Plate Velocity Research Articles

Numerical modelling of the stress in the Pamir-Hindu Kush region

The current stress state of the Earth's crust in Central Asia depends entirely on the interaction of the Eurasian plate with the Indian and Arabian plates. Moreover, an essential role in this action is played by the subduction process in the Pamir-Hind Kush zone. In this region, deep earthquakes and anomalies in seismic velocities indicate subduction of the Indian Plate. To determine the effect of earthquakes on the stress state of the Earth's crust in Central Asia, we analyzed the hypocenters according to the available data over a hundred years. Taking the envelope of the hypocenters as the surface of the subducted indenter, we analyzed its penetration into the mantle. Instead of the pushing force of the indenter, the velocity of the Indian plate is taken into consideration. A model of the stresses is constructed on the equations of creeping motion of a viscous incompressible fluid. The stress variation in the Earth's crust and mantle was calculated as the stress difference before and after the earthquake. The mechanism of earthquakes is modelled by an introduction of equivalent volume forces in the equilibrium equations corresponding to a couple dipoles without a moment. The equations of creeping motion are numerically solved using boundary element methods. Numerical experiments with different physical model parameters for the Earth's crust and mantle were conducted. To introduce the negative buoyancy of the subducting plate, partial eclogitization of the rocks in the collision zone was assumed. As a result, a certain combination of stiffness and density was determined for the lithosphere and mantle, which explained the peculiarities of this region. The influence of crustal and mantle earthquakes in the Pamir-Hindu Kush region on the change in background stresses in Central Asia was analyzed which are not higher than 2–3%.

Analysis of Tectonic Plate Velocity Variations in the Sunda Strait Based on GPS Time-series Data

Indonesia is an earthquake-prone country located in the junction of four tectonic plates, namely the Indo-Australian, Eurasian, Philippine, and Pacific. The convergent boundary between tectonic plates is also called a subduction zone that can produce great earthquakes in the future. One of the subduction zones in Indonesia is the Sunda Strait subduction zone which predicted can release a M7.8 earthquake. Previous research stated that there is a change in tectonic plate velocity after an earthquake ruptured. It is likely that this could happen in the Sunda Strait area which has experienced several large earthquakes. In this study, we conducted research to find out the information on the tectonic plate velocity changes in the Sunda Strait. We used Global Positioning System (GPS) time-series data provided by Indonesia Geospatial Information Agency (BIG). The time series data is used to calculate the earthquake displacement, the changes in GPS velocity of before and after earthquake, and the changes in velocity of each time interval. Our results show that the horizontal displacement due to the earthquake at all GPS stations ranged from 3.34 mm to 7.36 mm in the north-south direction and -27.45 mm to 0.18 mm in the east-west direction. Furthermore, the result of the changes in GPS velocity before and after an earthquake ranged from 2.25 mm/year to 12.60 mm/year and 1.80 mm/year to 13.35 mm/year. The pattern of change in velocity is likely due to post-seismic deformation from the 2012 Indian Ocean earthquake, the 2016 Sumatra earthquake, and also other tectonic factors.

Episodic growth of felsic continents in the past 3.7 Ga.

Continents form the most accessible parts of Earth, but their complex compositions make their origin difficult to investigate. A novel approach based on a comprehensive compilation of samarium-neodymium isotopic compositions of detrital sedimentary rocks is here used to unravel continental growth through time. This record reveals that continents were as felsic as today in the past 3.7 Ga (billion years) and that their growth was not continuous but episodic. Reworking of preexisting crust was a ubiquitous process during most of Earth history, but at least six periods of continental growth can be identified every 500 to 700 Ma (million years) in the past 3.7 Ga. This recurrence could be accounted for by changes in tectonic plate velocities favoring periods of rapid subduction and enhanced production of juvenile felsic crust.

Predicting metallic armour performance when impacted by fragment-simulating projectiles – model review and assessment

Metallic targets impacted by blunt-nosed, fragment-simulating projectiles typically fail via shear plugging. A number of models exist in open literature to predict the onset of this failure mode, which can be used to determine the ballistic limit velocity, VBL, for a particular combination of projectile and target plate. A set of nine existing penetration models for blunt projectiles were identified and reviewed for their ability to predict the plugging-mode ballistic limit velocity of monolithic titanium alloy, aluminium alloy, and steel alloy plates impacted by blunt-nosed, fragment simulating projectiles. A database of more than 650 experimental ballistic limit measurements was used to evaluate the performance of the predictive models, covering a wide range of ordnance and sub-ordnance velocities, normal and oblique impact angles, and target plate thicknesses. The range of experimental data typically exceeded that for which the applied models were derived or previously validated. Nonetheless, it was found that all nine models could predict the experimental ballistic limit to within +/- 50% of the experimental measurement for more than 50% of the ballistic tests considered.

The Seismicity of Indonesia and Tectonic Implications

AbstractIndonesian seismicity provides important insights into the tectonics and hazards of a region that is, characterized by a remarkable diversity in faulting, including subduction, extension, thrusting, and strike‐slip faulting. We present a synthesis of Indonesian seismotectonics by documenting the distributions of hypocenters (≥M 4.6) and focal mechanisms (≥M 5.0) over ∼20 years, quantifying seismicity rates, and comparing observed seismicity trends with recent tectonic and tomography models. Of the 20,622 events ≥M 4.6 observed in the study region, ∼77% are shallow (≤70 km depth) and of magnitudes <M 5.0 (68%). Sixty one events ≥M 7.0 occurred, five of which exceeded M 8.0, including the 2004 Mw 9.1 Sumatra‐Andaman earthquake. Regionally, about ∼320 ≥ M 5.0 earthquakes occur per year, and rates decrease exponentially with increasing temperatures and pressures between 50 and 300 km. Seismicity rates increase in the Mantle Transition Zone (MTZ) likely due to viscous resistance at the 410, 520, and 660 km discontinuities. Intermediate and deep events (≥70 km depth) trace the Wadati‐Benioff zones of several subducting slabs exhibiting geometries consistent with recent tomography models. Seismicity extends to a maximum depth of 678 km. Oblique convergence, lithospheric age, ambient mantle temperatures, and plate velocity likely contribute to the non‐uniform depth distribution of intermediate and deep earthquakes. Shallow seismicity provides insight into how complex oblique convergence is accommodated near the surface, with primary sources including megathrusting, crustal faulting, and shallow intraslab faulting. All sources of shallow seismicity constitute significant seismic hazards.

Study on the similarity of elasticity and ideal plasticity response of thin plate under impact loading

For the impact similarity problem of the scaled model and the prototype usually have different materials with elastic and plastic properties, the differences of material properties and the coexistence of elastoplastic in different deformation stages will lead to the failure of the previous impact similarity theory. Based on the theory of the thin plate impact problem, the similarity law of impact response was derived by using the method of equation similarity analysis for the material with the linear elastic and ideal rigid-plastic properties. The basic equations of the thin plate structure, such as the energy conservation equation and the strain-displacement equation, were analyzed using equation similarity analysis methods, and the similarity scaling factor of the ideal elastic-plastic thin plate structure was derived. Based on the equation similarity analysis methods, a thickness compensation method that can simultaneously consider the similarity of elastic deformation and plastic deformation was proposed. For the impact similarity problem of the scaled model and the prototype using different ideal elastoplastic materials, this method can be used to calculate the geometric sizes and load conditions of the scaled model through the material properties when the response of the scaled model is similar to that of the prototype. Two finite element models of circular plate mass impact and circular plate velocity impact were established.The geometric sizes and load conditions of the scaled model were calculated through the thickness compensation method when the prototype uses aluminum alloy and the scaled model uses different materials such as steel, brass, etc. The applicability of the thickness compensation method was verified by the response of prototype and scaled model. The results show that the structural response of the scaled model obtained by the thickness compensation method can accurately predict the impact response of the prototype, even though the scale model and the scale model use different materials.

Propagation of a precursory detachment front along a seismogenic plate interface in a rate–state friction model of earthquake cycles

SUMMARYA numerical simulation of earthquake cycles at the subduction zone of a plate interface was conducted, using a rate- and state-dependent friction law, to examine aseismic sliding processes propagating into a locked plate interface. In the model, a reverse fault is assumed in a 2-D uniform elastic half-space, and relative plate motion is imposed with a constant velocity. Simulated earthquakes occur repeatedly at a shallower seismogenic plate interface with a velocity-weakening frictional property, while stable sliding occurs in the deeper part, in which a velocity-strengthening frictional property is assumed. During interseismic periods, deep stable sliding causes shear stress to concentrate at the deeper edge of the locked plate interface, and a partial drop in stress occurs, resulting in plate detachment. The resulting detachment front propagates upwards along the seismogenic plate interface until an earthquake occurs, causing aseismic sliding with a sliding velocity significantly lower than the imposed relative plate velocity. The propagation velocity of the detachment front is almost constant in each case, and it is proportional to the relative plate velocity and inversely proportional to the effective normal stress. Episodic events of increased slip velocity occur in the latter half of an interseismic period when the characteristic slip distance is small. Updip propagation of episodic slip is arrested by a low stress barrier, and episodic slips backpropagate downdip. During the final few years of the simulation cycle, the average sliding velocity is approximately inversely proportional to the time to occurrence for a large interplate earthquake.

Accuracy estimation of site coordinates derived from GNSS-observations by non-classical error theory of measurements

The velocities of tectonic plates derived from GNSS time series are regularly used as input data for geophysical models. However, as shown by numerous researches, the coordinates time series contain residual errors of a systematic nature, which can significantly affect the reliability of the obtained velocity estimates. This research shows that using non-classical error theory of measurement (NETM) for processing GNSS time series allows detecting the presence of weak, not removed from GNSS processing, sources of systematic errors. Based on the coordinate time series of selected permanent GNSS stations in Europe, we checked the empirical distributions of errors by the NETM on G. Jeffries' recommendations and on the principles of the theory of hypothesis tests according to Pearson's criterion. It is established that the obtained coordinates time series of GNSS-stations only partially confirm the hypothesis of their conformity to the normal Gaussian distribution law, and this may be the main reason for their unrepresentative classification. In the future, it is necessary to identify and take into account the causes of residual errors that distort the real distribution of the results of the GNSS time series.

A nonlinear characteristic line model of the detonation process of aluminized explosives

Aiming at the non-ideal properties of aluminized explosive, a local isentropic hypothesis of the expansion of aluminized explosive detonation product was proposed, and a nonlinear characteristic line model for aluminized explosive detonation was established, which provides a new theoretical analysis method for studying the non-isentropic flow and the expansion of detonation products. A lot of studies have shown that for micron aluminum powder, the reaction mainly occurs in the expansion zone of detonation products. The aluminum powder was treated as inert in the detonation reaction zone in the model. Considering the reaction rate of the aluminum powder is relatively slow, the expansion process of the detonation products of aluminized explosive was divided into finite time regions. The energy released from the reaction of aluminum powder has a relaxation effect on the state of the products. Based on the relaxation effect, it was assumed that the detonation products flow was approximately isentropic in each time region. Due to the reaction of aluminum powder, the entropy in each time region was different. Based on the theory of isentropic flow of ideal explosive and local isentropic hypothesis, the non-isentropic expansion process of the detonation products of aluminized explosives can be analyzed theoretically. To verify the correctness of the model, metal plate experiments were conducted. Experiments on aluminized explosives and LiF explosives with a particle diameter of 5μm and 50μm to drive 0.5 mm and 1 mm metal plates were designed. The velocity history of the metal plate was measured by a laser displacement interferometer, and then the reaction degree of aluminum powder in the detonation products was calculated from the experimental results. Combined with the nonlinear characteristic line model of the detonation products of aluminized explosives, the velocity of the metal plate driven by aluminized explosives was calculated theoretically. Compared with the experimental results, the non-isentropic model can well describe the contribution of the secondary reaction of aluminum powder to the work ability of explosives, which verifies the correctness of the model for aluminized explosives (micron aluminum powder).

Numerical studies on laser impact welding: Smooth particle hydrodynamics (SPH), Eulerian, and SPH-Lagrange

Smooth particle hydrodynamics (SPH) and Eulerian methods are widely used in the numerical simulation of laser impact welding (LIW). However, SPH method cannot directly apply pressure load generated by plasma and can only realize the loading effect of the plasma pressure load by presetting the shape and initial velocity of the flyer plate. However, the welding interface waveform and jet phenomenon produced by the Eulerian method due to the regular material mixing mode is not as clear as that by the SPH method. In addition, it cannot effectively show the central springback and cracking in the LIW. A new numerical simulation method for LIW, namely, smooth particle hydrodynamics and Lagrange coupling method (SPH-Lagrange). The idea is to couple the Lagrange grid and SPH particles on the flyer model, which can apply the impact load generated by the plasma on the upper surface of the flyer model; as a result, the loading conditions are in line with reality. The simulation results of local velocity, shear stress, equivalent plastic strain, and temperature state of the welding interface obtained by the SPH, Eulerian, and SPH-Lagrange methods were compared and studied. The interface waveforms obtained by different laser energies were compared with the simulation results of the SPH-Lagrange method. The numerical simulation calculations show that the SPH-Lagrange method is more consistent with the LIW experiment. Compared with other methods, SPH-Lagrange method is more suitable for the simulation of the LIW combination process and interface characteristics. Finally, the possible existence of melting phenomenon in LIW process was investigated using the SPH-Lagrange method.

Three-dimensional graphing representing six variables for speed and separation performance in liquid chromatography

The two variables, flow rate and column length, enable naive determination of the number of theoretical plates (N) in isocratic elution; this, in turn, enables the formation of a three-dimensional graph with N as the z-axis. An alternate three-dimensional graph with N as the z-axis can be drawn, then, with the alternate basal plane illustrating the pressure drop and hold-up time. In this article, the pressure drop and hold-up time are formulated so as to be represented unitarily in the former graph, because the flow rate and column length interact simultaneously as operational variables. This formulation manipulates both the pressure drop and the hold-up time as logarithmic axes, to evaluate the landscape. Also of use is the representation, in the same graph, of the height equivalent to a theoretical plate, as the fundamental property of the packing supports. For this purpose, the number of theoretical plates per unit length are here introduced as the sixth variable, instead of the height equivalent to a theoretical plate. Representing the six variables in three-dimensional graphs enables a clear understanding both of the separation condition optimization methods and the relation among variables for the speed and separation performance. The linear velocity, column length, N, velocity-length product, hold-up time, and number of theoretical plates per unit length, are here selected as the six elementary variables for the three-dimensional graphs; and, based on the packing supports of 2, 3, and 5-μm particle and monolithic columns. Finally, the usage of logarithmic three-dimensional graph is illustrated for understanding the speed and separation performance.

The influence of strain rate on the cavitation time and deformation of an underwater impulsively rectangular plate

The effect of strain rate on the cavitation time and elastoplastic deformation of steel rectangular plate subjected to underwater explosion load is analytically and numerically investigated in this study. At the cavitation time, the total pressure of the explosion is eliminated so that the cavitation time plays a significant role in the elastoplastic deformation of underwater explosive forming of plate. Taking into account the strain rate effect, the Cowper-Symond constitutive equation of mild steel is employed. Exact linear solution using the Eigen function and numerical linear and nonlinear solution using finite difference method (FDM) of dynamic response of impulsively plate is obtained. Implementing the linear work hardening, the stress, strain, displacement, and velocity in any steps of loading are calculated. The time of cavitation can be recognized in elastic or plastic regimes by applying the Cowper-Symond constitutive equation. Considering the strain rate influence, the effects of charge mass and standoff are investigated to occur of cavitation and time dependent deflection and velocity of a rectangular plate.

Transient TEHD Analysis of a Thrust Bearing Based on Two-Way Fluid-Solid-Thermal Interaction

Thrust bearing is a key component of hydroelectric generator and bears the axial load of the unit. During transient processes, such as start and stop of the unit, thrust bearing usually occurs wear phenomenon at pad surface, which affects the stable operation of the unit and reduces service life of the bearing. Based on two-way fluid-solid-thermal interaction, this paper did transient thermal-elastic-hydrodynamic (TEHD) analysis of a tilting pad thrust bearing under the pump mode. For the fluid region, the Reynolds equation and the viscosity-temperature equation are solved. For the solid region, transient heat conduction equation and basic thermal-elasticity equation are considered. The data transferred in the fluid-solid interface satisfy the fluid-solid-thermal interaction equation. The variation of the lubricant oil temperature, the oil film force, the pad surface inclination angle and axial velocity of pad and mirror plate are analysed, which provide theoretical basis for the design of bearing and the safe operation of the unit.

Moment Tensor Components with Their Corresponding Eigen Values and Eigen Vectors for Earthquakes Mw ≥ 6.0 in Northern and Southwestern of Pakistan

Self-generated earthquake catalogue of Mw≥6.0 upto 300 km depth was prepared for the inversion of six components of moment tensor. Seismotectonic map was drawn with seismicity distribution. The stress map of Pakistan was generated through CASMO which described by the Anderson model (1951). The maximum horizontal stress (SHmax) acting in the compressional zone generates reverse faulting (RF) causes to form the three distressing mountainous range called Karakorum, Hindukush and Himalayan i-e SHmaxSHmin. In eastern side of Pakistan, minimum horizontal stress (SHmin) acting in the extensional zone produced normal fault (NF) i-e SHmax SHmin. Focal mechanism was also drawn using source parameters of each event obtained by matlab codes. Stress tensor components were obtained using mathematical equations and out comes were written in the form of 3x3 matrix. All matrices have non trivial solutions and their solution sets were also evaluated in the form of eigen values and eigen vectors. Crustal thickness was displayed by thickness map. The maximum thickness of curst in northern Pakistan i-e 60-70 km whereas in southwestern region this varied from 20– 40 km all around. This variation due to plate motion intensity and velocity of Indian and Eurasian plate collision.

Numerical study on turbulent characteristics of wall jet in a quiescent environment over a plate in motion

The present article reports the numerical analysis of a two dimensional turbulent wall jet flow over a horizontal moving plate in a quiescent environment. The simulation is done using the low-Reynolds number turbulence model proposed by Yang and Shih [21]. The turbulent characteristics are observed for various velocity ratio of plate with respect to jet (Up ) from keeping Reynolds number at jet inlet to be constant at 15000. The Reynolds averaged Navier Stokes (RANS) equations are discretized using the finite volume method and solved in steady state condition. The pressure correction technique applied to couple the velocity and pressure terms is SIMPLEC (semi-implicit pressure linked equation-consistent). The variation of jet half-width and the decaying local maximum velocity (Umax ) for the bottom plate moving with high velocity (Up > 1) shows dominancy of plate motion over the jet stream in the flow field. The velocity contour diagram shows the velocity distribution in the flow field. The Reynolds stresses induced in the wall proximate regions are directly proportional to the relative motion of the flow field but the magnitude of Reynolds stress away from wall decreases by increasing the plate velocity. The plate motion significantly affects the turbulence characteristics and the flow field in the viscous laminar zone of the wall region.

Modelling of Flow Behaviour and Rheological Properties of M2 Steel in Semisolid State

The present study develops a model to investigate time dependent behaviours of M2 steel in semisolid state during step-change in shear rate. The Couette flow of the semisolid material between two parallel plates is considered. The flow field is presented by momentum conservation equation. The non-Newtoniun behaviour of the semisolid material is expressed by the Herschel-Bulkley model. The agglomeration and de-agglomeration phenomena of the suspended particles in semisolid state under shear are represented introducing a time dependent structural parameter. The proposed model fitted well with existing work in a wide range of shear rates and could predict the flow and apparent viscosity of semisolid M2 steel. Finally, the work involves prediction of the flow field, rate of strain and apparent viscosity of the semisolid material under transient condition. It is observed that the time dependent viscosity is highly non-linear during step-change in shear rate. It is noticed that the structural parameter decreases as the shear rate is increased. Whereas, the apparent viscosity decreases with increasing shear rate but shows an undulation and after that gradually rises to a higher steady value as the plate velocity decreases suddenly.

Lithosphere as a constant-velocity plate: Chasing a dynamical LAB in a homogeneous mantle material

While the lateral limits of tectonic plates are well mapped by seismicity, the bottom boundary of the lithosphere, the uppermost rigid layer of the Earth comprising both crust and shallow mantle, remains elusive. The lithosphere is usually viewed as consisting of cold, rigid, internally undeformed blocks that translate coherently. The base of the lithosphere, designated as the lithosphere-asthenosphere boundary (LAB), may thus be characterised by different physical fields: temperature, viscosity, strain rate and velocity. The LABs as defined by these different fields are investigated here using thermo-mechanical models of plate and upper mantle dynamics, either in a transient subduction or in a steady-state plate-driven set-up. Mantle material is modelled as homogeneous in composition with a viscosity that depends on temperature, pressure and strain rate. In such a system, the thermo-mechanical transition between lithosphere and asthenosphere occurs over a finite depth interval in temperature, strain rate and velocity. We propose that the most useful dynamical LAB is defined as the base of a “constant-velocity” plate (i.e. the material translating at constant horizontal velocity). The bottom part of this plate deforms at strain rates comparable to those in the underlying asthenosphere mantle: the translating block is not fully rigid. Thermal structure exerts a major control on this dynamical LAB, which deepens with increasing plate age. However, the surface plate velocity, the asthenospheric flow geometry and magnitude also influence the depth of the dynamical LAB, as well as the thickness of the deformed region at the base of the constant-velocity plate. The mechanical transitions from lithosphere to asthenosphere adjust when mantle dynamics evolves. The dynamical and thermo-mechanical LABs occur within a thermal lithosphere-asthenophere gradual transition, similar to the one imaged by geophysical proxies. The concept of a constant-velocity plate can be extended to a constant-velocity subducting slab, which also deforms at its borders and drags the surrounding mantle. This framework is relevant to quantify mass transport within the Earth's mantle.

A Study of Human Balance and Coordination Using a Head Mounted Display

Abstract This paper reports on an experiment in human subject balance and coordination using a HTC Vive head mounted display to create a virtual environment. For the experiment, 30 male human subjects of college age and 30 female subjects of college age were asked to navigate along a clear path in a virtual world using a controller with their dominant hand and asked to balance a virtual ball on a virtual plate using the other controller in the non-dominant hand. The test subjects moved along a clearly marked path, with three surprise obstacles occurring: a large rock landing near the path, and explosion near the path, and a flock of birds coming across the path. Data included 6 degree of freedom trajectories for the head, and both hands, as well as data gathered by the computer system on ball location and velocity, plate location and velocity and ball status. Likert scale questionnaires were answered by the test subjects relative to video game experience, sense of presence, and ease of managing the ball movement. Statistics showed that the male students dropped the ball less frequently at p = 0.0254 and p = 0.0036. In contrast, female students were aware of their performance with correlation levels of 0.632 and 0.588.

Thermo‐Mechanical Numerical Modeling of the South American Subduction Zone: A Multi‐Parametric Investigation

AbstractThe South American subduction zone is enigmatic due to its fast subducting plate consumption, strong oscillation in subducting plate velocity, and deep mantle subduction. A key to help understand these subduction zone characteristics is through studying its dynamics with buoyancy‐driven numerical modeling that uses independent variables to best approximate the dynamics of the real subduction system. We conduct a parametric investigation on the effect of upper mantle rheology, subduction interface yield stress and slab thermal weakening. To constrain those model variables, we attempt to find best‐fits by comparing our model outcomes with the present‐day slab geometry and estimates of Cenozoic velocities in the center of the South American subduction zone. Key ingredients that need to be reproduced are low slab dip angles close to the surface, steeper lower mantle dip angles, strong oscillation of the fast Farallon‐Nazca subducting plate velocity and a progressive decrease in trench retreat rate during long‐term subduction. We include these ingredients to define a model fitting score using 10 criteria. Our best fitting models involve a weak subduction zone interface (yield stress of ∼20 MPa) and significant slab thermal weakening to attain the fast Farallon‐Nazca subducting plate velocity and to better reproduce the subduction partitioning since 48 Ma due to reduced shear stresses resisting downdip slab sinking and reduced slab bending resistance. Furthermore, a non‐Newtonian upper mantle promotes slab folding and realistic oscillation of the subducting plate velocity. Whether and how this slab folding process induces temporal variations in Andean deformation remains an open question.

Investigation of interaction between thermodynamic processes and pressure pulsation based on transient CFD model of a reciprocating compressor

This paper presents a transient computational fluid dynamics (CFD) model of a reciprocating compressor to study the interaction of the thermodynamic process and pressure pulsation. To realize the interaction between the thermodynamics and the pressure pulsation, the most difficult procedure lies in dealing with the valve motion and flow through the valve channel both precisely and effectively. Therefore, a discretization method for the flow channel of the ring valve to generate structured grids is proposed. Then, the subsequent model is embedded in the flow channel of the compressor model. User-defined functions are employed to calculate the independent velocity of each valve plate based on the real-time pressure differences across the valve plates. After verified, the influences of the discharge pipeline configuration, pressure ratio, and rotational speed were examined. The results of the numerical model agreed well with the experiment. The maximal deviation between predictions and experiments at the pressure ratio of 3 was 6.14% of indicated power. The maximum deviation increased to 7.42% at the rotational speed of 480 rpm. The results for the discharge pipeline configuration verified that the buffer tank directly following the nozzle of the compressor contributed greatly to attenuating the pressure pulsation. A fast Fourier transform analysis of pressure pulsation showed that at all speeds, the amplitudes were almost the same below the eighth harmonic, and then gradually increased for the higher harmonics.