Terms Of Velocity Research Articles

Experimental investigation of hail impacts over a wide range of high velocities

In the presented work, high velocity hail impact tests have been conducted on an instrumented rigid target. The synthetic hails, consisting of ice spheres with a nominal diameter of 48 mm and a mass between 50 and 55 g conditioned to temperatures in the range of -3, -20 and -50 °C were accelerated using a gas gun. The range of impact velocities was 46–314 m/s leading to maximal impact energies between 2000 and 3000 J which had not been investigated so far in the literature. Peak force and time to reach the peak force where extracted from the experimental tests. The obtained results were compared with results from the literature using empirical equations established in another publication from the literature. The obtained results confirm the trend reported in the literature in terms of dimensionless peak force versus dimensionless impact velocity. However, the dimensionless time to reach the peak force during the impact could not be compared successfully with previous results. The role of the target characteristics is estimated to be the reason for this difference.

Free-Surface Vortices Mitigation using Anti-Vortex Plates in Dam Intakes through CFD

By recording parameters such as velocity and volume fraction by contour plots or plane, a CFD model enables to analyse flow patterns in the model, such as free-surface vortices A free-surface vortex, a common problem may indeed be observed in a variety of submerged water intakes, notably shallow basins and low head intakes. These FSVs are likely to form an air-core vortex, eventually entrapping detritus and air pockets in the water intake system and causing further vibration and damage to the downstream turbine. When paired with a high velocity, the formation of vortices in the system been known to produce hydraulic transients, which cause unwanted operation or pressure changes. The model of the 1:100 scale dam reservoir was generated, computationally meshed, and modelled in FLUENT under ANSYS 2019 R3 at two different water levels to observe the FSV formations. To mitigate those FSV formations, anti-vortex plates with two distinct plates—square and wedge—were used. From the findings square plates outperform wedge plates because square it lowers the speed of a fast-flowing fluid and reduces it into a laminar flow rather of a turbulent flow, which benefits vortex class deterioration. Data from the simulation and experimental shows a strong agreement in terms of velocity at outlet 1 from both water levels with relative errors of 3.0% and 14.1% respectively

A robust and contact resolving Riemann solver for the two-dimensional ideal magnetohydrodynamics equations

This paper presents a new cell-centered numerical method for ideal magnetohydrodynamics (MHD) that can be used in Lagrangian or Eulerian discretization. A two-dimensional Riemann solver based on the HLLC-type MHD method is established, which can be viewed as an extension from the HLLC-2D in hydrodynamics. The main feature of the algorithm is to introduce a nodal contact velocity and ensure the compatibility between edge fluxes and the nodal flow intrinsically. It transforms naturally from Lagrangian setting to the Eulerian setting in terms of grid nodal velocity, and gains benefits of the Lagrangian nature of the scheme. In the Lagrangian approach, the finite volume scheme itself can keep the magnetic field divergence-free strictly, while in the Eulerian case, a special constrained transport (CT) algorithm is constructed from the discontinuous fluxes on cell interfaces to ensure solenoidal nature again. Numerical tests are presented to demonstrate the performance of this new solver and compare the difference between the Lagrangian and Eulerian methods.

Ballistic response of skin simulant against fragment simulating projectiles

The response of biological phantoms against high velocity impact is actively sought for applications in defense, space, soft robotics and sensing. Towards this end, we study the ballistic response of silicone based skin simulant against fragment impact. Using a pneumatic gas gun setup, six chisel-nosed and three regular shaped (sphere, cylinder, and cube) fragments were impacted on the skin simulant. The resulting skin simulant response was studied in terms of ballistic limit velocities, energy densities, failure pattern, and the mechanics of interaction. The results indicate that the shape of the fragment affects the ballistic limit velocities. The ballistic limit velocities, energy densities of the chisel-nosed fragment simulating projectiles were relatively insensitive to the size (mass), except for the smallest (0.16 g) and largest (2.79 g) chisel-nosed fragment. For the same size (1 g), ballistic limit velocities and failure are dependent on the shape of the fragment. The skin simulant failed by combined plugging and elastic hole enlargement. Failure in the spherical fragment was dominated by the elastic hole enlargement, whereas plugging failure was dominant in all other fragments. The spherical, cylindrical, and chisel-nosed fragments created circular cavities, and the cubical fragment created a square cavity. In the case of the spherical fragment, slipping of the fragment within the skin simulant was seen. Cubical fragments created lateral cracks emanating from the corners of the square cavity. Interestingly, for all the fragments, the maximum deformation corresponding to the perforation was lower than the non-perforation indicating rate dependent, stress driven failure. The maximum deformation was also dependent on the shape of the fragment. Overall, these results provide unique insights into the mechanical response of a soft simulant against ballistic impact. Results have utility in the calibration and validation of computational models, design of personal protective equipment, and antipersonnel systems.

A compressible multi-scale model to simulate cavitating flows

We propose a compressible multi-scale model that (i) captures the dynamics of both large vapour cavities (resolved vapour) and micro-bubbles (unresolved vapour), and (ii) accounts for medium compressibility. The vapour mass, momentum and energy in the compressible homogeneous mixture equations are explicitly decomposed into constituent resolved and unresolved components that are independently treated. The homogeneous mixture of liquid and resolved vapour is tracked as a continuum in an Eulerian sense. The unresolved vapour terms are expressed in terms of subgrid bubble velocities and radii that are tracked in a Lagrangian sense using a novel ‘ $kR$ - $RP$ equation’ (k, constant multiple; R, bubble size; RP, Rayleigh-Plesset). The $kR$ - $RP$ equation is formally derived in terms of the pressure at a finite distance ( $kR$ ) from the bubble while accounting for the effects of neighbouring bubbles; $p(kR)$ may therefore be either a near-field or far-field pressure. The equation exactly recovers the classical Rayleigh–Plesset and Keller–Miksis equations in the limits that $k$ and $c$ (speed of sound) become very large. Also, the results are independent of $k$ for a single bubble for all $k$ , and for multiple bubbles when $kR < d$ (where $d$ denotes separation distance). Numerical results show this robustness of the model to the choice of $k$ , which can be different for each bubble. The multi-scale model is validated for the collapse of a single resolved/unresolved bubble. Its ability to capture inter-bubble interactions is demonstrated for multiple bubbles exposed to an acoustic pulse. The model is then applied to a problem where resolved and unresolved bubbles co-exist. Finally, it is validated using a cluster of $1200$ bubbles exposed to a strong acoustic pulse. The results show the impact of the bubble cluster on the transmitted and reflected waves and the shielding effect where bubbles at the edge of the cluster shield the interior bubbles by dampening the incident acoustic wave.

Numerical investigation of the effects of symmetric and eccentric earthquake-induced pounding on accelerations and response spectra for two-storey structures

This paper examines the effect of symmetric and eccentric earthquake-induced pounding between adjacent two-storey structures on acceleration times histories and response spectra. The numerical investigation benefits from experimental data issued from an extensive shake table campaign involving two-storey steel–concrete composite structures and slab-to-slab contacts. It is shown that the high frequency branch of the floor response spectra is only related to the maximum impulse acceleration spike during time, characterized by its impulse value, contact duration and time-history shape. In order to numerically reproduce such characteristics, three-dimensional detailed models are set up by modeling the slab with shell elements or hexahedral elements. Previously developed explicit time integrator, the CD-Lagrange scheme, based on non-smooth contact dynamics approach, is employed for ensuring the contact conditions expressed in terms of velocity and impulse, without requiring any contact parameters such as contact stiffness, local damping and restitution coefficient. The eccentric pounding between slabs is simulated by introducing a small defect in the parallelism of the colliding slabs, as measured in experience. The results of eccentric and symmetric pounding, assuming elastic behavior for the steel and concrete materials, are compared with the experimental data in terms of acceleration time-histories and pseudo-acceleration response spectra. It is concluded that symmetric pounding predicts an acceleration spike with a more abrupt increase to the peak and a shorter contact duration in comparison to experimental data, leading to an overestimation of the high frequency branch of the response spectra. On the contrary, eccentric pounding achieves to reproduce the experimental acceleration time histories as well as response spectra up to 400 Hz. Finally, the robustness of the proposed numerical approach is underlined by changing the time step size of the CD-Lagrange scheme as well as by prospecting different relevant choices concerning the Rayleigh damping.

Fiber trajectory tracking of centrifugal spinning and coupled-forces field effects on jet motion stability

High-speed centrifugal spinning holds excellent potential as a promising approach for nanofiber manufacturing due to its various raw materials, low environmental requirements, and high preparation efficiency. However, continuous jet movement and trajectory tracking on the action of gravity, centrifugal force, Coriolis force, viscous force, and air resistance remain significant challenges. Therefore, the present article has developed a polymer jet motion model based on the momentum equation, continuity equation, and constitutive equation of non-Newtonian fluid to explore the influence of spinning parameters on jet motion. Moreover, curved fiber trajectory in the centrifugal field, jet velocity distribution, and variation of air velocity around the nozzle have been simulated using the discrete phase model in terms of different angular velocities and solution concentrations. It is found that the angular velocity affects the formation of the jet trajectory. Furthermore, the solution concentration determines the attenuation of the jet velocity. Therefore, centrifugal spinning experiments have been carried out to verify the correctness of the results and theoretical analysis gained from the research. Scanning electron microscope observations show nanofibers with 6 wt% polyethylene oxide solution at 5500 rpm have better morphology and quality.

Highly energetic rockfalls: back analysis of the 2015 event from the Mel de la Niva, Switzerland

Process-based rockfall simulation models attempt to better emulate rockfall dynamics to different degrees. As no model is perfect, their development is often accompanied and validated by the valuable collection of rockfall databases covering a range of site geometries, rock masses, velocities, and related energies that the models are designed for. Additionally, such rockfall data can serve as a base for assessing the model’s sensitivity to different parameters, evaluating their predictability and helping calibrate the model’s parameters from back calculation and analyses. As the involved rock volumes/masses increase, the complexity of conducting field-test experiments to build up rockfall databases increases to a point where such experiments become impracticable. To the author’s knowledge, none have reconstructed rockfall data in 3D from real events involving block fragments of approximately 500 metric tons. A back analysis of the 2015 Mel de la Niva rockfall event is performed in this paper, contributing to a novel documentation in terms of kinetic energy values, bounce heights, velocities, and 3D lateral deviations of these rare events involving block fragments of approximately 200 m3. Rockfall simulations are then performed on a “per-impact” basis to illustrate how the reconstructed data from the site can be used to validate results from simulation models.

Dynamic stability analysis of metro tunnel in layered weathered sandstone

In this study a coupled-eulerian–lagrangian (CEL) approach has been applied to assess the internal blast loading conditions, for the tunnel built in three layers of sandstone rock. The three weathered stages of sandstone have been considered in this study i.e., slightly, medium and also highly weathered sandstone in three different layers. The sandstone rock weathering increases as we move towards the ground surface from deep subsurface. The elastoplastic finite element model with varied overburden depth with dimensions of 60 m (L × B × H) each to incorporate different parametric cases. An explosive is assumed at the center of the tunnel, with the capacity of hundred kg of trinitrotoluene (TNT), the explosive is assumed to be hanging in the air inside the tunnel opening with equal distance from all sides. The TNT sphere and air that is inside the rock tunnel has been modelled through CEL technique to simulate actual in-situ condition. Through Mohr-Coulomb, Concrete Damage Plasticity, and Johnson-Cook constructive material model the elastoplastic behaviour of different materials like rock, steel bars and concrete has been simulated respectively. The cage of steel bars has been embedded through interaction constraint in concrete liner to produce reinforced concrete liner. In the initial stages of simulation with 5 m of overburden depth the tunnel has been placed in the upper layer of sandstone. For further analysis, the position of the tunnel has been changed for overburden depth of fifteen, twenty-five and thirty-five meter. In accordance with the result of the simulation, for rock in terms of acceleration, velocity, and dis-placement, the depth of the overburden and the displacement of the crown are inversely related. No damage in terms of compression is seen in this simulation, but in all instances, a small damage owing to tensile failure has been noted.

Lattice Boltzmann Method Pore-scale simulation of fluid flow and heat transfer in porous media: Effect of size and arrangement of obstacles into a channel

The flow characteristics at a pore-scale porous medium has a significant role to the development of cooling modules. Despite this fact, still there is no adequate knowledge about the effect of size, pattern and position of the obstacles, on fluid flow and heat transfer. In this work, fluid flow through the porous media and heat transfer have been modeled by means of the Single Relaxation Time SRT-LBM with BGK approximation and D2Q9 model. The effect of size and arrangement of cold square obstacles in a heated wall channel is investigated for incompressible flow in case of fixed porosity degree, ε=75%. Results are presented in terms of velocity and temperature fields, streamlines, and Nusselt number. The results show that, for the same porosity degree, by changing the number of the obstacles or their arrangement, the tortuosity changes and therefore velocity and temperature fields are modified, as well as local and average Nusselt number. The results show that, for the same porosity degree, by changing the number of the obstacles or their arrangements, the value of Nuavg of the channel walls and tortuosity increased up to 24.7% and 9%, respectively, in comparison with the Poiseuille flow.

Effects of stance control via hidden Markov model-based gait phase detection on healthy users of an active hip-knee exoskeleton.

Introduction: In the past years, robotic lower-limb exoskeletons have become a powerful tool to help clinicians improve the rehabilitation process of patients who have suffered from neurological disorders, such as stroke, by applying intensive and repetitive training. However, active subject participation is considered to be an important feature to promote neuroplasticity during gait training. To this end, the present study presents the performance assessment of the AGoRA exoskeleton, a stance-controlled wearable device designed to assist overground walking by unilaterally actuating the knee and hip joints. Methods: The exoskeleton's control approach relies on an admittance controller, that varies the system impedance according to the gait phase detected through an adaptive method based on a hidden Markov model. This strategy seeks to comply with the assistance-as-needed rationale, i.e., an assistive device should only intervene when the patient is in need by applying Human-Robot interaction (HRI). As a proof of concept of such a control strategy, a pilot study comparing three experimental conditions (i.e., unassisted, transparent mode, and stance control mode) was carried out to evaluate the exoskeleton's short-term effects on the overground gait pattern of healthy subjects. Gait spatiotemporal parameters and lower-limb kinematics were captured using a 3D-motion analysis system Vicon during the walking trials. Results and Discussion: By having found only significant differences between the actuated conditions and the unassisted condition in terms of gait velocity (ρ = 0.048) and knee flexion (ρ ≤ 0.001), the performance of the AGoRA exoskeleton seems to be comparable to those identified in previous studies found in the literature. This outcome also suggests that future efforts should focus on the improvement of the fastening system in pursuit of kinematic compatibility and enhanced compliance.

An Analysis of The Material and Design of an Exhaust Manifold for A Single-Cylinder Internal Combustion Engine

This study aims to find the best material for the manifold and improve airflow in the UniMAP Automotive Racing Team (uniART) exhaust manifold. The exhaust manifold is a part of the exhaust system that collects and delivers exhaust gases from the cylinder head to the exhaust outlet. The exhaust manifold’s design is significant to the engine performance. The current design and new designs of the exhaust manifold were modelled using SOLIDWORKS software. Stainless steel, cast iron and mild steel were chosen as materials for manifold and were studied by conducting the Steady-State Thermal analysis. The flow of the air in the manifold is analysed and evaluated in terms of pressure and velocity. The fluid flow and thermal analysis are simulated in Computational Fluid Dynamics analysis software known as ANSYS. Results of thermal analysis prove that Stainless steel is better than other materials since it has a high temperature difference and low heat flux. The results of fluid flow analysis were compared between the current design and new designs of the exhaust manifold. The outcome indicated that validated Design 2 has a higher velocity value at the outlet and lower pressure at inlets which improves the airflow in the exhaust manifold.

Atnalı böbrekte nutcracker sendromu beklenen bir vasküler anomali midir?

Purpose: Horseshoe kidney is the most common fusion anomaly that congenital systemic and urological anomalies accompany most of the patients. In this study, we aimed to investigate its association with vascular anomalies and especially nutcracker syndrome along with accompanying urological and other systemic anomalies in children with horseshoe kidney. 
 Materials and methods: Twenty-six patients are diagnosed with horseshoe kidney in our clinic and 22 healthy children of the same age and sex were included in the study. All children were prospectively evaluated using Doppler ultrasonography in terms of renal artery and renal vein flow velocities, lumen diameters and vascular anomalies and presence of nutcracker syndrome. 
 Results: Urological anomaly was found in 50% of the children with horseshoe kidneys, and systemic anomaly in 44% of them. In Doppler ultrasonographic evaluations performed on patients to detect vascular pathologies and nutcracker syndrome; findings of nutcracker syndrome were present in 2 patients in the horseshoe kidney group, while they were detected incidentally in 1 patient in the control group. An accessory renal artery originating from the left common iliac artery was found in a case with horseshoe kidney, and a circumaortic left renal vein in one case. 
 Conclusions: In our study in which we investigated nutcracker syndrome based on the presence of vascular anomalies accompanying horseshoe kidneys in children, nutcracker syndrome findings were found in similar numbers in both groups. However, we think that these children should be followed for a long time in terms of vascular pathologies (aneurysm, rupture) and malignancies that may occur in adulthood, as well as congenital vascular anomalies.

Physical and Mechanical Behaviors of Compacted Soils under Hydraulic Loading of Wetting–Drying Cycles

Exposed geo−infrastructures filled with compacted soils experience cyclic wetting–drying effects due to environment and underground water fluctuations. Soil physical and mechanical behaviors are prone to deterioration to a great extent, e.g., swelling, collapse, or even slope failure, resulting in huge losses to human life, safety, and engineering construction. In this paper, hydraulic loading tests of wetting–drying cycles were carried out on compacted fine soil via a one−dimensional pressure plate apparatus equipped with bender elements. The influences of wetting–drying paths on the soil characteristics of moisture content, void ratio and shear modulus were obtained and analyzed. Results showed that cyclic wetting–drying effects weakened the soil’s water retention capacity. It was observed that it was harder for pore water to approach saturation at a lower matric suction level and to be expelled at a higher matric suction level. Typical swelling and shrinkage deformations occurred during the hydraulic loading processes, and volume expansion was generated after the drying–wetting cycles at a given value of matric suction, which deteriorated the densely compacted soils to a relatively looser state. Then, a unified soil–water characteristic surface was proposed to describe the unique relationships of moisture content, void ratio, and matric suction. Moreover, the small−strain shear modulus of the soil, in terms of shear wave velocity, was reduced by 32.2–35.5% and 13.8–25.8% at the same degree of saturation during the first and second wetting paths, respectively. Therefore, the volume expansion and modulus degradation resulting from the wetting–drying cycles should attract particular attention to avoid further distresses in the practical engineering.

Ballistic response of sandwich shell panels: A comparative study

The present work was carried out to explore the impact response of hemispherical (HSS), cylindrical (CSS) and flat sandwich structures (FSS) subjected to high-velocity impact through experimental and numerical simulations. All three-sandwich structures comprised of Al 1100-H12 face skins and Al -3003 H12 honeycomb core. For the direct comparison, the radius and thickness of all three-sandwich structures were kept identical. The high velocity impact tests were performed by using a pneumatic air gun. The hemispherical and conical shape projectiles were impacted typically at the centre (axis) of the sandwich structures with varying impact velocity. The finite element simulations were carried out through commercially available software Abaqus/explicit. The numerically obtained test results were validated through the experimental results to check the accuracy of the modelling. The response of all three structures was examined by comparing their ballistic resistance, failure mechanics and energy absorption characteristics. In addition, the parametric study was conducted numerically by changing the face skin thickness, cell length and cell wall thickness to find out their influence on the impact response of all three structures. The results revealed that the hemispherical structures showed higher impact resistance in terms of higher ballistic limit velocity and energy absorption. The ballistic limit of the HSS structure was 14.6% and 36.5% higher than the CSS and FSS structure respectively against hemispherical nosed projectile whereas the corresponding value against conical projectile was 9.9% and 20.6% respectively.

A novel model of gravity challenge device

Gravity is omnipresent force on the Earth and all living things have evolved under the constant influence of gravity. Some organisms learned to take advantage of this force by using it as a reference in their motion. On the other hand, many studies in living organisms shown that microgravity has a significant effect not only on the systemic level but also on the cellular level. In this study, a new model has been designed for a device that simulates microgravity in outer space. The model is made of acrylic with precise geometric dimensions with capabilities of controlling it in terms of angular velocities for the outer and inner frames, the distance of the sample from the center of rotation, and the time of reversal of the direction of rotation which produces smooth geometric path of the gravity vector of the biological sample. Besides, the designed algorithm has the ability to display the average gravity value of the coordinates (x, y, z) and the total value of the average gravity (G total) in the form of a curved figure in an instantaneous manner. Moreover, this design contributes to reducing the effort and cost of conducting biological studies on living organisms in space and opening new horizons for sciences that deal with the effect of microgravity on living organisms.

A Velocity-Based Approach to Noninvasive Methodology for Urodynamic Analysis.

To date, invasive urodynamic investigations have been used to define most terms and conditions relating to lower urinary tract symptoms. This invasiveness is almost totally due to the urethral catheter. In order to remove this source of discomfort for patients, the present study investigated a noninvasive methodology able to provide diagnostic information on bladder outlet obstruction or detrusor underactivity without any contact with the human body. The proposed approach is based on simultaneous measurements of flow rate and jet exit velocity. In particular, the jet exit kinetic energy appears to be strongly related to bladder pressure, providing useful information on the lower urinary tract functionality. We developed a new experimental apparatus to simulate the male lower urinary tract, thus allowing extensive laboratory activities. A large amount of data was collected regarding different functional statuses. Experimental results were compared successfully with data in the literature in terms of peak flow rate and jet exit velocity. A new diagram based on the kinetic energy of the exit jet is proposed herein. Using the same notation as a Schäfer diagram, it is possible to perform noninvasive urodynamic studies. A new noninvasive approach based on the measurement of jet exit kinetic energy has been proposed to replace current invasive urodynamic studies. A preliminary assessment of this approach was carried out in healthy men, with a specificity of 91.5%. An additional comparison using a small sample of available pressure-flow studies also confirmed the validity of the proposed approach.

Near-field vibrations in railway track on soft subgrades for semi high-speed trains

For the development of a high-speed rail network in urbanised areas, ground vibration and associated damage to surrounding structures are major concerns. The problem becomes critical especially in areas with soft soil deposits due to amplification of vibration during Rayleigh wave propagation. In the present study, near field ground vibrations from a high-speed rail ballasted track are predicted for an area which contains predominantly soft marine clay deposits. A two-dimensional finite element model coupled with infinite boundaries is developed in ABAQUS. Using the finite element model, the vibration in terms of peak particle velocity (PPV) and root mean square (RMS) velocity is determined for different train speeds and soil profiles, at varying distances from the track centre. Different soil profiles are considered in this study by varying the thickness and depth of the soft clay layer. From the results, it was observed that maximum ground vibration happens when the train speed is close to the Rayleigh velocity of the soft clay layer. Further, the safe limits for residential and sensitive structures are determined for different conditions based on peak particle velocity. Considering human discomfort during vibration propagation, the vibration level in decibel scale is determined for different track configurations.

Similarity assessment of using helium to predict smoke movement through buildings with double skin façades during building integrated photovoltaics fires

In comparison to the building attached photovoltaics (BAPVs), Building Integrated Photovoltaics (BIPVs) drive more changes in building envelope. Therefore, tackling the fire safety of building integrated photovoltaic is more complicated due to these changes and the interaction between photovoltaic panels and the building. The photovoltaic fire hazards, including smoke generation of solar glazing, closely affect the fire safety of the building and occupants. This effect is further exemplified in the case of solar double skin façade systems where the stack effect influences smoke spread from ignited integrated photovoltaic panels via the vertical space of plenum in double skin façade. In scientific research field, the sub-scale model or laboratory-scale experiments is often applied to study the building fire smoke spread, which is much less costly, time and effort consuming, compared with full-scale test. However, the major concern of the sub-scale fire tests is providing the efficient but safe ignition source. There are methods such as cold smoke and hot gas (hot smoke test), each of which has their specific limitations on the cost and safety. This paper proposes an alternative method of helium smoke to substitute the real fire test for simulating a real integrated solar façade fire. First the fire dynamic simulator model with helium source is validated by experimental helium test along with particle image velocimetry in terms of helium concentration and flow velocity. The differences between the experiments and simulations are in the acceptable range (23 and 24%). Helium smoke result similarity is then compared to small scale real fire which showed close agreement according to the small coefficient of variation (between 1.6 and 11%).

Rock Physical Properties of Longmaxi Shale Gas Formation in South Sichuan Province, China

Deep shale gas (burial depth > 3500 m) in the Longmaxi Formation of southern Sichuan Province will be the primary target for exploration and development in China for a relatively long period. However, the lack of a physical basis for the “sweet-spots” seismic and well-logging prediction is caused by uncertainty in the rock physical properties of deep shale gas in the research area. Acoustic and hardness measurements were performed on shale samples from a deep layer of the Longmaxi Formation in southern Sichuan. Microtextural characteristics of the shale samples were also analyzed by conventional optical microscopy and scanning electron microscopy. Based on these measurements, the rock physical properties of the shale samples and control factors are discussed. It is shown that the deep shale samples have similar properties to the shallow shale in mineral composition, microtexture, and pore type. However, the organic pore in deep shale samples is relatively undeveloped, while the dissolved pores are more developed. For high-quality shale samples (total organic content > 2%), crystal quartz of biological origin forms the framework of rock samples, resulting in effective dynamic and static properties, reflecting the elastic behavior of rigid quartz aggregates. For organic-lean samples (total organic content < 2%), orientated detrital clay particles take the role of load-bearing grains. Therefore, these shale samples’ overall rock physical properties are mainly controlled by the elastic properties of “soft” clay. The load-bearing grain variation from organic-rich shale samples to organic-lean samples results in an overturned “V”-type change in terms of velocity versus content. Organic-rich shale samples also show an apparent low Poisson’s ratio. Organic-rich shale has a slight velocity–porosity trend, while organic-lean shale shows a significant velocity–porosity trend. In addition, due to the difference in rock microtexture between organic-rich and organic-lean shale, these two kinds of reservoir rocks can be discriminated in cross plots of P-wave impedance versus Poisson’s ratio and Young’s modulus versus Poisson’s ratio. Change in hardness also reflects the control of microtexture, and shale samples with biological-origin quartz as load-bearing grains show higher hardness and brittleness. However, the variation in quartz content has less of an impact on hardness and brittleness in shale samples with clay as the load-bearing grain. Our results provide an experimental basis for the geophysical identification and prediction of deep shale gas layers.