Lateral Wave Research Articles

Finding the mechanism of wave energy flux damping in solar pores using numerical simulations

Context. Solar magnetic pores are, due to their concentrated magnetic fields, suitable guides for magnetoacoustic waves. Recent observations have shown that propagating energy flux in pores is subject to strong damping with height; however, the reason is still unclear. Aims. We investigate possible damping mechanisms numerically to explain the observations. Methods. We performed 2D numerical magnetohydrodynamic (MHD) simulations, starting from an equilibrium model of a single pore inspired by the observed properties. Energy was inserted into the bottom of the domain via different vertical drivers with a period of 30 s. Simulations were performed with both ideal MHD and non-ideal effects. Results. While the analysis of the energy flux for ideal and non-ideal MHD simulations with a plane driver cannot reproduce the observed damping, the numerically predicted damping for a localized driver closely corresponds with the observations. The strong damping in simulations with localized driver was caused by two geometric effects, geometric spreading due to diverging field lines and lateral wave leakage.

ABOUT HEAD WAVES AND UNDER-SURFACE LONGITUDINAL WAVES, RADIATED BY THE NORMAL PROBE WHICH IS TAKING PLACE ON A FREE FLAT SURFACE OF THE ELASTIC ENVIRONMENT

On the basis of integrated representations Fourier–Bessel a component of displacement of elastic waves, radiating by the normal converter which is taking place on a free flat surface of the elastic environment, receives analytical estimations of displacement a under-surface longitudinal and head (it is surface-longitudinal) waves. Components of displacement a under-surface longitudinal wave are the sum a component in approximation of geometrical acoustics (GA), the diffraction amendments to this approximation and the amendments which are taking into account influence of feature when the parameter of integrated representation is equal to wave number of a longitudinal wave. Components of displacement of a head wave are defined as the sum appropriate diffraction amendments for a component of displacement of a volumetric longitudinal wave in approximation GA and a component of displacement of a lateral wave. The maximum of amplitude of displacement a under-surface longitudinal wave in angular area of a direction of distribution near to a free surface of environment is caused by one of local maxima of the directivity characteristic of the normal probe. Thus dependence of change of amplitude of this wave of distance wave from the centre of the probe practically corresponds to similar dependence for displacement of a volumetric longitudinal wave in GA approximation. Quantitative estimations of maxima of amplitude of displacement under-surface longitudinal and head waves concerning the greatest amplitude, radiated by the normal probe of a volumetric longitudinal wave.

Finite Range Integral Representation of Sommerfeld Integral for Homogeneous Dielectric Half-Space and Complete Uniform Asymptotic Expansion

Since the existing integral representations of the Sommerfeld integral (SI) are of the (semi) infinite type, a numerical error is inevitable due to the truncation of the integral range. In this article, a new finite range integral representation of the SI is formulated based on the exact image theory. To derive the new representation, a finite range integral expression of the exact image current is first derived. The radiated field by the exact image current is expressed in terms of a double integral in the complex domain where the exact image current flows. One of the two integrals is a semiinfinite line integral along the current path. This integral is deformed into a more convenient form as the exact image representation for the impedance plane. To convert the line source in the complex domain into a line source in the real domain, the path-deformation technique is again applied. The final line source consists of three line segments along which the exact image current flows vertically from the image source point to ±∞. In addition to the line source, a lateral wave component is also obtained. The impedance exact image representation can be evaluated as a closed-form expression in terms of an incomplete cylindrical function. Thus, the SI can be represented as the finite range integral of the incomplete cylindrical function. To efficiently evaluate the proposed integral, a complete uniform asymptotic expansion is formulated. All the proposed formulations are numerically verified, including, in some cases, near-Earth propagation, and their behaviors are investigated. Also, the electric field is computed for a vertical and horizontal infinitesimal dipole and compared by the exact Sommerfeld and known approximate formulations.

Erratum: Lamb Waves and Adaptive Beamforming for Aberration Correction in Medical Ultrasound Imaging.

In our paper titled "Lamb Waves and Adaptive Beamforming for Aberration Correction in Medical Ultrasound Imaging" [1], we mentioned that the superposition of the different symmetric (S) modes in the frequency-wavenumber (f-k) domain results in a high intensity region where its slope corresponds to the longitudinal wave speed in the slab. However, we have recently understood that this high intensity region belongs to the propagation of a wave called lateral wave or head wave [2-5]. It is generated if the longitudinal sound speed of the aberrator (i.e. the PVC slab) is larger than that of water and if the incident wavefront is curved. When the incidence angle at the interface between water and PVC is near the critical angle, the refracted wave in PVC re-radiates a small part of its energy into the fluid (i.e. the head wave). As discussed in [4], if the thickness of the waveguide is larger than the wavelength, the first arriving signal is the head wave. This is also the case in our study [1] where the ultrasound wavelength of a compressional wave in PVC was close to 1 mm, and a PVC slab with a thickness of 8 mm was used.

Numerical Analysis of the Seismic Response of Tunnel Composite Lining Structures across an Active Fault

The mechanical properties of high‐toughness engineering cementitious composites (ECC) were tested, and a damage constitutive model of the materials was constructed. A new aseismic composite structure was then built on the basis of this model by combining aseismic joints, damping layers, traditional reinforced concrete linings, and ECC linings. A series of 3D dynamic‐response numerical models considering the composite structure‐surrounding rock‐fault interaction were established to explore the seismic response characteristics and aseismic performance of the composite structures. The adaptability of the structures to the seismic intensity and direction was also discussed. Results showed that the ECC material displays excellent tensile and compressive toughness, with respective peak tensile and compressive strains of approximately 300‐ and 3‐fold greater than those of ordinary concrete at the same strength grade. The seismic response law of the new composite lining structure was similar to that of the conventional composite structure. The lining in the fault zone and adjacent area showed obvious acceleration amplification responses, and the stress and displacement responses were fairly large. The lining in the fault zone was the weak part of the composite structures. Compared with the conventional aseismic composite structure, the new composite lining structure effectively reduced the acceleration amplification and displacement responses in the fault area. The damage degree of the new composite structure was notably reduced and the damage area was smaller compared with those of the conventional composite structure; these findings demonstrate that the former shows better aseismic effects than the latter. The intensity and direction of seismic waves influenced the damage of the composite structures to some extent, and the applicability of the new composite structure to lateral seismic waves is significantly better than that to axial waves. More importantly, under the action of different seismic intensities and directions, the damage degree and distribution area of the new composite structure were significantly smaller than those of the conventional composite lining structure.

Glide-Symmetric Holey Structures Applied to Waveguide Technology: Design Considerations.

Recently, there has been an increased interest in exploring periodic structures with higher symmetry due to various possibilities of utilizing them in novel electromagnetic applications. The aim of this paper is to discuss design issues related to the implementation of holey glide-symmetric periodic structures in waveguide-based components. In particular, one can implement periodic structures with glide symmetry in one or two directions, which we differentiate as 1D and 2D glide symmetry, respectively. The key differences in the dispersion and bandgap properties of these two realizations are presented and design guidelines are indicated, with special care devoted to practical issues. Focusing on the design of gap waveguide-based components, we demonstrate using simulated and measured results that in practice it is often sufficient to use 1D glide symmetry, which is also simpler to mechanically realize, and if larger attenuation of lateral waves is needed, a diagonally directed 2D glide symmetric structure should be implemented. Finally, an analysis of realistic holes with conical endings is performed using a developed effective hole depth method, which combined with the presented analysis and results can serve as a valuable tool in the process of designing novel electrically-large waveguide-based components.

Study Recognizes and Assists in Mitigation of Bottomhole Assembly Lateral Vibration Chatter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 197231, “Recognition and Mitigation of the Bottomhole Assembly Lateral Vibration Chatter Mode,” by Jeffrey R. Bailey, SPE, and Harshit Lathi, ExxonMobil, and Matthew T. Prim, SPE, ADNOC, et al., prepared for the 2019 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 11-14 November. The paper has not been peer reviewed. Lateral vibration modeling of certain bottomhole assembly (BHA) designs has shown great sensitivity to the proximity of stabilizer blades. This paper explores the nature of the vibrational dysfunction known as BHA chatter. A field-proven frequency-domain model illustrates the cause of the dysfunction, its rotary-speed dependence, and mitigation methods and results. The complete paper provides three case studies exploring this phenomenon, one of which is included in this synopsis. Introduction The authors first describe the similarities and differences of a BHA and a stringed instrument. The string of a violin, for example, typically has two fixed nodal points: the first at the bridge, which does not change, and the second at the position of the musician’s finger, which is moved along the fingerboard in order to play notes of different frequencies. The finger pressing on the string causes it to have zero displacement at that location, which defines a nodal point. Additional nodal points may occur in the motion of the string as harmonics of the fundamental mode, but these are not considered to be fixed nodes because the amplitudes of the harmonics vary. The string is relatively flexible, so it can be described adequately with a second-order differential equation. Significantly, a BHA typically has more than two nodes. A lateral wave propagating along the BHA must satisfy the nodal point constraint of zero lateral deflection at all these locations. These nodes typically are placed without regard to the frequency of the wave traveling along the string, which is governed by the rotary speed and the type of lateral excitation. The geometric compatibility requirement that the pipe has zero displacement at the fixed nodes has ramifications. The nodal point constraints force the pipe to adapt to the locations of these nodes through contact forces that literally push the pipe back into position to honor the constraints. In some scenarios, this process requires large forces. One consequence of large forces pushing the pipe to maintain geometric compatibility is that these forces are applied to the outer diameter of a body that is rotating, so this response may also generate torque and associated wear of the contacting surfaces. This observation applies to both static and dynamic forces but most commonly is recognized in the static domain. It is not typically recognized in dynamics as applied to BHA design.

Positive effects of lateral rarefaction wave on the shock-wave-induced electromechanical coupling response of ferroelectric materials

Refinement design of shock-wave high-pressure loading is needed to suppress the lateral rarefaction wave, which can potentially reduce the pressure and inhibit the occurrence of pressure-induced effects (e.g. phase transition). In this study, based on the numerical simulation of shock dynamics, an ideal one-dimensional stress state in a ferroelectric crystal could be achieved in the lateral rarefaction zone under shock-wave loading. The thermodynamic analysis and experimental tests showed that, at the same loading rate, compared with one-dimensional strain state in the non-lateral rarefaction zone, one-dimensional stress in the lateral rarefaction zone was more conducive to the occurrence of electromechanical coupling effects, such as ferroelectric phase transition and depolarization, thus releasing more charges. It was also indicated that lateral rarefaction protection may not be always necessary in the shock compression experiments.

Source Image Squeezing and Field Tunneling for Propagating Light Beyond-Limit Focusing to Reach the Intermediate Zone

The physics for beyond-limit focusing has great academic importance, particularly for light propagation with control over focal point location and spot size. Asymmetric boundary confinement for a beyond-limit focusing lens in a metallic subwavelength structure redirects the surface current at the inner edges of the interface between an upstream double slit with width much smaller than the wavelength and a downstream slit with width close to one wavelength. This induces intense localized fields and tightly squeezes spatial distributions for the wave sources and corresponding images that are critical for focusing beyond the diffraction limit, as opposed to separated sources in super-oscillatory lenses and metalenses for optically large areas. This squeezing simultaneously increases the distance between source and image peaks and reduces their distribution widths one order less than the wavelength. The corresponding spatial spectrum alters to excite an inward-propagation wave mode with strong lateral wave momentum for focusing. The radiated inward propagation wave mode can be manipulated to help the focused field tunnel through the downstream slit, such that the focal point can reach the intermediate zone. Source and image radiation confirmed that focused field propagation had good agreement with simulation results. The proposed analytical Green’s method opens new physics applications for this fundamental focusing process, offering new opportunities to further reduce spot size and tailoring the focal length for important potential plasmonic applications.

Hydrodynamics study on rectangular porous breakwater with horizontal internal water channels

A novel concept of a hybrid floating breakwater-windbreak structure is proposed to shield vulnerable coastal regions from both extreme wave and wind loads in storms. A porous design was adopted for the breakwater part of the structure with the view to improving its hydrodynamic performance. The porosity was achieved by having horizontal internal water channels in the breakwater for free passage of water through the breakwater body. The wave response of such a floating structure is first investigated by analytical solution and then partially compared with laboratory model tests. A CFD analysis was performed to investigate the sidewall effects in the model tests. The horizontal wave forces and wave elevations in the vicinity of the floating breakwater with and without internal water channels were measured experimentally and compared so as to assess the effect of the water channels. The results show that the water channels help to reduce the lateral wave excitation force which is advantageous to breakwaters held in position by mooring dolphins/caissons. At the same time, the floating breakwater efficiency was maintained since the porosity did not increase in the wave transmission coefficient.

3,000톤급 및 9,000톤급 실습선의 파랑 표류력 특성에 관한 연구

In this study, numerical calculations were performed to analyze the characteristics of wave drift forces on the 3,000 and 9,000 ton class training ships that have been recently built and operated. The longitudinal wave drift force shows a large value in the areas ⋋/L= 1.0 and ⋋/L =1.5 in the case of the head and bow seas, and shows a relatively small value in the short wavelength. In the case of a short wavelength at an encounter angle of 30 degrees, which is a stern sea, a fairly large lateral wave drift force is acting. The difference in wave drift force between the two ships does not appear to be large. It can be seen that a larger wave drift moment value is acting on the passenger type vessel T/S B in the case of a short wavelength.

Verification and Evaluation of Lateral Wave Propagation in Marine Environment

Lateral wave plays an important role in electromagnetic (EM) wave propagation in layered conducting media. The full utilization of lateral wave in marine layered media may provide an innovative way of transmedia wireless communication. However, the existing approaches for solving lateral wave are tedious and complicated. In this letter, a simple model was presented to obtain lateral wave and other EM components in marine layered media. The model based on vector potential has simple process, definite physical meaning, and high accuracy. The theoretical computations were compared with the experimental data on sea. The good agreement of the two results verified the rationality and reliability of the model. In addition, the lateral wave near the sea surface was investigated theoretically and experimentally. The results show that lateral wave has a good performance of propagation from seawater to air. The present approach is more concise and the results can provide more physical insight compared to applying asymptotic expansion methods.

Approximate Transient Field for a Gaussian Pulse Generated by a Horizontal Electric Dipole in a Three-Layered Thin Anisotropic Medium

This letter aims to address the calculation of transient field associated with a horizontal electric dipole (HED) excited by a Gaussian pulse in a three-layered anisotropic medium. Approximate formulas applicable to the far transient fields are derived, and analyzed for the case of a thin dielectric layer (a dielectric slab). The resultant analytical formulas have the merit of offering unique insights about the characteristics of the transient field that includes lateral waves, and trapped surface waves. Furthermore, the transient field is further examined for its propagation characteristics, propagation distance, as well as its dependency on dielectric parameters. Finally, usefulness of the proposed formulas are demonstrated by using a microstrip antenna as an example.

Cyclic response of monopile-supported offshore wind turbines under wind and wave loading in sand

Monopiles are popular solutions as the foundation to support offshore wind turbines (OWTs), which suffer from various amplitudes of continuous lateral cyclic wind and wave loading. The accumulation of tilt and change of the natural frequency of OWTs under cyclic loading have become crucial issues for OWT design. Hence the monopile-tower-soil system was established at the small-scale level based on similarity laws with a suit of constant-amplitude and multi-amplitude tests in dense sand. Two sets of gear-driving assembly were successfully set up to achieve the application of cyclic loading to the model OWT. The amplitude and symmetry of cyclic loading were specified as three indicative regions according to those of real wind farms. On the basis of test results, the two-way loading was found to be the most hazardous situation and the preloading condition led to a high accumulation of tilt. The change of natural frequency was controlled by the load magnitude and tended to increase during cyclic loads, while a sharp decrease was observed when sand subsidence was generated. The post-cyclic lateral capacity seemed to be a slight increase compared with the static capacity. The relevant analyses based on test results can provide practical recommendations for OWT design.

A novel planar, broadband, high gain lateral wave antenna array for body scanning applications

Abstract Three-dimensional body scanning systems are increasingly used in sensitive public areas such as airports. By providing a high resolution image of a person from all sides, it is possible to detect potential metallic, ceramic and explosive threats. For these systems, it is essential to design broadband antennas with a fan beam, highly directional radiation in one plane and wide in the other plane, and characterized by phase center stability as a function of frequency. In this paper, the planar lateral wave antenna (LWA) array is proposed to achieve these radiation requirements. The LWA has two critical shortcomings: the flaring part and the dielectric matching layers (MLs), to operate over very broad frequency bands. In this work, these shortcomings are overcomed by forming a connected array of planar LWAs to improve broadband performance and by applying necessary perforations on the dense dielectric lens antenna to create different effective relative permittivity regions. An eight element connected and perforated LWA array is designed to operate in the 8–24 GHz frequency band. The drilled holes are proved to play a similar critical role of MLs in internal reflection suppression. The results emphasize all crucial demands for body scanning systems.

Impact of β-blocker therapy on right ventricular function in heart failure patients with reduced ejection fraction. A prospective evaluation.

Beta-blocker (β-blocker) therapy has been shown to improve mortality and reduce hospitalizations in patients with heart failure (HF) with reduced ejection fraction (HFrEF). Although the physiological action mechanisms of β-blockers are well described, their effects on right ventricular (RV) function have not been prospectively studied. This prospective study aimed to (a) evaluate whether β-blocker therapy impacts RV remodeling based on echo parameters and (b) determine the predictive echo factors of β-blocker therapy response. From September 2017 to September 2018, HF patients were prospectively enrolled using CIBIS criteria: Class II, III, or IV HF; left ventricular ejection fraction (LVEF) of ≤40%; hospitalized for HF within the previous 12months. Echo evaluation was performed before initiating β-blocker therapy and 3months after optimal dose adjustment. Based on previous studies, patients with (absolute) LVEF≥5% improvement were considered significant β-blocker therapy responders. Overall, 40 patients (pts) completed the study, characterized as follows by age: 70±10years; gender: 10 women; cardiomyopathy etiology: idiopathic in 24 and ischemic in 16; NYHA Class: II in 22 and III in 10; LVEF: 32±5%; and NTProBNP: 2665±2400pg/mL. The final population comprised 32 pts (79%), with eight (21%) excluded: two because of β-blocker therapy intolerance, one lost to follow-up, and five withdrew from the study. Under β-blocker therapy, several echo parameters significantly improved: LVEF from 31.7±9 to 40.5±9 (P<.0001); LV end-diastolic volume (EDV) from 154±54 to 143±45mL (P=.06); LV end-systolic volume (ESV) from 107±49 to 88±37mL (P=.0006); LV ES from 46±11 to 64±13mL (P=.008); LV end-diastolic diameter (EDD) from 57±9 to 54±6mm (P=.04); LV end-systolic diameter (ESD) from 48±10 to 44±7mm (P=.007); and right ventricular systolic pressure (RV SP) from 39±10 to 32±8mmHg (P=.0001). Significant modifications were observed in terms of RV echo parameters: right ventricular (RV) size decreased from 30±4 to 27±5mm (P=.03), while RV systolic function significantly improved based on tricuspid annular plane systolic excursion (TAPSE) (16.5±4 vs. 19±4mm; 0.0006); DTI-derived tricuspid lateral annular systolic velocity wave (S') (10±2 vs. 11.3±3cm/s; P=.03); and RIMP (Tei index) (0.5±0.1 vs 0.46±0.1; P=.04). RV 2D fractional area change (%) did not significantly differ despite a clear improvement tendency (35±6 vs. 37±4%; P=.1). No significant modifications were observed concerning LV diastolic parameters. Overall, β-blocker echo responders (n=23/32; 72%) exhibited the same left and right echo parameters. No echo variables predicted the β-blocker response. In HFrEF pts, β-blocker therapy significantly improves LV and RV systolic remodeling. Accordingly, β-blocker therapy could be applied as soon as possible in HFrEF patients with right ventricular dysfunction so as to limit RV remodeling.

Two-Dimensional Shear Wave Elastography of Normal Soft Tissue Organs in Adult Beagle Dogs; Interobserver Agreement and Sources of Variability.

Shear wave elastography (SWE) induces lateral shear wave through acoustic pulses of the transducer and evaluates tissue stiffness quantitatively. This study was performed to evaluate feasibility and reproducibility of two-dimensional shear wave elastography (2D SWE) for evaluation of tissue stiffness and to examine technical factors that affect shear wave speed (SWS) measurements in adult dogs. Nine healthy, 2 year-old, adult beagles with the median weight of 9.8 kg were included. In this prospective, experimental, exploratory study, 2D SWE (Aplio 600) from the liver, spleen, kidneys, pancreas, prostate, lymph nodes (submandibular, retropharyngeal, axillary, medial iliac, and inguinal), submandibular salivary gland, and thyroid was performed in anesthetized beagles. Color map was drawn and SWS of each SWE were measured as Young’s modulus (kPa) and shear wave velocity (m/s). The effect of measuring site, scan approach, depth, and anesthesia on SWE was assessed in abdominal organs by two observers independently. A total of 27 SWE examinations were performed in 12 organs by each observer. All SWS measurements were preformed successfully; however, SWE in the renal medulla could not be successfully conducted, and it was excluded from further analysis. Interobserver agreement of SWE was moderate to excellent in all organs, except for the left liver lobe at 10–15 mm depth with the intercostal scan. In the liver, there was no significant effect of the measuring site and scan approach on SWE. SWS of the liver and spleen tended to be higher with increasing the depth, but no significant difference. However, anesthesia significantly increased tissue stiffness in the spleen compared to awake dog regardless of the depth (P < 0.05). There was a significant difference in SWS according to the measuring site in the kidneys and pancreas (P < 0.001). 2D SWE was feasible and highly reproducible for the estimation of tissue stiffness in dogs. Measuring site and anesthesia are sources of variability affecting SWE in abdominal organs. Therefore, these factors should be considered during SWS measurement in 2D SWE. This study provides basic data for further studies on 2D SWE on pathological conditions that may increase tissue stiffness in dogs.

Hydrodynamics of a twisting slender swimmer

Sea snakes propel themselves by lateral deformation waves moving backwards along their bodies faster than they swim. In contrast to typical anguilliform swimmers, however, their swimming is characterized by exaggerated torsional waves that lead the lateral ones. The effect of torsional waves on hydrodynamic forces generated by an anguilliform swimmer is the subject matter of this study. The forces, and the power needed to sustain them, are found analytically using the framework of the slender (elongated) body theory. It is shown that combinations of torsional waves and angle of attack can generate both thrust and lift, whereas combinations of torsional and lateral waves can generate lift of the same magnitude as thrust. Generation of lift comes at a price of increasing tail amplitude, but otherwise carries practically no energetic penalty.

Design, assessment and evaluation of structural stabilization system for weather buoys using a moving foil

This paper proposes a novel, simple and high-efficient submerged structural stabilization system for a self-stabilizing buoy that provides a stable platform for oceanographic and meteorological sensors. The proposed stabilization system is a Seesaw-like Tuned Mass Damper (STMD) combined with a foil and is designed in a way to harvest the activation energy from incoming waves. A fixed rudder in the rear underside of the buoy, as well as physical properties of the buoy, help to keep its balance in yaw and roll directions while encountering lateral waves. Therefore, the orientational stabilization of the whole structure is achieved by controlling only the pitch deviation. The proposed model is then simulated in a marine dynamic analysis software. Two different shapes of a thin rod and a foil were proposed for the sliding mass (slider) of the STMD and their performances are investigated and compared to each other in two different modes of passive and active control. In the passive mode, different mass ratios were conducted for the thin rod-shaped slider (i.e., a ratio of the effective mass of the stabilizing system to that of the whole structure) and a mass ratio of 8% could suppress the pitch deviation up to 81.3% in the resonance condition. The same STMD system with a mass ratio of 2% suppresses the pitch deviation by only 7%. In the active mode, the STMD with a thin rod-shaped slider and a mass ratio of 8% exhibits only 49.1% suppression effect in a multiwave condition. However, by changing the shape of the slider to a foil while controlling its angle of attack (AOA) mechanically, the system with the mass ratios of 2% and 8% could suppress the pitch deviation of the buoy up to 69.4% and 79.1%, respectively.

Influence of viscous boundary layer on initiation zone structure of two-dimensional oblique detonation wave

The influence of the viscous boundary layer on the oblique detonation wave structure has been simulated and analyzed by solving the two-dimensional Navier–Stokes equations containing the hydrogen/air elementary reaction model. It is found that the effect of the viscous boundary layer can be neglected in the smooth transition initiation structure, but not in the abrupt transition initiation structure. The interaction of the lateral shock wave and the viscous boundary layer results in the formation of a high-temperature recirculation zone near the wall of the initiation zone, a novel structure that does not appear in inviscid formulations. Within this structure, the chemical reaction is triggered to occur in advance, eventually leading to the equilibrium initiation position relocating upstream compared with the inviscid case. Nevertheless, the viscous boundary layer has a limited impact on the main flow region downstream of the oblique detonation. The shock wave structures and pressure distributions at various Mach numbers are obtained computationally and analyzed in detail.