Thrust Reverser Research Articles

Study of the Aerodynamic Characteristics on the ‎Computed Flowfield During Thrust Reversers Operation

With the increasing of the bypass ratio of modern aero-engines, the problem of wing-engine interference is more prominent, especially for the layout design of engine nacelle. The reverse thrust cascade is widely used in turbofan engines with high bypass ratio. In order to meet the requirements of the integrated analysis of airframe, wing, engine nacelle and hanger, the aerodynamic characteristics of aircraft/engine integration configuration with reverse cascade is numerically studied via CFD (Computational Fluid Dynamics) method. The streamline distribution, iso-surface of total temperature, vorticity distribution and total reverse thrust efficiency on different engine nacelle layouts are compared and analyzed in details. The results show that the lift coefficient of the wing decreases by 21.2% and 45.02% respectively as the engine moves forwards horizontally by 11%L and 21.2%L. The lift coefficient of the wing decreases by 2.4% and 4.82% respectively as the engine moves subsidence by -3.5%L and 3.5%L. The influential region of the reverser airflow in the radial and circumferential direction without airframe interference is significantly larger than that in the case with aircraft/engine integration. The reverser flow is susceptible to be interfered by the adjacent fuselage and wing sections, and the development of reverse thrust flow is significantly limited. Compared to the baseline nacelle location, the reverse thrust performs badly as engine nacelle moves backward and lateral horizontally. The total reverse thrust efficiency decreases gradually as the engine nacelle moves forward horizontally.

Analysis and experimental research on motion stability of wall-climbing robot with double propellers

This paper presents a wall-climbing robot which can stably hold and move on the ground-wall surface. The robot uses propeller reverse thrust as an adsorption force and can adapt to the surface of several media materials. The influence of the robot’s structural parameters on its power system is analyzed by comparing a single power system test and a robot prototype power test. A structural analysis of the robot is performed under two specific situations; when he is in transition from the ground to a small slope, and when he is on the slope. The force state of the robot is then obtained in different conditions. Experimental results show that the adjustment range of different rotor inclination angles of the robot, the width of the fixed rotor plate and the different near-ground distances, affect the traction of the robot. The robot motion performance and adaptability under different ground/wall environments are analyzed, by conducting the robot climbing experiment under a small slope, a vertical wooden wall surface and a vertical indoor wall surface. Stable adsorption and optimization tests are also performed. Moreover, the stability of the robot’s motion is verified. Finally, a theoretical and experimental accumulation is laid for the realization of the smooth transition of the robot from the ground to the wall.

Research on Deep-Site Failure Mechanism of High-Steep Slope under Active Fault Creeping Dislocation

The reverse thrust in the deep site causes the upward propagation of stress and displacement in the overlying soil. The displacement field around the fault zone is maximum. As the spatial location becomes shallower, the soil displacement gradually becomes smaller. The deformation of the overlying soil is mainly affected by the vertical dislocation of the fracture zone. The monitoring curve showed no abrupt change value, indicating that the top surface of soil did not rupture, and only the influence of fault on the displacement transfer of the top surface of the soil. When a creeping dislocation occurs in the bottom fracture zone, the maximum principal stress of the upper boundary of the deep site is dominated by compressive stress. The maximum principal stress of the soil on both sides of the fracture zone has a maximum value, and the soil on the right side of the fracture zone has a significant compression effect. The maximum principal stress monitoring curve varies greatly, indicating the plastic failure development of soil, which is the same as the research results of the plastic failure zone in the following paper. When the bottom fracture zone starts to move, the plastic zone first appears at the junction area between the front end of the bottom fracture zone and the overlying soil. As the amount of dislocation of the fracture zone increases, the plastic zone continues to extend into the inner soil. The left and right sides of the fracture zone show tensile failure and compression failure, respectively. The development of the upper envelope curve in the plastic zone of the overlying soil satisfies the Boltzmann equation with a first-order exponential growth, while the development of the lower envelope curve satisfies the Gauss equation with a second-order exponential growth. The development curve equation of the plastic zone is verified according to the residual figures of the fitting result and the correlation parameters.

INTERPRETAÇÃO SÍSMICA E MODELAGEM 3D ESTRUTURAL NA BACIA DE BARREIRINHAS (MARANHÃO, BRASIL)

Discoveries of hydrocarbons in the basins of the African Equatorial Margin and Guinea Gulf stimulated the exploratory interest in the basins of the Brazilian Equatorial Margin, for being together before the Continental Drift. This interest emerges because both African and South American equatorial margin are considered analogous. The Barreirinhas Basin is a member of the Brazilian equatorial margin. The objective of this work is to present the results obtained through the seismic interpretation and structural 3D modeling, in the context of gravitational tectonics, in an area covered by 3D seismic data, in the Barreirinhas Basin. The compressional domain of an extensive-compressive system was mapped. In this study, were identified reverse faults, thrust faults and fault-related folding like fault-bend and fault-propagation fold that can be accompanied by backthrust features in deep to ultra-deep waters. The 3D structural model allowed the representation of the geometric variations present in the study area. The new information will be important for the identification and evaluation of structures with greater potential for hydrocarbon accumulations and can help in future studies to characterize the reservoir, contributing to the evolution of knowledge of the equatorial margin, especially in the Barreirinhas Basin.

Bidirectional growth of the Altyn Tagh Fault since the Early Oligocene

The Cenozoic evolution of the Altyn Tagh Fault (ATF) is still under debate. Here, we present new paleomagnetic rotation evidence on curvatures south of the ATF in the northeastern Tibetan Plateau to shed new light on this issue. A total of 498 core samples representing 53 sites and 6 time intervals (a-f) were collected from the post-Oligocene sequence at the Heishiqiu locality that in the junction of the northwestern and middle of the reverse S-type northern Qaidam marginal thrust belt. Rock magnetic analysis indicated that the main magnetic carriers were hematite and magnetite. After detailed thermal demagnetization analyses, the characteristic remanent magnetizations of 48 sites (387 samples), which exhibited dual polarities and passed a regional fold test, are most likely the primary magnetizations. Two periods of remarkable rotations are identified at Heishiqiu: a clockwise rotation of ~16.0 ± 10.3° during ~27–17 Ma and a subsequent counterclockwise rotation of ~24.3 ± 14.5° during ~17–10 Ma. The rotations were attributed to two periods of strike-slip faulting along the ATF during the Early Oligocene to Late Miocene, yielding at least ~290–380 km of offset at Heishiqiu. The integrated lines of paleomagnetic and geological evidence suggest that the deformation along the ATF has propagated both southwestward and northeastward from Heishiqiu in the middle ATF since the Early Oligocene. We propose a bidirectional growth model for the ATF that might be applicable to the evolution of the Tibetan Plateau.

Experimental study on load rejection process of a model tubular turbine

To obtain the dynamic parameters variation characteristics of a model tubular turbine during the load rejection process, a model test method was designed and carried out in this paper. Firstly, the model test system, the test method and the model tubular turbine parameters were introduced. Then, the experiments of different schemes were performed and the results were analyzed. Evidently, the closing rules of guide vanes and runner blades have influence on the quality of transient process. When the guide vanes undergo linear needle closure law, the effect of prolonging the blade closing time on reducing the maximum speed appreciation and the maximum reverse water thrust is obvious, and when the guide vanes is closed in two stages, the longer the blade closing time, the lower the maximum reverse hydraulic thrust value. With the same closing law, the segmental closure law with guide blade first fast and then slow is more obvious than the linear needle closing law in reducing the maximum reverse water thrust, and the selection of closure segment point of guide vanes has a certain effect on the appreciation of the maximum rotating speed. Thus, the model test method could be used in transient operation improvement at hydropower plants.

Flow Distortion Into the Core Engine for an Installed Variable Pitch Fan in Reverse Thrust Mode

Abstract The flow distortion at core engine entry for a variable pitch fan (VPF) in reverse thrust mode is described from a realistic flow field obtained using an integrated airframe-engine model. The model includes the VPF, core entry splitter, complete bypass nozzle flow path wrapped in a nacelle, and installed to an airframe in landing configuration through a pylon. A moving ground plane to mimic the rolling runway is included. 3D Reynolds-averaged Navier–Stokes (RANS) solutions are generated at two combinations of VPF stagger angle and rotational speed settings for the entire aircraft landing run from 140 to 20 knots. The internal reverse thrust flow field is characterized by bypass nozzle lip separation, pylon wake, and recirculation of flow turned back from the VPF. A portion of the reverse stream flow turns 180 deg with separation at the splitter leading edge to feed the core engine. The core engine feed flow exhibits circumferential and radial nonuniformities that depend on the reverse flow development at different landing speeds. The temporal dependence of the distorted flow features is also explored by an unsteady Reynolds-averaged Navier–Stokes (URANS) analysis. Total pressure and swirl angle distortion descriptors, as defined by the Society of Automotive Engineers (SAE) S-16 committee, and, total pressure loss into the core engine are described for the core feed flow at different operating conditions and landing speeds. It is observed that the radial intensity of total pressure distortion is critical to core engine operation, while the circumferential intensity is within acceptable limits. Therefore, the baseline sharp splitter edge is replaced by two larger rounded splitter edges of radii, ∼0.1x and ∼0.2x times the core duct height. This was found to reduce the radial intensity of total pressure distortion to acceptable levels. The description of the installed core feed flow distortion, as described in this study, is necessary to ascertain stable core engine operation, which powers the VPF in reverse thrust mode.

Development of Instrumentation Adapted by C.M.M.S. Dedicate to Poly-articulated Mechanisms

Abstract: In this article three study phases have been discussed: Landing phase of a civil transport aircraft,when part of the flow entering the reactors is redirected by thrust reversers. Phase of the functional andtechnical study of which reflects on the aircraft maintenance component, without forgetting the phase ofsynthesis of the landing system mechanisms. The approach presented relates to the description of thedifferent instruments and languages used for the control of vibratory behavior in a maintenance plan. Activedevices are used mainly in systems where the excitation acts permanently on the system and the minimizationof the amplitude of the vibrations is the dominant criterion. This is the reason why it is important to plan andcontrol the technical aspect which will contain the landing system from the point of view of geometry, torques,positions, speeds and accelerations, and trajectories from the mechanism design phase.Keywords: Synthesis of mechanisms, Measurement and Instrumentation, CAD Prototype

Understanding Influence of Powerplant Component Connection Strategies on Aircraft Engine Structural Deformations

In conventional aircraft design, engine loads are transferred directly from the engine core and fan case to the pylon via engine mounts. Literature is available on the modeling of individual powerplant components, but limited work is available on the whole assembled system (engine, pylon, and nacelle). The influence of the structural connections between the components on overall system performance has not been investigated. Herein, a finite element model is described and can be used to assess connection strategies between powerplant components and if such arrangements can effectively enhance engine performance by reducing detrimental engine structural deformations (engine carcass bending, rotation, and ovalization). The method is demonstrated for a generic high bypass ratio engine design, focusing on connections between the engine and thrust reverser unit. The method identifies a modified attachment scheme between the engine rear turbine casing and the inner barrel of the thrust reverser unit, which reduces engine deformations across multiple loading scenarios. Maximum reductions of 97 and 96% have been observed in carcass bending and ovalization, respectively.

Computer simulation of heat transfer processes in aircraft landing gear braking mechanisms

Landing gear brakes – multi-disc brakes, as the responsible mechanism of the aircraft, must have the lowest possible weight and dimensions, high performance, increased service life and reduced life cycle cost. Solving these problems will reduce the design and development cycle of multi-disc chassis brakes. To perform the calculations, a computer mathematical model based on the use of the finite element method is proposed, replacing the classical version of the calculation based on currently used mathematical models, taking into account the heating of the aircraft landing gear braking mechanism, which will increase the speed, accuracy of calculations and reduce their labor intensity. We have developed a computer mathematical model of heat transfer processes occurring in the friction elements of multi-disc landing gear braking systems at the second stage of landing using the COMSOL Multiphysics program. Based on the calculations performed using this model, it is possible to take into account the influence of various system parameters such as the number of friction disks, their diameter and thickness, the medium in the interstitial space, the size of the solver grid on the maximum heating temperature of the brake mechanism, the cooling rate, the calculation time and the calculation error. On the basis of the obtained experimental data, we can conclude about the preferable construction of the brake mechanism. For example, it is possible to produce friction plates, steel with application to the surface of the composite friction material, allowing it to maintain the necessary friction and thus reduce the dimensions and maximum temperature, wet-disc brakes. The results of this work can be applied not only in the aviation industry, but can also be used to calculate the mechanisms of multi-disc oil-loaded brakes, which are used in agricultural, forestry, construction, quarry and other special equipment. In future work, the developed model will allow carrying out calculations taking into account the changes of material properties depending on temperature, refining the geometry of the brake mechanism, taking into account periods of reverse thrust engines and aerodynamic brakes.

Landing the Booster Using Parachute

This Paper involves designing, testing, construction and launching of rocket. The high cost of rocket technology has led to system reusability developments, particularly in the field of first stage rockets. With the motivation of decreasing production costs, successful vertical rocket landing attempts by Space X and Blue Origin have led the path for autonomous recovery and reusability of rocket engines. Landing an autonomous spacecraft or rocket is very challenging, and landing one with precision close to a prescribed target even more so. Precision landing has the potential to improve exploration of our solar system, and to enable rockets that can be refuelled and reused like an airplane. This paper aims to develop a vertical rocket landing simulation by parachute and reverse thrust methods. This paper will discuss the challenges of precision landing, recent advances that enabled precision landing on Earth for commercial reusable rockets, and what is required to extend this to landing on planet.

Design and Stability Analysis of a Wall-Climbing Robot Using Propulsive Force of Propeller

This article introduces a wall-climbing robot that uses the reverse thrust of the propeller as the adsorption force. The robot is symmetrically distributed in structure and the adsorption force is symmetrically distributed before and after so that it can adapt to the surface of a variety of different media materials and achieve stable adsorption and movement of a variety of wall surfaces. The robot mainly uses the reverse thrust of the aircraft propeller as the adsorption force to achieve wall adsorption. The robot relies on four wheels to move forward. The forward power mainly comes from the combined action of the propeller reverse thrust component and the front wheel driving force. During the movement of the robot, the steering is realized by the front wheel differential control. In this paper, we design the structure of a dual-propeller dynamic adsorption wall mobile robot, plan the movement process of the robot from the ground to the wall, analyze the stable adsorption conditions of the robot wall, and carry out the robot’s motion performance and adaptability test under different ground/wall environments to verify that the robot is stable and feasible.

Influences on the extended length and performance of push bending for the GH4169 superalloy tube with small bending radius of 1D

It is extremely difficult to eliminate the defects like wrinkling, which is generated in the bending of tube with small bending radius. In this thesis, the push-bending process of the GH4169 superalloy tube with a large diameter-thickness ratio of 60 and small bending radius of 1D is studied by numerical simulations and experiments, aiming to eliminate wrinkles on the inside of the tube and obtain enough extended length (e) of straight segment as well as minimal changes in the wall thickness. Three influencing factors, such as the inclined angle (α) at the initial end, the reverse thrust (P) of polyurethane blocks, and the lubrication, are investigated in the simulation. According to the simulations, the proposed experiment is successfully implemented on an independent development of push-bending equipment. The results are in good agreement with the simulation. The optimum parameters for the GH4169 superalloy alloy tube with a large diameter-thickness ratio of 60 and small bending radius of 1D are simulated. And then α is optimized to 45° and P is optimized to 48 MPa. And differential lubrication is used for longer extended length of straight segment and more uniform distribution of wall thickness on both sides of the deformed elbow.

Сравнительный анализ технологических методов раздачи трубчатой заготовки

A significant problem in the aircraft industry remains the production of reliable hydro-gas systems, such as flight control, landing gear retraction and release, wheel turn control of the front landing gear, control of air brakes and spoilers, engine thrust reversal control, et al., providing a high degree of performance and reliability. The article discusses the technological processes of manufacturing parts for hydro-gas systems of aircraft. Research has been carried out on the expansion of the middle part of thin-walled tubular billets by cold plastic deformation, which showed that the most dangerous is the middle part of the considered part of the billet, where there are significant tensile stresses. The reduction in tensile stresses that occurs when creating an ice retainer allows to increase in the expansion ratio. The application of new types of working bodies is proposed for transferring pressure to the deformation zone.

Improving Multirotor Landing Performance on Inclined Surfaces Using Reverse Thrust

Conventional multirotors are unable to land on inclined surfaces without specialized suspensions and adhesion devices. With the development of a bidirectional rotor, landing maneuvers could benefit from rapid thrust reversal, which would increase the landing envelope without involving the addition of heavy and complex landing gears or reduction of payload capacity. This letter presents a model designed to accurately simulate quadrotor landings, the behavior of their stiff landing gear, and the limitations of bidirectional rotors. The model was validated using experimental results on both low-friction and high-friction surfaces, and was then used to test multiple landing algorithms over a wide range of touchdown velocities and slope inclinations to explore the benefits of reverse thrust. It is shown that thrust reversal can nearly double the maximum inclination on which a quadrotor can land and can also allow high vertical velocity landings.

Fluvial terraces as quantitative markers of late Quaternary detachment folding and creeping thrust faulting in the Peruvian Huallaga basin

In the western Huallaga basin, located in the Peruvian Subandes, a series of nine fluvial terraces with elevations of up to 160 m above current floodplain level (+FP) were formed against the Biabo anticline. The terraces are progressively more folded with age and terrace elevation and present growth strata, suggesting ongoing folding of the anticline. Optically and InfraRed Stimulated Luminescence (OSL and IRSL) dating of fluvial terrace sediments yielded ages of 10.8 ± 0.7 ka for the T2, 24.2 ± 2 ka for the T4 and 46 ± 9 ka for the T7 terrace. Uniform uplift rates of 2 mm a−1 for the past 46 ka were calculated. Terrace profiles and two new seismic profiles that cross the Biabo anticline longitudinally and transversally were used to calculate shortening rates of 2.6 mm a−1 for the anticline over the past 46 ka. Our calculations took into account potential contributions of detachment thrusting parallel to the Biabo fold and reverse tear faulting perpendicular to the fold tip as visible on the seismic sections. A maximum uplift rate of 0.62 mm a−1 due to reverse thrusting of the Bellavista tear fault for the past 46 ka could have contributed to the overall uplift of the Bellavista terraces. Based on trigonometric relationships, a reverse fault slip rate of 0.86 mm a−1 and an age of 137 ka were calculated for this fault.In the eastern part of the Huallaga basin, a series of two fluvial terraces were formed with elevations of 13–15 m and 30 m + FP and with OSL ages of 6.9 ± 0.7 ka for T1 and 30.2 ± 3.1 ka for T2. The interpretation of a third new seismic profile crossing the study area in combination with field observations and trigonometric relationships shows that the terraces were formed by a complex system of oblique ramp and strike-slip faulting resulting in uplift and shortening rates of 1 mm a−1 and 1.96 mm a−1 between 30.2 ka and 6.9 ka respectively; and uplift and shortening rates of 2 mm a−1 and 3.70 mm a−1 from 6.9 ka until the present. Reverse slip of the Shapaja oblique ramp, that was responsible for uplift of the terraces, was calculated at 2.19 mm a−1 for the period 30.2 to 6.9 ka and 4.15 mm a−1 from 6.9 ka until the present. Measured total slip in combination with the calculated slip rates allowed an age calculation of 181 ka for the Shapaja thrust ramp. Our inferences showed that the studied tectonic structures absorb most of the present-day deformation in the Huallaga basin. The calculated uplift and shortening rates are compatible with published, present-day crustal movement velocities, and Miocene to present shortening rates for various, studied sites of the tropical Subandes and suggest that it is deforming at a relatively uniform rate.The timing of sedimentation of the terrace sediments may have corresponded to periods of increased precipitation which occurred coeval with the Heinrich events of the Northern Hemisphere. Terrace records similar as ours have been described for other, tectonically highly active areas in the tropical Subandes, but not in the tectonically less active Amazonian lowlands. It is suggested that uplift rates of at least 1 mm a−1 are needed to preserve suborbital climate cycles as individual terraces. The tropical Subandes could therefore be a new key area to investigate the interactions between tectonics, suborbital climate forcing and fluvial response during the late Quaternary.

Inviscid, Incompressible, Axisymmetric, Annular Jet Impingement

Abstract An analytical Bessel-sine series solution is presented for inviscid, incompressible, axisymmetric, annular impinging jets. The inflow velocity profile is relatable to an aircraft engine thrust reverser, and has a velocity deficit as well as nonzero vorticity function at the inner radius. As a consequence, inviscid recirculation appears at the impingement corner, the strength of which is made determinate by assuming a local patch of constant vorticity function. Results are first compared against prior round jet solutions, with rigorous convergence and accuracy assessment, before extension to annular impinging jets. Finally, while the Bessel-sine series are consistent with the governing equations and boundary conditions, computational issues arise with steep near wall gradients of a composite parameter that is inherent to the methodology, necessitating extremely fine mesh resolution. A hybrid of finite differences and Bessel series is proposed to address these numerical issues.

Analysis of the Orbital Approach Dynamics of the Space Debris Collector to the Fragment of Debris by the Method of Thrust Reversal with Interruption

The debris collector and a debris fragment move along random noncoplanar orbits in the altitude range of 400--2000 km. The thrust of the promising engine is 5000--25 000 N, the specific impulse of the promising fuel is not lower than 20 000 m/s. The remaining fuel after approach is not less than the specified. The debris collector undocks from the base station, transfers from its orbital plane to the debris fragment orbital plane, performs phasing, approaches the fragment, grabs it and returns to the base station. The paper considers only the stage of orbital approach. The duration of the entire flight mission is limited to one day. The phasing time is insufficient, therefore, at the start time of the orbital approach, the distance to the target is ~ 100 km, the relative velocity is ~ 1 km/s. On the other hand, for reliable and safe grabbing of a debris fragment, it is necessary to provide a distance of ~ 1 m and a relative velocity of ~ 1 m/s. It is shown that this can be achieved by approach using the method of thrust reversal with interruption. An effective algorithm of approach with target is proposed. An analysis of the orbital approach dynamics was performed by joint numerical integration of the orbital motion equations of the debris collector and the debris fragment by the 4th-order Runge --- Kutta method. Approach is performed in 6 cycles. In each cycle, the engine turns on three times. Two cycles are performed by sustainer engines, four cycles are performed by auxiliary engines of lower thrust. The fuel depletion and the non-sphericity of the Earth's gravitational field according to the 2nd zonal harmonic are taken into account. Calculation example is considered. Convergence estimates of the integration procedure by the resultant distance to the target and the resultant relative velocity are given. Resultant orbital approach is oscillation process with heavy damping. Damping is ensured by multiple firings of the sustainer (auxiliary) engine

Stability coordination control of multi-resource integrated microgrid considering demand response

Fully exploit the demand-side resources to build a multi-energy complementary microgrid system, which can improve the stability control of multiple indicators and save system operating costs. Based on the microgrid architecture including gas turbine generator set, energy storage system and central air-condition, each part of the system model is constructed to study the complementarity between resources, and a multi-resource integration multi-user regulation configuration method is proposed. Based on the principle of reverse thrust control, the multi-objective stability coordination control strategy of the microgrid system in off-grid mode is proposed, and the stability of the controller is proved theoretically. The control algorithm is verified by a simulation example. The result shows that the coordinated controller can ensure the tracking and adjustment of multiple controlled quantities such as power angle and frequency of the microgrid system during control, and the system can be quickly pulled back to stable operating state after the control is over. The participation of demand response resources in micro-network regulation can effectively improve the dynamic response of each state quantity of the system, and improve system stability, and reduce system control expenditure.

The 30 June 2017 North Sea Earthquake: Location, Characteristics, and Context

ABSTRACTThe Mw 4.5 southern Viking graben earthquake on 30 June 2017 was one of the largest seismic events in the Norwegian part of the North Sea during the last century. It was well recorded on surrounding broadband seismic stations at regional distances, and it generated high signal-to-noise ratio teleseismic P arrivals at up to 90° with good azimuthal coverage. Here, the teleseismic signals provide a unique opportunity to constrain the event hypocenter. Depth phases are visible globally and indicate a surface reflection in the P-wave coda some 4 s after the initial P arrival, giving a much better depth constraint than regional S-P time differences provide. Moment tensor inversion results in a reverse thrust faulting mechanism. The fit between synthetic and observed surface waves at regional distances is improved by including a sedimentary layer. Synthetic teleseismic waveforms generated based on the moment tensor solution, and a near-source 1D velocity model indicates a depth of 7 km. Correlation detectors using the S-wave coda from the main event were run on almost 30 yr of continuous multichannel seismic data searching for repeating signals. In addition to a magnitude 1.9 aftershock 33 min later, and a few magnitude ∼1 events in the following days, a magnitude 2.5 earthquake on 13 November 2016 was the only event found to match the 30 June 2017 event well. Using double-difference techniques, we find that the two largest events are located within 1 km of the main event. We present a Bayesloc probabilistic multiple event location including the 30 June event and all additional seismic events in the region well recorded on the regional networks. The Bayesloc relocation gave a more consistent seismicity pattern and moved several of the events more toward the west. The results of this study are also discussed within the regional seismotectonic frame of reference.