Decompression Wave Research Articles

Establishment of a one-dimensional model for CO2 Pipeline rupture process and design recommendations

Pipelines serve as a critical means of transporting CO2 within Carbon Capture, Utilization, and Storage (CCUS) technology. Elevated transport pressures may lead to unforeseen pipeline ruptures. To provide practical recommendations for the design of CO2 pipelines and mitigate the risk of ruptures, this study establishes a one-dimensional Homogeneous Equilibrium Mixture (HEM) model. The model is currently used to predict the decompression behavior in existing pure CO2 rupture tests. Future work will address rupture tests and predictions involving impure CO2. The results indicate that due to differences in pressure reduction caused by decompression waves, the likelihood of long-range ruptures occurring in density CO2 pipelines is lower compared to supercritical CO2 pipelines. The crack propagation velocity and crack arrest pressure of pipelines designed according to ASME B31.3 are calculated using the High Strength Line Pipe Committee (HLP) model. Although the crack propagation velocity is lower than the decompression wave speed, the crack arrest pressure may fall below the rupture pressure, with the pressure at 1.6 m from the rupture point remaining above the crack arrest level for 1 ms post-rupture, a duration that is especially prolonged in larger-diameter pipelines. It is recommended to consider additional thickness beyond the calculated minimum thickness.

A study on decompression wave propagation characteristics during CO2 pipeline leakage with consideration of gas‐liquid transition

AbstractPipelines stand as the most cost‐effective method for large‐scale transportation of CO2 from a source point to the storage site, especially over extensive distances. The potential for crack propagation following a pipeline rupture highlights the need for precise analysis of decompression wave propagation. To accurately model this, understanding the decompression wave's propagation laws becomes imperative. Although previous studies have predominantly focused on pipeline leaks within the dense phase or supercritical state, the transition from liquid to gas during leakage significantly affects the decompression wave propagation. When a gaseous CO2 pipeline ruptures, the high Joule‐–Thomson coefficient causes a swift temperature plunge, potentially leading to a gas–liquid transition. However, research on how this phase transition impacts the decompression wave characteristics is limited. To address this gap, this study proposes a transition computational fluid dynamics model to predict the decompression wave behavior. The model is validated with an industrial‐scale full‐bore rupture experiment. The results reveal that the gaseous CO2 leakage induces a pressure plateau at a certain distance from the leakage due to the gas‐liquid phase transition. The influences of initial conditions on this pressure plateau and decompression wave are also explored. This study provides valuable insights into understanding the decompression wave behaviors of gaseous CO2 pipelines, which are essential for ensuring the safety and reliability of CO2 transportation within the carbon capture and storage technology chain. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Intraoperative and Postoperative Ultrasonographic Spinal Cord Evaluation of Cervical Double-Door Laminoplasty.

Ultrasonography is a useful tool for the localization, morphology, and characterization of lesions and is increasingly being applied to spinal cord evaluation in cervical spine diseases. However, in conventional cervical laminoplasty, detailed evaluation is difficult because of ultrasound attenuation. Therefore, the purpose of this study was to perform a cervical laminoplasty using a modified surgical technique and evaluate the spinal cord. The spinal cord was evaluated intraoperatively and one week postoperatively in 11 patients with cervical compressive myelopathy. Double-door laminoplasty was selected as the surgical method, and the shape and placement of the bone graft between the expanded laminas were devised to reduce ultrasonic attenuation, such that there was a large space in which the dura mater was visible. Intraoperative and postoperative spinal cord decompression, claudication, and pulsation were confirmed in all cases. A more precise diagnosis was possible using ultrasound attenuation using the grafted bone between the laminas as an indicator. Intraoperative and postoperative spinal cord decompression status and wave patterns of modified cervical double-door laminoplasty can be evaluated using ultrasonography. Ultrasound-based evaluations of the spinal cord may provide new insights.

Detecting heart failure from B-mode ultrasound characterization of arterial pulse waves.

This study investigated the sensitivity and specificity of identifying heart failure with reduced ejection fraction (HFrEF) from measurements of the intensity and timing of arterial pulse waves. Previously validated methods combining ultrafast B-mode ultrasound, plane-wave transmission, singular value decomposition (SVD), and speckle tracking were used to characterize the compression and decompression ("S" and "D") waves occurring in early and late systole, respectively, in the carotid arteries of outpatients with left ventricular ejection fraction (LVEF) < 40%, determined by echocardiography, and signs and symptoms of heart failure, or with LVEF ≥ 50% and no signs or symptoms of heart failure. On average, the HFrEF group had significantly reduced S-wave intensity and energy, a greater interval between the R wave of the ECG and the S wave, a reduced interval between the S and D waves, and an increase in the S-wave shift (SWS), a novel metric that characterizes the shift in timing of the S wave away from the R wave of the ECG and toward the D wave (all P < 0.01). Receiver operating characteristics (ROCs) were used to quantify for the first time how well wave metrics classified individual participants. S-wave intensity and energy gave areas under the ROC of 0.76-0.83, the ECG-S-wave interval gave 0.85-0.88, and the S-wave shift gave 0.88-0.92. Hence the methods, which are simple to use and do not require complex interpretation, provide sensitive and specific identification of HFrEF. If similar results were obtained in primary care, they could form the basis of techniques for heart failure screening.NEW & NOTEWORTHY We show that heart failure with reduced ejection fraction can be detected with excellent sensitivity and specificity in individual patients by using B-mode ultrasound to detect altered pulse wave intensity and timing in the carotid artery.

Study on the decompression behavior during large-scale pipeline puncture releases of CO2 with various N2 compositions: Experiments and mechanism analysis

Impurities in the captured CO2 stream from various industrial sources may introduce uncertainty into the transient releases of transportation pipelines. Due to limitations in the experimental scale, there is currently limited analysis of the vertical cross-sectional temperature distribution and the pressure response along the pipeline during the releases of impure CO2. The mechanism by which impurities affect the decompression wave and the alterations in phase-change pathways remains unclear. In this study, building upon the existing large-scale pipeline, we established an impurity injection system. Using the common impurity, N2, as a variable, the decompression behavior of the CO2+N2 mixture in the puncture releases and the influence mechanism of N2 were investigated. The results show that the effect of N2 on sound velocity causes a significant decrease in the decompression wave speed. N2 raises the minimum temperature, and it is more pronounced in large-diameter releases; for instance, the minimum temperature during the 100 mm release is always higher than that in the 50 mm release. The gas-liquid mixture closely follows the dew point line, conforming to the Gibbs equilibrium criterion. The experimental scale mirrors real-world operating conditions, endowing the research findings with practical applicability. Concurrently, it furnishes dependable data for numerical researches.

Bursting Sand Balloons

Using linear elasticity theory, we describe the mechanical response of dry non-cohesive granular masses of Ottawa sand contained by spherical rubber balloons subject to sudden bursting in the earliest instants of the event. Due to the compression imposed by the balloon, the rupture produces a fast radial expansion of the sand front that depends on the initial radius R0, the initial pressure p originated by the balloon, and the effective modulus of compression Ke. The hydrostatic compression approximation allows for the theoretical study of this problem. We found a linear decompression wave that travels into the sand and that induces a radial expansion of the granular front in the opposite direction with similar behavior to the wave but with a slightly lower speed.

Pulmonary artery wave intensity analysis in pulmonary hypertension associated with heart failure and reduced left ventricular ejection fraction.

Wave intensity analysis (WIA) uses simultaneous changes in pressure and flow velocity to determine wave energy, type, and timing of traveling waves in the circulation. In this study, we characterized wave propagation in the pulmonary artery in patients with pulmonary hypertension associated with left-sided heart disease (PHLHD) and the effects of dobutamine. During right heart catheterization, pressure and velocity data were acquired using a dual-tipped pressure and Doppler flow sensor wire (Combowire; Phillips Volcano), and processed offline using customized Matlab software (MathWorks). Patients with low cardiac output underwent dobutamine challenge. Twenty patients with PHLHD (all heart failure with reduced left ventricular ejection fraction) were studied. Right ventricular systole produced a forward compression wave (FCW), followed by a forward decompression wave (FDW) during diastole. Wave reflection manifesting as backward compression wave (BCW) following the FCW was observed in 14 patients. Compared to patients without BCW, patients with BCW had higher mean pulmonary artery pressure (28.7 ± 6.12 vs. 38.6 ± 6.5 mmHg, p = 0.005), and lower pulmonary arterial capacitance (PAC: 2.88 ± 1.75 vs. 1.73 ± 1.16, p = 0.002). Pulmonary vascular resistance was comparable. Mean pulmonary artery pressure of 34.5 mmHg (area under the curve [AUC]: 0.881) and PAC of 2.29 mL/mmHg (AUC: 0.833) predicted BCW. The magnitude of the FCW increased with dobutamine (n = 11) and correlated with pulmonary artery wedge pressure. Wave reflection in PHLHD is more likely at higher pulmonary artery pressures and lower PAC and the magnitude of reflected waves correlated with pulmonary artery wedge pressure. Dobutamine increased FCW but did not affect wave reflection.

Analysis Model of Crack Arrest for Supercritical CO2 Pipelines Containing Impurities

CO2 transport pipelines, as a critical link in CCUS technology, are more prone to fracture propagation under the effects of environment and high pressure due to the special characteristics of CO2, resulting in ductile fracture incidents. However, the commonly used original Batelle two curves method (BTCM) has large errors applied to CO2 pipelines containing impurities. In this paper, a corrected BTCM based on a hoop stress calibration factor was proposed to evaluate the crack arrest ability of CO2 pipelines. The reliability of the modified model was verified based on the experiments data. The results show that the GERG-2008 equation of state is more suitable in predication of decompression wave velocity, and fracture propagation velocity model with a correction factor of ccf =2.0 was verified in quite good agreement with experiment results. This corrected BTCM that can be directly applied to engineering, provided theoretical basis and suggestions in the design and safe operation of CO2 pipelines containing impurities.

Experimental study of decompression wave characteristics and steel pipe applicability of supercritical CO2 pipeline

High-strength pipeline steel is the optimal choice for continuously transporting large amounts of carbon dioxide (CO2) in the future Carbon capture, utilization and storage (CCUS) industrial chain, and supercritical CO2 (S–CO2) is the ideal phase state from an emitter to an onshore storage site. In CCUS projects, it is very indispensable to carry out the suitability of high steel-grade pipelines to ensure the safe operation of pipelines. It is considered a catastrophic incident for creatures and equipment once pipeline failure when fractures or propagation occurs. In this paper, the fracture propagation velocity of X70, X80, and X90 pipeline materials is calculated base on the high strength line pipe (HLP). Meanwhile, three sets of full-bore fracture (FBR) experiments of S–CO2 pipelines were conducted with similar initial status on an industrial-scale setup, and the decompression wave velocity was obtained with the data acquisition system. The result shows that the initial decompression wave velocity of S–CO2 is about 270 m/s, and the pressure plateau is between 6.8 and 7.3 MPa, corresponding to the decompression wave velocity, which is about in the range of 100–220 m/s. After that, the decompression wave velocity prediction model was established based on the homogeneous equilibrium method (HEM) and the equation of state (Eos), and the prediction results are more conservative than the experimental results. To ensure that the pipeline will not ductilely fracture in the event of a leakage or rupture, X70, X80 and X90 grade steel pipeline design wall thickness and minimum arrest toughness values are determined based on the two-curve method (TCM), respectively. Furthermore, a CO2 pipeline design model is developed based on the experimental data and decompression wave calculation method. The significant experimental data could be used for safety assessment and theoretical model validation in the CO2 transport pipeline and is useful in developing better fracture control models.

Impact induced compression and decompression waves in porous meta-materials modeled using a continuum theory of phase transitions

Porous meta-materials with both regular and random microstructure are of intense research interest today due to their interesting dynamical properties, including but not limited to, their acoustic band structure, shock absorption properties, and fracture toughness. Some of these materials can exist in a rarefied or densified state depending on the state of stress, and recover their original configuration after a cycle of loading and unloading. Often, they exhibit a hysteretic stress–strain response under quasistatic uniaxial compression. As such, many aspects of their mechanical behavior can be captured using a continuum theory of phase transitions. In this work, the dynamical behavior of such materials is explored. It is shown that the impact problem for these materials can result in propagating shocks, phase boundaries, and fans. The impact problems admit multiple solutions for the same set of initial and boundary conditions leading to non-uniqueness. This non-uniqueness can be remedied using a nucleation criterion and kinetic laws, as is known from the continuum theory of phase transitions. The fan solutions which arise in decompressive impact problems have not received much attention in the literature and may be regarded as a novel contribution of this work. The analysis presented here may have applications in the dynamic behavior of a broad class of porous materials including architected truss-like metastructures and random fiber networks.

Primary versus iatrogenic (post-PCI) coronary microvascular dysfunction: a wire-based multimodal comparison

BackgroundAlthough there are studies examining each one separately, there are no data in the literature comparing the magnitudes of the iatrogenic, percutaneous coronary intervention (PCI)-induced, microvascular dysfunction (Type-4 CMD) and...

Numerical study of the transient behaviors of vapour-liquid equilibrium state CO2 decompression

The vapor–liquid equilibrium (VLE) state of CO2 commonly appears in pipelines for its transport, refrigeration systems, and large-scale trans-critical cycle systems. However, the behavior of sudden leaks in such systems remains unclear, which poses a challenge in assessing the risk of leakage. This work is focused on the decompression behavior of VLE state CO2 with different volume fractions of vapor phases in high-pressure pipeline leakage, specifically with the development of a computational fluid dynamics (CFD) model with a nonequilibrium phase transition and the real gas model. The results suggest that the Peng-Robinson Equation of State (PR EoS) is more conservative in predicting the degree of superheat than that of Span-Wagner (S-W) EoS and GERG-2008 EoS. Moreover, it is found that the initial volume fraction of the vapor phase in VLE state CO2 plays a crucial role in determining the characteristics of sudden leakage, such as pressure, temperature, and decompression wave speed both inside and outside the pipe. However, the position of the Mach disk remains unaffected by the initial volume fraction of the vapor phase. The initial vapor volume fraction of 0.2 has the most significant impact on the transient behaviors of the leakage, that is, the speed of the initial decompression wave is approximately 1.46 times slower than that of pure liquid CO2, the pressure and temperature start to decrease approximately 0.46 ms after those of pure liquid CO2, which is about 5.1 times later. Additionally, the peak pressure of the near-field jet is 6.3% higher and the maximum velocity is 11.4% higher than that of pure liquid CO2. It hopes that this work will contribute to the improvement of research models that assess the consequences of potential high-pressure pipeline rupture scenarios.

Fracture process characteristic study during fracture propagation of a CO2 transport network distribution pipeline

The transportation of carbon dioxide (CO2) from the capture point to the pooling site through distribution tubes is a crucial link in the carbon capture, utilization, and storage (CCUS) chain. Existing experiments have not been conducted to study the full-scale fracture of the CO2-distributed pipelines, the pressure and temperature evolution inside the pipe during crack initiation, fracture extension, and stopping have not been revealed. The rate of fracture extension velocities has not been quantitatively described, and the crack morphology has not been analyzed. This paper conducted the first supercritical CO2 pipeline full-scale fracture experiment based on a novel experimental setup with a total length of 21.7 m and the inner diameter of 98.3 mm, 16.7 m of which is the main pipeline and 5 m is the sacrificial pipeline. After the sacrificial pipeline rupture, high-frequency transducers were used to measure the change in fluid pressure, and multilayer thermocouples monitored the temperature distribution in four cross-sections within the pipe. Moreover, the decompression wave propagation velocity of supercritical CO2 and sacrificial pipeline fracture velocity has been obtained and calculated, respectively. The microscopic morphology of the cracks obtained by scanning electron microscopy revealed the failure mechanism of the sacrificial pipeline with prefabricated defects. This work establishes a reliable experience for industry-scale CO2 pipelines and creates a pipeline design foundation for higher security transport in the future.

Hemodynamic effects of a dielectric elastomer augmented aorta on aortic wave intensity: An in-vivo study

Dielectric elastomer actuator augmented aorta (DEA) represents a novel approach with high potential for assisting a failing heart. The soft tubular device replaces a section of the aorta and increases its diameter when activated. The hemodynamic interaction between the DEA and the left ventricle (LV) has not been investigated with wave intensity (WI) analysis before. The objective of this study is to investigate the hemodynamic effects of the DEA on the aortic WI pattern. WI was calculated from aortic pressure and flow measured in-vivo in the descending aorta of two pigs implanted with DEAs. The DEAs were tested for different actuation phase shifts (PS). The DEA generated two decompression waves (traveling upstream and downstream of the device) at activation followed by two compression waves at deactivation. Depending on the PS, the end-diastolic pressure (EDP) decreased by 7% (or increased by 5–6%). The average early diastolic pressure augmentation (Pdia¯) increased by 2% (or decreased by 2–3%). The hydraulic work (WH) measured in the aorta decreased by 2% (or increased by 5%). The DEA-generated waves interfered with the LV-generated waves, and the timing of the waves affected the hemodynamic effect of the device. For the best actuation timing the upstream decompression wave arrived just before aortic valve opening and the upstream compression wave arrived just before aortic valve closure leading to a decreased EDP, an increased Pdia¯ and a reduced.WH.

Effects of initial flow velocity on decompression behaviours of GLE CO2 upstream and downstream the pipeline

During the transportation of high-pressure liquefied CO2, the CO2 may be in a gas-liquid equilibrium state (GLE) in the pipeline due to the harsh environment or the sudden opening and closing of the source valve. Research on the transient decompression characteristics of CO2 under various conditions is helpful to improve the prediction accuracy of pipeline cracks and the establishment of far-field models of CO2 leakage to improve accurate boundary conditions. In this paper, a nonequilibrium liquid-gas phase transition decompression model is established, and the Span-Wagner equation of state (S-W EoS) and Lee model are embedded to accurately predict the thermophysical properties of CO2. Then, the simulation results obtained by the decompression model established in this paper are compared with the experimental data and the prediction results of decompression models used by other scholars for verification. The results showed that the predicted results were in good agreement with the experimental data. Finally, the effects of the initial flow velocity and phase slip on CO2 decompression characteristics are studied. The phase slip has a minor effect on the CO2 transient behaviours, but the initial flow velocity has significant effects on the CO2 decompression characteristics inside and outside the pipeline. In addition, it was found that the decompression wave speed in downstream pipeline was relatively faster, and the pressure plateau value was lower.

Pulmonary Artery Wave Intensity Analysis in Pulmonary Hypertension Due to Left Heart Disease

<h3>Purpose</h3> Wave intensity analysis (WIA) uses simultaneous changes in the pressure and flow velocity to determine wave energy, type and timing of traveling waves in the circulation. Pulmonary artery WIA has not been studied in patients with heart failure. We hypothesise that WIA can differentiate patients with combined pre- and post-capillary pulmonary hypertension (PH) from isolated post-capillary PH. <h3>Methods</h3> Right heart catheterisation was performed using a balloon floatation catheter. Pressure and velocity data were acquired simultaneously using a dual-tipped pressure and doppler flow sensor wire. The data were processed offline using customised Matlab software. <h3>Results</h3> We studied 20 patients with heart failure [Table]. Eight patients had backward compressions wave (BCW). The representative wave intensity (dI) pattern with pressure (P) and velocity (U) profile is shown in Figure 1. The black line denotes total pressure, velocity and wave intensity, the blue dotted line denotes forward going waves and red dotted lines denotes backward going waves. Figures 1a and 1b show the groups with and without a BCW. Typically a forward compression wave (FCW) in early systole (related to right ventricular systole) is followed by a forward decompression wave (FDW) in diastole. Fig1a shows a BCW immediately following the FCW in systole, which may be indicative of wave reflection in the pulmonary circulation. Patients who displayed a BCW had significantly higher pulmonary artery pressure, TPG, PVR and significantly lower PAC. <h3>Conclusion</h3> The presence of a BCW on pulmonary WIA may identify patients with combined pre- and post-capillary PH.

Immersed body motion: near-bottom added mass effects

The presence of a solid boundary can cause a substantial increase in added mass due to a solid body movement in the fluid. If the body is very close to the boundary, the added mass increases at an even greater rate. The added mass can be of considerable importance in many dams and hydropower, water/ocean, civil and mechanical engineering problems; furthermore, it has an important effect on the dynamics of the vibrating body in the fluid. The principal aim of this paper is to define a novel model to properly evaluate the near-bottom effects of the added mass and to investigate the instantaneous pressure field due to a body movement that changes the thickness of a compressible thin fluid film close to a solid boundary. The body movement can be due to the application of an external force according to Newton's law. This phenomenon is studied theoretically in this paper, and a hydrodynamic model able to compute the instantaneous pressure field in the thin fluid film is drawn out. The fluid film thickness variation, producing compression and decompression waves, tends to reduce the mean body displacement due to external forces, but it generates both high-frequency fluctuations in body force and in body displacements. For the first time, this novel study provides the near-bottom added mass and justifies the strong body accelerations measured in the laboratory experiments that have not been evidenced in the theoretical studies in the known literature.

The Acoustic Nature of “Storm Nose”, “Supercell” Vortices and Tornadoes

The process of cumulonimbus cloud Cb calvus formation in the middle latitudes of real atmosphere is analyzed in this work. Its transformation from initial lifecycle stage to “maturity” undergoes due to the formation of the waveguide called “aerial acoustic channel” in the troposphere near the level of temperature minimum that is close to 2 km altitude. This “aerial acoustic channel” can be considered as analog of “deep sound channel” that corresponds to the minimal sound speed level. Tropospheric “channel” related to the thermal inversion zone is almost unlimited horizontally. Synchronous generation of two compression waves (ascending one above Cb and descending one inside Cb) is caused by Cb calvus dome ascension. The first one can provoke the aerodynamic draft previously unexplained. The second one results in the growth of its “storm nose” and in the axial and peripheral descending mechanisms in Cb. The penetration of Cb into stratosphere results in the destruction of dynamic balance around Cb top and hence in its unloading in the descending decompression wave. Here the air cools down to the “dew point” in the place of conjugation with parental cloud – due to Snellius law it results in the formation of aerosol “vortex” as condensation front; this “vortex” has calculated value of its generatrix against vertical. Due to D. Snow’s criterion, this vortex forms either “supercell” vortex or tornado vortex.

Experimental visualization and characteristics of bubble nucleation during rapid decompression of supercritical and subcooled carbon dioxide

The rapid decompression of sub-cooled and supercritical carbon dioxide was investigated experimentally using schlieren and regular high-speed photography. An optically accessible expansion tube was designed and constructed. A test campaign with initial pressures ranging from 6.45–9.02 MPa and initial temperatures from 297–308 K was performed. High-speed schlieren imagery was used to visualize the decompression waves, evaporation waves, and an oscillatory phase change region present in the blowdown process. The time history of pressures at different locations along the expansion tube were recorded using fast response pressure transducers. Image and pressure signal analyses were performed to extract decompression wave speeds and evaporation wave speeds. Results were compared to analytical models and other experiments reported in the literature. The relationship between pressure undershoot and wave speed to the initial conditions was analysed.

Coronary haemodynamics associated with left ventricular hypertrophy in aortic stenosis and hypertension

Abstract Background Left ventricular hypertrophy (LVH) occurs in both aortic stenosis (AS) and hypertension (HT) due to an increase in afterload. However, in AS there is an increase in resting coronary flow (per gram of LV) while in HT it is reduced. Wave intensity analysis (WIA) is a well-established method of characterising and quantifying the energies that drive coronary flow. Energies propagating from the proximal vessel (aorta and systemic arteries) interact with energies travelling from the distal end (myocardial microcirculation). WIA allows the separation of these energies into the waves that drive cyclic changes in coronary flow. Purpose We aimed to compare coronary flow patterns in LVH secondary to AS with coronary flow patterns in LVH secondary to HT. Methods Thirty-one participants were recruited (mean age 63, 18 female), 10 with LVH and severe AS, 11 with LVH and HT, and 10 with no LVH and no AS. Participants underwent invasive pressure and Doppler velocity measurements in each of the left coronary arteries and echocardiography. We applied WIA. Results Mean resting coronary flow per gram of LV tissue (Fig. 1) was increased in participants with LVH secondary to AS (1.62±0.60 ml/min/g) and reduced in participants with LVH secondary to HT (0.49±0.27 ml/min/g), compared to participants with no LVH and no AS (1.47±0.73 ml/min/g). We observed marked differences between the magnitudes of the waves driving coronary flow in the three groups (Fig. 2). Forward and backward travelling waves are shown above and below the line respectively. Waves causing acceleration of coronary forward flow are shown as black and waves causing deceleration are shown in white. Wave 6, the backwards decompression wave (BDW), is particularly important for myocardial perfusion. The BDW corresponds to the diastolic 'suction' of blood down the coronary arteries during myocardial relaxation. The energy of the BDW was increased in LVH secondary to AS (31.1x103 W m–2 s–2) but was reduced in LVH secondary to HT (12.3x103 W m–2 s–2) (p&amp;lt;0.05), compared to participants with no LVH and no AS (14.3x103 W m–2 s–2). The energy of the BDW correlated with LV cavity pressure (r=0.84, p&amp;lt;0.001) and diastolic time (r=−0.62, p&amp;lt;0.001) only in LVH secondary to AS participants. In contrast, the BDW correlated with LV mass (r=−0.49, p=0.03) in participants with LVH secondary to HT and with no LVH and no AS, but not in participants with LVH secondary to AS. Conclusions In hypertension, LVH is associated with reduced mean coronary flow and reduced myocardial “suction” during diastole, presumably by the reduction in myocardial compliance associated with diastolic dysfunction. However, in AS the large pressure gradient between the LV cavity and the aorta results in a large contractile force which is generated in systole and then released in diastole. This large diastolic force overwhelms any local impairment caused by the hypertrophied myocardium and contributes to high resting coronary flow in AS. Funding Acknowledgement Type of funding sources: None.