadly implemented as part of a collaboration between Anheuser Busch Inbev (ABI) and a team of operations researchers and data engineers from the Massachusetts Institute of Technology. TestOps currently runs physical experiments impacting approximately 135 million USD in revenue every month and routinely identifies innovations that result in a 1%–2% increase in sales volume. The vast majority of these innovations would have remained unidentified had we not developed our novel approach to inference. Prior to our implementation, statistically significant conclusions could be drawn on only ∼6% of all experiments, a fraction that has now increased by 10-fold. Given its success, TestOps is being rolled out globally at ABI, driving significant revenue growth and enabling the extraction of valuable insights from large-scale physical experiments. History: This paper has been accepted for the INFORMS Journal on Applied Analytics Special Issue—2022 Daniel H. Wagner Prize for Excellence in the Practice of Advanced Analytics and Operations Research.

Readout Electronics for the Zero Degree Calorimeter at HIRFL-CEE Experiment

The CSR External-target Experiment (CEE) at the Heavy Ion Research Facility at Lanzhou (HIRFL) will be the first GeV large-scale nuclear physics experiment developed independently in China. The primary physics goal of the CEE is to study the nuclear equation of state, hyper nuclei, and radioactive ion beam physics. The Zero Degree Calorimeter (ZDC) of CEE measures the centrality and reaction plane of the nuclear-nuclear collision relative to the hadron background. It consists of 192 roughly trapezoidal Plastic Scintillator (PS) crystal blocks coupled with PMT (Photo Multiplier Tube) to convert charged particles into electrical signals. The readout electronics consists of 12 FEE (Front End Electronics), the sub-trigger module, and the sub-clock module. In addition, one HV (High Voltage) crate provides a high voltage power supply for the PMTs. According to the electrical test on the electronics, the RMS (Root Mean Square) noise is less than 0.4 mV, and the nonlinearity is less than 0.06%. The heavy-ion beam test shows that the ZDC can measure particles up to Z=7, which meets the physics requirements.

Realization of Detector Control System of Physics Experiment

In order to meet the experimental requirements, modern physics experiments need to monitor a large number of indicators and give timely control commands. Considering the characteristics of large-scale physical experiments, including long-distance, various equipment and massive data, a distributed detector control system (DCS) was developed. It implements communication with non-standard hardware, data acquisition, alarm management and data archiving functions. A set of EPICS IOCs (input/output controller) is used to communicate with hardware. Because the electronics use IPbus as communication protocol, driver support is developed. The DCS implementation includes user interfaces, an alarm system, a data archiving system, and web services, among other things. At present, this DCS has been used by the experiment of Jiangmen Underground Neutrino Observatory (JUNO) to monitor the system status in electronics test. It provides the necessary reference for the technical route of large-scale monitoring.

Performance Investigation on a Clock Distribution and Synchronization Scheme Over DWDM Optical Links

For most large-scale physics experiments, it is desirable that the clock distribution and data transmission are unified on a single optical network. To meet the requirement of current large-scale physics experiments for clock synchronization accuracy in the range of tens of picoseconds, and adapt to the increasingly widespread use of dense wavelength division multiplexing (DWDM) optics, this paper investigates the performance of clock distribution and synchronization scheme based on DWDM optics and high-speed serializer-deserializer (SerDes) transceivers embedded in field programmable gate arrays (FPGAs). By extending our previously proposed simplified calibration procedure based on the White Rabbit protocol to the present asymmetric link, all possible errors, especially the new factors brought about by the asymmetric link, are investigated so that the time uncertainty on the link can be minimized. Using the built test system to carry out multiple Reset and long-term operation tests, the measured clock synchronization accuracy over a 5km optical fiber connection is better than 20ps, and the RMS jitter of the recovered clock is less than 10ps. The test results show that the combination of White Rabbit with DWDM optics can have both high-bandwidth data transmission and high-performance clock synchronization at the same time.

Effect of Fault Slip on the Casing Passability of Horizontal Shale Oil and Gas Wells

Summary Fault slip, a secondary effect of the hydrofracture to extract shale oil and gas, deforms the casing locally and affects downhole tools going through it, hindering the exploitation plan. The casing passability is introduced to evaluate the casing passability for the downhole tool. A simulation model of the fault slip was established to analyze the effect of fault type, slip distance, and fault dip on the casing passability. Meanwhile, the simulation method adopted in this paper was verified by the large-scale physical experiments of the perforated casing subjected to uniform outer pressure. Based on the experimental results and the geometry of fault slip, an empirical formula is proposed for the relationship between casing passability and fault slip. The result shows that the sensitivity of casing passability affected by fault type is ranked from highest to lowest by strike-slip fault, normal fault, and reverse fault. This study provides a reference for determining the available diameter of downhole tools quickly and reduces the cost of exploring wells when downhole tools are obstructed.

Techniques for improving fracture-controlled stimulated reservoir volume in ultra-deep fractured tight reservoirs: A case study of Kuqa piedmont clastic reservoirs, Tarim Basin, NW China

Based on analysis of the reasons for low efficiency and low production after fracturing of some wells in the ultra-deep fractured tight reservoirs of the Kuqa piedmont zone, Tarim Basin and the matching relationship between the in-situ stress field and natural fractures, technological methods for creating complex fracture networks are proposed. Through theoretical study and large-scale physical simulation experiments, the mechanical conditions for forming complex fracture network in the Kuqa piedmont ultra-deep reservoirs are determined. The effectiveness of temporary plugging and diversion, and multi-stage fracturing to activate natural fractures and consequently realize multi-stage diversion is verified. The coupling effect of hydraulic fractures and natural fractures activating each other and resulting in “fracture swarms” is observed. These insights provide theoretical support for improving fracture-controlled stimulated reservoir volume (FSRV) in ultra-deep tight reservoirs. In addition, following the concept of volume fracturing technology and based on the results of fracture conductivity experiments of different processes, fracturing technologies such as multi-stage fracture-network acid fracturing, “multi-stage temporary plugging + secondary fracturing”, fracturing of multiple small layers by vertically softness-and-hardness-oriented subdivision, and weighted-fluid refracturing are proposed to increase the FSRV. New environment-friendly weighted-fluid with low cost and new fracturing fluid system with low viscosity and high proppant-carrying capacity are also developed. These techniques have achieved remarkable results in field application.