Interference Zone Research Articles

Fatigue behavior of multi-row film cooling holes manufactured by lasers with different pulses under complex-temperature fields

This research investigates the fatigue behavior of multi-row film cooling holes produced by lasers with diverse pulse widths amid intricate thermal environments. Through laser drilling experiments, conjugate heat transfer simulations, and crystal plasticity finite element analyses, it explores the interplay of temperature and stress fields among multiple holes in these structures, and factors influencing fatigue damage and its severity. Additionally, it anticipates the fatigue fracture paths of multi-row film cooling hole structures. Findings reveal that while the drilling process and aerodynamic parameters significantly impact cooling effectiveness, their influence on cooling distribution is negligible. Fatigue damage distribution is shaped by structural imperfections from different processes, stress field interference among multiple holes, and material property alterations due to temperature changes. The extent of damage is primarily dictated by roundness errors resulting from the drilling process, with taper playing a minor role. Nonetheless, stress interference among multiple holes notably exacerbates stress concentration at the interference zone, leading to increased damage levels in film cooling holes crafted by picosecond lasers with minimal roundness errors. Moreover, in complex thermal environments, fatigue fracture paths of multi-row film cooling holes migrate and evolve contingent on temperature-induced shifts in material properties.

Adaptive MAC Scheme for Interference Management in Ad Hoc IoT Networks

The field of wireless communication has undergone revolutionary changes driven by technological advancements in recent years. Central to this evolution is wireless ad hoc networks, which are characterized by their decentralized nature and have introduced numerous possibilities and challenges for researchers. Moreover, most of the existing Internet of Things (IoT) networks are based on ad hoc networks. This study focuses on the exploration of interference management and Medium Access Control (MAC) schemes. Through statistical derivations and systematic simulations, we evaluate the efficacy of guard zone-based MAC protocols under Rayleigh fading channel conditions. By establishing a link between network parameters, interference patterns, and MAC effectiveness, this work contributes to optimizing network performance. A key aspect of this study is the investigation of optimal guard zone parameters, which are crucial for interference mitigation. The adaptive guard zone scheme demonstrates superior performance compared to the widely recognized Carrier Sense Multiple Access (CSMA) and the system-wide fixed guard zone protocol under fading channel conditions that mimic real-world scenarios. Additionally, simulations reveal the interactions between network variables such as node density, path loss exponent, outage probability, and spreading gain, providing insights into their impact on aggregated interference and guard zone effectiveness.

Depth dimension in seepage detection: Insights for exploration and geological gas storage surveillance

The search for surface hydrocarbon seeps has historically served as a fundamental tool in the early stages of oil and gas exploration. However, as easily detectable surface hydrocarbon seeps become increasingly scarce, advancement in analytical capabilities have shifted the focus towards detecting ultra-trace levels of hydrocarbons, commonly referred to as microseepages. While it is critical to understand the distribution of hydrocarbon microseepage for assessing petroleum systems and optimizing exploration efforts, the role of sampling depth in the detection of microseepage remains poorly understood. In this study, we investigated the influence of sampling depth on microseepage detection, using passive soil-gas sampling techniques at depths ranging from 0.5 to 10 m at sites with hydrocarbon-bearing reservoirs and dry wells. Organic geochemical analysis, including thermal desorption-gas chromatography-mass spectrometry (GC-MS), was employed to identify and quantify hydrocarbon and nonhydrocarbon compounds.The study result demonstrates that sampling at the Minimal Interference Zone (MIZ) depths of 5 m or greater significantly mitigates the risk of interference signals, thereby enabling the identification and quantification of hydrocarbon microseepages at trace and ultra-trace concentrations. At these depths, the attenuation of non-hydrocarbon compounds was observed, making the hydrocarbon signal markedly more distinguishable. Geochemical characterization of the samples revealed spatial and vertical heterogeneity in the distribution of hydrocarbon compounds, indicative of variations in the microseepage mechanisms potentially influenced by factors such as sedimentary basin settings and secondary alterations associated with the vadose zone. By utilizing passive soil-gas sampling techniques coupled with GC-MS, this study emphasizes the importance of sampling depth to improve the detection of reliable microseepage signal while reducing interference and background noise. The proposed technique not only refines existing methodologies for petroleum system assessments but also paves the way for broader geological applications. Specifically, the approach offers critical insights for the development of high-resolution geochemical surveys adaptable for surface background profiling in CO2 sequestration projects to monitor for storage efficiency and seal integrity.

The effect of forming surface interference on Thin-Walled profiles during the discontinuous forming process with discrete molds

This study aims to investigate the influence of the roller dies’ characteristics of shapes on the forming results in the roller-based flexible multi-point three-dimensional stretch bending forming (FSBRD) process for thin-walled profiles, as well as the prediction of mold-induced impressions during the FSBRD process. Considering the specific contact mode, an L-shaped section profile’s flange was selected as the research object to analyze the impact of the roller dies’ slot’s geometric parameters on the product. A classification model of the contact between the profile’s flange and the roller die was established for the vertical bending process, and the maximum theoretical interference value (imax) was calculated to predict the extent of local deformation after contact. Subsequently, finite element software was used to model the process and analyze the changes in equivalent plastic strain (PEEQ) of the deformation results when using roller dies with slots of different parameters, including straight, inclined, and arc-shaped slots. The analysis results indicate that the width of the straight slot has a significant influence on the forming quality of the product, as a smaller slot width leads to larger local dimples on the product surface. Replacing the straight slot with an inclined or arc-shaped slot improves the abrupt changes in local PEEQ, resulting in reduced macroscopic local dimples. The simulation results align with the analytical model’s variation of imax. This study defined the theoretical contact angle γ and introduced the concept of the contact area and the local theoretical interference zone, providing a reasonable explanation for the observed PEEQ variations. Furthermore, based on the conclusions of the research above, modified experiments were designed, resulting in favorable forming effects. The validation of the simulation results was performed by comparing the local dimples in the contact zone of the actual experimental results.

Research on the penetration performance of shaped charge jet into block stone concrete targets

Experiment and numerical simulation were conducted to investigate the penetration performance of shaped charge jet into block stone concrete targets. The experiment has shown that the jet undergoes deflection and other phenomena during its penetration of block stone concrete. Improvements have been made to the methods used by previous scholars for constructing aggregate particles, resulting in a particle model that more closely resembles the true shape of the aggregate. A novel method for judging the intersection of aggregate particles based on the Plucker coordinate system was proposed. In comparison with traditional methods, this method is not constrained by the shape of aggregate particles. By utilizing dynamic simulation software to replicate aggregate settlement during the production process of concrete targets, a 3D meso-scale model of concrete was successfully established. Numerical simulations were conducted according to the experimental settings, with the results demonstrating good consistency between the experimental and numerical simulations, thus confirming the reliability of the model and methodology presented in this article. Additionally, the numerical simulation results suggest that the aggregate content significantly influences the degree of interference, penetration depth, and damage zone range of the jet, while the impact position primarily affects the deflection of the jet. This article provides a numerical simulation method for future research on the penetration and damage mechanism of shaped charge jet considering the 3D meso-scale model of concrete.

Experimental study on the heat flux of transitional shock wave–boundary layer interaction at Mach 6

The shock wave–boundary layer interaction (SWBLI) phenomenon was investigated experimentally to explore the heat flux distribution characteristics of SWBLIs under different boundary layer flow regimes and the influence/mechanism of different transition positions on peak heat flux of SWBLI. Experiments were conducted in a flow of Mach number 6. The shock generator deflected the flow by 20 °, 22 °, 25 ° and 30 ° resulting in an oblique shock impinging on a flat plate. The rough elements with different heights were arranged to achieve different transition positions. The influence of the relative position of transition and interference zone on the peak heat flux and its physical mechanism are revealed. The results demonstrated that the transitional SWBLI has a higher peak heat flux than the turbulent SWBLI, however the overshoot phenomenon is not reflected in the peak pressure. The increment of heat flux peak in transitional SWBLI is related to the relative positions of transition and interference zones. The increment of heat flux peak of transitional SWBLI compared to turbulent SWBLI can reach 25.5–38.9% and 51.9–65.1% when transition approaches the separation zone and reattachment zone, respectively. This overshoot phenomenon is caused by the streamwise vortex in transitional and so-called laminar SWBLIs, which enhances the energy exchange in the boundary layer and leads to an increase in heat flux. However, in the turbulent SWBLI, the energy mixing in the boundary layer is not significantly enhanced due to the breakup of the large scale streamwise vortex into turbulent small-scale structure.

Algorithm for Surface Wave Suppression on 2D Seismic Data Using the Slant Karhunen–Loeve Transform in a Time-Frequency Domain

Abstract —Surface waves are the main source of coherent noise in land seismic survey, and their suppression is one of the main stages of common depth point data processing designed to improve the quality of tracking primary reflections on time sections. In practice, noise reduction is carried out using procedures from modern software based on numerical modeling of waveforms. However, they are too resource-intensive and have a large number of subjectively customizable parameters. The known algorithms have a common drawback: either the energy of reflected waves is distorted in an interference zone with a noise wave or the noise suppression quality is unsatisfactory. The current research is aimed at improving the filtering algorithm in a time-frequency domain using the slant Karhunen–Loeve transform in order to overcome these limitations, to increase the accuracy and rate of its software implementation, and also to test it when processing profile field data from land-based 2D seismic surveys. The algorithm is modified by developing a new method for determining static corrections for surface wave hodograph rectification in a time-frequency domain and by the application of preprocessing in which the reflected wave signal is removed preliminarily. These and other modifications ensure faster calculations and improve the quality of surface wave interference suppression. In addition, the slant Karhunen–Loeve transform is accelerated by parallelizing calculations across logical processor cores. In this paper, the algorithm is described in detail, its significant advantage over the standard methods of bandpass filtering and F–K filtering is shown, and the results of processing the field data obtained by the SWANA procedure (Geovation 2.0) and by the slant Karhunen–Loeve transform. The result obtained by the slant Karhunen–Loeve transform is superior to the SWANA procedure in terms of the surface wave filtering quality and has only four adjustable parameters (SWANA has 20 parameters)

Damageability of Metals under Impulse Loading

Impulse loading of a sample of limited dimensions (at least two free surfaces) leads to the oscillation of the sample in the standing wave mode as a consequence of wave reflection from the faces and their interaction with each other. Localized strain bands originate and evolve at the standing wave nodes (wave interference zone), where the deformation of the material occurs in the compression-tension mode and the stress in the wave interference zone does not exceed the spall strength of the material. (Excessive stress leads to the formation of spall cracks and sample destruction). As a result of the absence of energy transfer through the nodal points,which is typical of standing waves, the deformation of the sample can last for a long time after passing a shock wave until dissipative processes would bring about oscillatory process damping. Another characteristic feature of standing waves is the formation of new harmonics with their own wavelengths and vibration eigen frequencies with new spall damage occurring at each node.

Into an interference zone: childbirth and care among Mehinako people

Into an interference zone: childbirth and care among Mehinako people

Evolution mechanism of flip-fold removal behaviour through crossed scratching of glass-ceramics

In this study, a novel flip-fold removal model was established to reveal the ductile–brittle mixed removal phenomenon in the grinding process of glass-ceramics. This flip-fold model proposed for the ductile–brittle mixed removal mode differs from conventional brittle or ductile removal mechanisms. Using the theoretical exploration method, a theoretical model of flip-fold removal is established based on the analysis of different scenarios of the relationship between the depth of the stagnation region and pile-up height of the interference zone. Through an experimental verification method, the approach of crossing double scratches with a continuously variable scratch distance is proposed to observe the evolution progression and verify the flip-fold removal model. Using the analytical analysis method, the amplitude and direction cosine distributions of the interference stress field were analysed to reveal the internal mechanism of the flip-fold removal model. The results of the three scientific research methods were in good agreement with those of the proposed model. The flip-fold material removal model supports the comprehension of the ductile–brittle mixed removal mode during the grinding of hard-brittle materials. This model provides an approach to controlling the material removal mode from the perspective of regulating the flip-fold behaviour by adjusting the scratch distance.

Modern geodynamic systems of the Urals in relation to seismicity

Modern geodynamic systems of the Urals are studied in connection with the uneven distribution of seismic activity. The neotectonic zoning and geodynamic conditions of its formation in the Southern and Middle Urals and adjacent platform territories were studied in connection with the Katav-Ivanovo mediummagnitude earthquake occurred in 2018. The epicenter was located outside the known zones of possible seismic sources, which required additional research to determine the causes of the earthquake. As a result of near-surface and deep research the Uraltau-Magnitogorsk and Osinsko-Bolsheusinskaya geodynamic systems have been established, which are the cause of the transverse segmentation of the Urals and, possibly, one of the factors of seismic activity. The geodynamic systems are inconsistently articulated with each other with the development of the Birsko-Karatau geodynamically active zone and the Katav-Satka interference zone. The earthquake is associated with the Katav-Satka interference zone. The interference zone has been investigated with respect to fracturing and slickenlines. Orientations of modern stresses induced from the active regions are estimated. Modern stresses are the reason for the activation of the Zilmerdak from the beginning of the Late Paleozoic overstep and, as a consequence, the Katav-Ivanov earthquake. Earthquakes caused the development of secondary dangerous seismogenic phenomena and deformation of buildings.

Research on a Ship Deflection Anti-Collision Method Based on a Water-Jet Interference Flow Field

Currently, water jets are mainly used in the fields of mechanical processing and mining collection. This paper creatively introduces them to the field of safety assurance for inland navigation. Compared with the traditional bridge anti-striking methods such as intelligent early warning and passive anti-striking, this method can form an “interference zone” by changing the water flow conditions in the local bridge water areas, causing the yawing moment of the yaw ship to change, thereby causing the ship’s course to change, and thus guiding the ship to move away from the bridge pier to realize active anti-striking of the ship. In this paper, a combination of generalized model testing and numerical simulation was used to study the effects of different nozzle pressures and different ship pier distances of the water-jet generator on the trajectory and drift angle of the stalled ship. The results showed that the numerical simulation was in good agreement with the model test results. Within the interference zone, the distance between the ship and the pier increased rapidly after the action of the disturbance zone to 9.1, 5.8, and 6.2 times the ship’s width, respectively, reaching a safe distance. During the process of being affected by the interference zone, the maximum drift angle of the yaw ship was less than 20°, the course of the ship was generally stable, and the drift angle comparison error was a maximum of 10.6%, a minimum of 3.5%, and an average error of 6.7%. A negative peak and a positive peak of four times the absolute value of the negative peak occurred in the yaw-moment ephemeral curve during the ship’s passage through the interference area. The method had a notable effect on the anti-striking of stalled ships and two invention patents applied for in the course of research.

Performance analysis in overlay-based cognitive D2D communications in 5G networks

With the advent of fifth-generation 5G networks, mobile communication data rates are steadily rising. The existing base stations (BSs) must reduce the loads with minimal cost and effort. With traffic demands constantly rising, available spectrum resources must be utilized effectively. One of the most exciting developments in 5G networks, particularly cellular networks, is the potential for devices to communicate directly with one another through a technology called device-to-device communication (D2D). With the transmission split between D2D users on one side and cellular users and the BS on the other, it will be effective in the rapidly expanding capacity and offload traffic from the BS. With the dynamic spectrum access in mind, this article proposes using cognitive radio direct-to-device (CRD2D) communication in 5G networks to make use of the unused spectrum. Throughput and latency are examined, for a carrier sense multiple access (CSMA) based medium access control (MAC) protocol that uses a common control channel (CCC) for device users to negotiate the data channel and to address contention among device users. Device users can take advantage of cognitive radio to access multiple data channels simultaneously in a shared interference zone. Since this property has not been utilized, in prior works, we use it to measure the possible delay and throughput. Cognitive radio capability applied to D2D communication and the allocation of a common control channel for device users significantly increases aggregated network throughput by more than 60% compared to individual D2D throughput without causing any harmful interference to cellular users. The wait time can also be scale back using this method.

AELH-, CFD-, and ANN-based wind interference zone prediction of regular tall buildings

AELH-, CFD-, and ANN-based wind interference zone prediction of regular tall buildings

Adaptive behavior in sonar prey tracking tasks: Empirical data and modeling

Echolocating bats can discriminate small differences in target range (Simmons, 1973) and show a clutter interference zone along the range axis of 8–9 cm (Simmons et al., 1988). Because bats use an active sensing system, they can employ various strategies to mitigate the effects of clutter. We studied clutter rejection behaviors of the big brown bat, Eptesicus fuscus, as it tracked a moving target under controlled conditions. We also created data-driven models using control theory and system identification techniques to evaluate oscillating target motion tracking strategies. We trained bats to rest on a stationary platform and track a moving tethered mealworm in two conditions (1) approaching and passing by stationary clutter objects at varying distances and angular offsets, and (2) moving in sinusoidal patterns in an open room. Data from the first experimental condition revealed adaptive echolocation call features and head movements that enabled target tracking in the presence of clutter. Under the oscillating target condition, we analyzed adaptive echolocation behavior to create a data-driven model that maps changes in target motion with sonar call rate. The results of this study demonstrate the bat’s use of active motor control that separates targets from clutter and to track complex motion trajectories.

The Multiple that Occupies Space Expanded Field Graphics


 
 
 The conceptual and practical frontiers of art today have been erased due to the triumph of complex thought theories and the incorporation of new technological processes that have led artists to position their creations in interference zones.
 The formal, technical and conceptual approaches that were previously unitary in graphics have been reformulated in pursuit of art that can be viewed from the actual process of multiplication and multiplexing. Graphics, as we understand them today, are much more hybrid and complex when installed in space. This displacement of the print has raised new questions and induced some answers concerning the idea of the matrix that generates “multiples”. The multiple-concept view takes us back to the multifaceted XXI century in a mutant invasive loop that colonises the boundaries of the very definitions.
 The objective of this paper is to reflect on how the classical two-dimensionality of graphics has moved towards the search for a deeper and more immersive artistic experience, different from what we have known to date. We will observe how multiple art has evolved from the two-dimensional traditional paper print to the sculptural object and by extension to its installation in space. We start from that inhabited, printed flat space to add other elements to the third dimension that will define our understanding of the new multiple reality: the time element concerning the experiential perception element of the work of art.
 
 

Numerical Investigation and Experiment on Natural Circulation Resistance and Energy Characteristics in a Circulating Axial Pump

Abstract The influence of angle matching in rotor–stator interference (RSI) zone on natural circulation resistance (NCR) of circulating pump in natural circulation condition is illustrated by numerical method, and the analysis and optimization method of natural circulation based on loss coefficient curve are established through experiments. The mechanism and analysis formula of runaway speed are extracted, and the distribution diagram of Euler head density function (EHDF) is obtained to carry out image processing and analysis of secondary flow. Then, the optimal design interval of setting angle of impeller outlet under low flow resistance is acquired. As for the natural circulation loss of static parts, the optimal design interval of guide vane inlet angle and outlet angle with low flow resistance is obtained by analyzing the EHDF distribution diagram of the whole flow parts, which accounts for the position and reason of resistance. In this paper, the mechanism between runaway speed and loss coefficient curve is revealed and the resistance is optimized through the design and analysis of the RSI region, which provides theoretical methods for the analysis of the impeller performance of axial-flow circulating pump. Furthermore, it is a reference for the optimization design of natural circulation system.

Deepwater fold-thrust belt contraction driven by mixed deformation components

The formation of fold-thrust belts is driven by compressive stresses caused by crustal tectonics, gravity, or a combination of both. The formation mechanism of a single compressive stress component has been thoroughly investigated by laboratory experiments and field observations. It is yet less well established how fold-thrust systems deform under multiple compressional stresses. The formation of the deepwater fold-thrust belt on the northwest Borneo margin has been previously explained by compressive gravity-driven stresses in the south and crustal-driven tectonics in the north. This study focuses on the transition zone between the gravity-driven south and crustal-driven north, and investigates the structural diversity around this transition using 3D seismic-reflection data. Structural interpretation results reveal two structural provinces distinct in deformation styles and structural kinematics within the deepwater fold-thrust belt. Folds and thrusts in each structural province reflect deformation stresses that occurred at different times with different orientation. Structural features in each structural province developed independently and were preserved largely without mixing in the fold-thrust belt, except for an interference zone of ca. 15 km in width. The fold-thrust belt can be interpreted to have formed by a multi-directional compressive stress system and exhibits greater structural heterogeneity than deformation caused by a single-component compressive stress system. Particular deformation characteristics and fault activity in the interference zone reflect a complex disparate compressive stress relationship.

Mitigation of blast loading through blast–obstacle interaction

Obstructing the passage of blast waves is an effective method of mitigating blast pressures downstream of the obstacle. To this end, the interaction between a blast wave and a simplified structural shape, such as a cylinder, has been widely investigated to understand the complex flow pattern that ensues around the obstacle. The patterns include the interference zones of the incident wave, the diffracted wave, and other secondary waves in the downstream region. Such zones are responsible for causing significant modifications to the blast wave parameters. This research aims to identify and study the factors that serve to mitigate the resulting blast loads downstream of a cylindrical obstacle – both on the ground, and on a rigid wall target that the obstacle is aiming to protect. Inputs from this numerical study are also used to develop a fast-running predictive method based on an artificial neural network (ANN) model. It was found that the size of the cylinder, the strength of the blast wave, the position of the cylindrical obstruction, and the target length, all have remarkable effects on the development of the complex flow-field downstream, and on the impulse mitigation on a reflective target. A number of key mitigation mechanisms are identified, namely shadowing and interference, and their origins and significance are discussed. An ANN model trained using scaled input parameters could successfully predict impulse values on such a reflective target. Using this model to predict the response of previously unseen configurations (for the ANN) gave excellent correlation, thereby demonstrating the high fidelity of this fast-running tool, and its ability to predict the effectiveness of various wave-cylinder interactions in mitigating blast loading.

Numerical and Experimental Study on the Effect of Rotor–Stator Distance on Rotor–Stator Interaction Strength within Mixed-Flow Centrifugal Pumps

In this article, the influence of rotor–stator distance on the pump performance and rotor–stator interaction strength within mixed-flow centrifugal pump was investigated based on numerical calculation and test verification. Firstly, the performances of mixed-flow centrifugal pumps with two different rotor–stator distances were obtained and compared with the numerical results, which confirms the high accuracy of the numerical simulation. Next, the performances of mixed-flow centrifugal pumps with five different rotor–stator distances were compared and analyzed. It was found that the hydraulic performance of the mixed-flow centrifugal pump varies slightly as the rotor–stator distance increases. The mean values of the standard deviation of the head and efficiency of the mixed-flow centrifugal pump at each rotor–stator distance under full flow conditions are only 0.16 m and 0.11%, respectively. Then, the strengths of the rotor–stator interaction with different rotor–stator distances were analyzed. It was found that the strengths of the shock interaction, the wake interaction, and the potential interaction were all reduced with increasing rotor–stator distance. Moreover, when the rotor–stator distance is 1.5 mm, the pressure distribution in the circumferential direction of the rotor–stator interference zone shows obvious unstable characteristics: the pressure change amplitude is significantly greater than the other rotor–stator distance of the pressure change amplitude, the maximum and minimum pressure amplitude difference being 56.9 kPa, and with the increase in the rotor–stator distance, the maximum and minimum pressure amplitude difference gradually decreases, with an average value of 32.3 kPa. These findings could provide useful insight into prospects for the improvement of the operational stability of mixed-flow centrifugal pumps, and the results of this study can be extended to all centrifugal pumps using diffusers in the form of vanes as the pressure chamber, which has strong practical application and theoretical value.