Asymmetric Velocity Profiles Research Articles

Characteristics of numbering-up and flow distribution of multi-channel microreactor with 2-D constructal inlet distributors

In this work, the flow distributions of 16-, 8-, 4-, 2-channels microreactors with 2-D constructal inlet distributors were measured. The results showed an increase in channel numbers caused a decreasing uniformity of the flow distribution. Both asymmetrical velocity profiles before a bifurcation point and asymmetrical flow resistance after a bifurcation point played an important role on the flow distribution in microchannels. The uniformity of flow distribution showed a trend of firstly increasing and then remaining unchanged with the increase of Re (4 ∼ 680). The pressure drops of microreactors were also investigated and the empirical method is in the acceptable range for estimating the energy consumption. Extending the channel length after bifurcation point from 124.46 mm to 160.95 mm and incorporating a bypass pressure equalization chamber at bifurcation point could improve the uniformity of flow distribution.

Microfluidic flow tuning via asymmetric flow of nematic liquid crystal under temperature gradient

In this work, efficient microfluidic flow rate tuning based on the asymmetric flow of nematic liquid crystal 5CB under a horizontal temperature gradient is studied. Rectangular microchannels with the width of 100 μm are fabricated through soft lithography and treated with homeotropic surface anchoring conditions. Polarized optical microscopy is applied to explore the unique optical anisotropic characteristics of the nematic liquid crystal. The asymmetric velocity profiles in the microchannel are obtained by particle tracking velocimetry. The effects of temperature, flow rate, and aspect ratio on the velocity profile and split ratio of the asymmetric flow are quantitatively studied for the first time, while the mechanism of the flow asymmetry of the nematic liquid crystal is discussed. The results show that the asymmetric flow of the nematic liquid crystal occurs after the horizontal temperature gradient is applied, with the velocity in the heated region markedly higher than its counterpart. The split ratio of the asymmetric flow increases with the increase in the temperature gradient and the decrease in the flow rate. The aspect ratio influences the asymmetric flow through approaches of average velocity and surface anchoring strength, while the former is more distinct. The impacts of temperature gradient, flow rate, and aspect ratio on the flow asymmetry of nematic liquid crystals are caused by the coupling between physical properties, velocity field, and director field. Microchannels based on the asymmetric flow characteristics of nematic liquid crystals can act as a novel kind of temperature-controlled microvalve to achieve efficient microfluidic flow tuning.

Anthropomorphic Tendon-Based Hands Controlled by Agonist-Antagonist Corticospinal Neural Network.

This article presents a study on the neurobiological control of voluntary movements for anthropomorphic robotic systems. A corticospinal neural network model has been developed to control joint trajectories in multi-fingered robotic hands. The proposed neural network simulates cortical and spinal areas, as well as the connectivity between them, during the execution of voluntary movements similar to those performed by humans or monkeys. Furthermore, this neural connection allows for the interpretation of functional roles in the motor areas of the brain. The proposed neural control system is tested on the fingers of a robotic hand, which is driven by agonist-antagonist tendons and actuators designed to accurately emulate complex muscular functionality. The experimental results show that the corticospinal controller produces key properties of biological movement control, such as bell-shaped asymmetric velocity profiles and the ability to compensate for disturbances. Movements are dynamically compensated for through sensory feedback. Based on the experimental results, it is concluded that the proposed biologically inspired adaptive neural control system is robust, reliable, and adaptable to robotic platforms with diverse biomechanics and degrees of freedom. The corticospinal network successfully integrates biological concepts with engineering control theory for the generation of functional movement. This research significantly contributes to improving our understanding of neuromotor control in both animals and humans, thus paving the way towards a new frontier in the field of neurobiological control of anthropomorphic robotic systems.

On the Origin of “Rotating Instabilities”—Stability and Frequency Studies of Channel Flows

Abstract A group of unsteady flow phenomena in turbomachinery is often referred to as “rotating instabilities.” They occur at flow conditions with very asymmetric velocity profiles, as found downstream of blade rows in axial compressors with large rotor tip clearance in stable operating points close to compressor stall or off-design operating points in steam turbines. In the present work, it is shown that such instabilities do not depend on the blading but also occur in blading-free flow channels. The theoretical proof is carried out with the tools and computational programs of spatial stability theory and Reynolds number dependent jumps in the transverse wavelengths at characteristic perturbation frequencies of the present asymmetric turbulent channel flow are discovered. Experimental investigations in a straight flow channel confirm the calculated frequency field and other characteristics of the perturbations. In agreement to theoretical results, a very asymmetric velocity profile across the channel height was found to trigger disturbances within a limited range of frequencies and not bound to the existence of blading. The notion of rotating instability is misleading in the characterization of this disturbance.

Developing a Computational Model of Lungs for Patients With Acute Respiratory Distress Syndrome

Abstract Acute respiratory distress syndrome (ARDS) is a condition secondary to direct or indirect insult to lungs, leading to acute respiratory failure, and is associated with high mortality. Majority of the ARDS patients require mechanical ventilation, which acts as double-edged sword. Ventilator induced lung injury (VILI) is considered secondary to high inspiratory pressure and cyclical opening during inspiration, and collapse during expiration as suggested by ARDS network clinical trials. Other mechanism for VILI exist secondary to heterogeneous ventilation. To enumerate these mechanisms leading to VILI, a computational fluids dynamics (CFD) study was performed in this study to explore the flow patterns and the pressure distribution in a human tracheobronchial airway model from third to sixth generation branches. The authors validated the computational methodology and analyzed the results to obtain velocity profiles in the primary and secondary flow directions. The study investigated the role of various flow velocities corresponding to Reynolds number (Re) from 100 to 2000 on the pressure drops along branches and bifurcation zones. The identification of secondary flow patterns was critical in understanding the development of asymmetric velocity profiles in the triple bifurcation geometry. The observed patterns in pressure drops and velocity profiles over the laminar flow regime pave the path toward further development of a numerical model to aid treatment for patients with ARDS.

Shear layers and plugs in the capillary flow of wormlike micellar gels.

Wormlike micellar solutions formed by long-chained zwitterionic surfactants show gel-like rheology at room temperature and have recently been found to exhibit other complex and interesting rheological features. We study the dynamics of these wormlike micellar gels in a pipe-flow scenario using particle imaging and tracking velocimetry and report the existence of plug flows with strong wall slip and non-parabolic velocity profiles for different surfactant concentrations and imposed flow rates. We rationalize these results as features of a developing transient flow of a viscoelastic solution in space and time. We show that evolution of shear layers is governed by intermittent flows, asymmetric velocity profiles and flow induced heterogeneity. Our experiments shed light on the transient fluid dynamics of wormlike micelles in simple geometries and highlight the complexity of flows involving wormlike micellar gels and similar soft matter systems in canonical flows.

Elastic Resistance and Shoulder Movement Patterns: An Analysis of Reaching Tasks Based on Proprioception.

This study departs from the conventional research on horizontal plane reach movements by examining human motor control strategies in vertical plane elastic load reach movements conducted without visual feedback. Here, participants performed shoulder presses with elastic resistances at low, moderate, and high intensities without access to visual information about their hand position, relying exclusively on proprioceptive feedback and synchronizing their movements with a metronome set at a 3 s interval. The results revealed consistent performance symmetry across different intensities in terms of the reach speed (p = 0.254-0.736), return speed (p = 0.205-0.882), and movement distance (p = 0.480-0.919). This discovery underscores the human capacity to uphold bilateral symmetry in movement execution when relying solely on proprioception. Furthermore, this study observed an asymmetric velocity profile where the reach duration remained consistent irrespective of the load (1.15 s), whereas the return duration increased with higher loads (1.39 s-1.45 s). These findings suggest that, in the absence of visual feedback, the asymmetric velocity profile does not result from the execution of the action but rather represents a deliberate deceleration post-reach aimed at achieving the target position as generated by the brain's internal model. These findings hold significant implications for interpreting rehabilitation approaches under settings devoid of visual feedback.

Momentum boundary layers in transcritical channel flows

We present well-resolved large-eddy simulations (LES) of a channel flow solving the fully compressible Navier–Stokes equations in conservative form. An adaptive look-up table method is used for thermodynamic and transport properties. We apply a physically consistent subgrid-scale turbulence model, that is based on the Adaptive Local Deconvolution Method (ALDM) for implicit LES. The wall temperatures are set to enclose the pseudo-boiling temperature at a supercritical pressure, leading to strong property variations within the channel geometry. In total seven cases are computed covering different Reynolds numbers, pseudo-boiling positions and pressure values. The hot wall at the top and the cold wall at the bottom produce asymmetric mean velocity and temperature profiles which result in different momentum layer thicknesses. All cases feature a turbulent mass flux which is essential in turbulence modelling. Furthermore, we analyse the turbulent kinetic energy budgets, perform a quadrant and octant analysis of the Reynolds shear stress and employ an invariant map to study the anisotropy in transcritical turbulent channel flows.

An Asymmetric Velocity Profile for Minimizing Wafer Slippage and Settling Time of a Wafer Transport Robot

This paper presents a control solution for minimizing the takt time of a wafer transfer robot that is widely used in the semiconductor industry. To achieve this goal, this work aims to minimize the transfer time while maximizing the transfer accuracy. The velocity profile is newly designed, taking into consideration parameters such as end effector deformation, changes in friction, vibrations, and required position accuracy. This work focused on the difference between the robot’s acceleration and deceleration phases and their contributions to wafer dynamics, resulting in an asymmetric robot motion profile. Mixed cubic and quintic Bezier curves were adopted, and the optimal profile was obtained through genetic algorithms. Additionally, this work combines its newly developed motion profile with an iterative learning control to ensure the best wafer transportation process time. With the presented method, it is possible to achieve a significant reduction in takt time by minimizing wafer slippage and vibration while maximizing robot motion efficiency. All development processes presented in this paper are verified through both simulation and testing.

Numerical Study of the Effects of Asymmetric Velocity Profiles in a Curvilinear Channel on Migration of Neutral Buoyant Particle

The microstructure and suspended particle behavior should be considered when studying the flow properties exhibited by particle suspension. In addition, particle migration, also known as Segré–Silberberg effects, alters the microstructure of the suspension and significantly affects the viscosity properties of the suspension. Therefore, particle behavior with respect to the changes in mechanical factors should be considered to better understand suspension. In this study, we investigated the particle behavior in asymmetric velocity profiles with respect to the channel center numerically using the lattice Boltzmann method and a two-way coupling scheme. Our findings confirmed that the final equilibrium position of particles in asymmetric velocity profiles converged differently between the outer and inner wall sides with respect to the channel center. This indicates that the mechanical equilibrium position of particles can be changed by asymmetric velocity profiles. In addition, centrifugal force acting on the particles is also important in the study of equilibrium position. These results suggest that the microstructure and viscosity characteristics of a suspension in a pipe could be handled by changes in velocity profiles.

THE USE OF AN ULTRASONIC FLOW METER IN THE ZONE OF INFLUENCE OF INDIRECT SECTIONS OF THE WATER PIPELINE

The accuracy of water flow rate measurement with an ultrasonic flow meter (UFM) is affected by pipeline conditions. On water pipelines, there is often no the required length of direct section, required by the device passport or regulatory documents. Therefore, we conducted experiments using UFM to measure water flow rate in the zone of influence of non-direct sections of the water pipeline. The flow rate was measured in two planes of the pipeline with an offset of 90 o and the average value was taken. Thus, it was expected to take into account the average water velocity for the asymmetric velocity profile. The results of water flow rate measuring with UFM on short direct sections of the water pipeline, limited by pipeline bends sudden constriction of the pipeline, are presented. The greatest influence on the UFM measurement error is the 90 o pipeline bends.

Investigating the Mixture Quality in Multi-Injector Burner Systems—Part I: Experimental Setup

Abstract A new approach to calculate the mixture statistics in multi-injector burner (MIB) systems from a single injector database is presented in the paper. In such systems, the mixture quality is highly sensitive to the flowrate and the skewness of the inflow velocity profile. To determine the mixture fraction statistics from these two parameters for a particular injector in a multi-injector configuration, output-based proper orthogonal decomposition (O-POD) is suggested using results from Reynolds-averaged Navier Stokes (RANS)–computational fluid dynamics (CFD) as the observable. The O-POD mixing database is determined experimentally from two setups: First, the mixture quality in a single injector at ideal inflow conditions is studied. Then the same injector type is investigated in a generic MIB system. To characterize the mixture quality, the mixing probability mass function (PMF) at the injector exit is measured by means of laser-induced fluorescence (LIF) and high speed imaging. The data obtained for both the single injector under ideal inflow and the MIB are presented. These studies of the mixture behavior reveal that an asymmetric inflow velocity profile leads to a significant increase of unmixedness, which is seen as a negative skewness of the mixing PMFs. This effect becomes stronger at higher momentum flux density ratios due to the higher penetration depth of the fuel jets. The application of the O-POD to the database shows that the PMF can be accurately modeled with only three modes.

Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for aero-engine cooling

This study explores the design, analysis, and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number aero-engines. In high speed flight, the compressor bleed air used to cool high temperature turbine blades and other hot components is too hot. Hence, aviation kerosene is applied to precool the compressor bleed air by means of novel air–fuel heat exchangers. Three light and compact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured, with little difference existing in aspects of tube pitches and outer diameters among three heat exchangers. The fuel flows inside a series of parallel stainless serpentine tubes (outer diameter: 2.2, 1.8, 1.4 mm with 0.2 mm thickness), while the air externally flows normal to tube bundles and countercurrent with fuel. Experimental studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet temperatures. Non-isothermal measurements have also been performed to research the effect of heat transfer on pressure drops. The experimental results show that inlet temperatures have significant influence on pressure drops, and higher temperatures lead to higher pressure drops at the same mass flow rate. The hydraulic resistance coefficient decreases quickly with Reynolds number, and the descent rate slows down when Re > 6000 for all three heat exchangers. Additionally, the pressure drop on heat transfer states is less than that on isothermal states for the same average temperatures. Moreover, the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches, and an asymmetric M-shaped velocity profile is generated in the cross-section of sector channels.

Numerical and Experimental Investigation into the Aerodynamic Benefits of Rotorcraft Formation Flight

The use of formation flight to achieve aerodynamic benefit applied to rotorcraft has, unlike its fixed-wing counterpart, received little attention in the literature. This document presents a proof-of-concept of rotorcraft formation flight from two independent investigations: a numerical study of a fully articulated helicopter influenced by an upstream helicopter wake and a wind-tunnel experiment featuring two small-scale helicopter models with fixed-pitch blades. Both cases feature a representation of two helicopters in a diagonal, staggered formation aligned on the advancing side of the main rotor, but do not simulate directly comparable flight conditions. The vertical and lateral alignment of the two helicopters is varied in order to observe the achievable reductions in main rotor power required during cruise flight. The wind-tunnel experiment data yield an estimated maximum total power reduction for the secondary aircraft of approximately 24%, while the numerical models yield reductions between 20% and 34% dependent on flight velocity. Both experiments predict a higher potential for aerodynamic benefit than generally observed for fixed-wing formations, which is attributed to the asymmetric velocity profile induced by the wake of the upstream rotor. Optimal lateral alignment of both experimental and numerical results is found to feature overlap of the rotor disk areas, rather than tip-to-tip alignment, as a result of the circular rotor disk area. Experimental data show an optimal vertical alignment of the secondary rotorcraft below the primary, due to the self-induced vertical displacement of the rotor wake, which is absent from the numerical results due to the application of a flat wake assumption. The results show a promising potential for rotorcraft formation flight, though due to the limited nature of the models used, conclusions cannot be generalized. The potential aerodynamic benefit indicated by the present study invites further research in the field of rotorcraft formation flight.

Numerical study on the effect of circumferential position of ultrasonic transducers on ultrasonic cross-correlation flowmeter performance under asymmetric air flow profile

There are several ultrasonic flowmeter technologies such as transient time, cross-correlation, Doppler and etc. The performance of different types of ultrasonic flowmeters under disturbed flow profile due to elbow at upstream has been well studied recently except the cross-correlation type. The ultrasonic cross-correlation flowmeter (UCCF) has different mechanism of flow measurement in comparison with other types of ultrasonic flowmeters that strongly requires its own studies. In case of disturbed flow profile in pipe, due to asymmetrical velocity profile, the UCCF accuracy and required calibration factor are strongly dependent on the circumferential position of ultrasonic transducers on the pipe. Study on UCCF transducers circumferential position and specifying transducers proper position could incredibly improve the UCCF accuracy. The effect of transducers circumferential position on the accuracy in both single path and multipath has not been investigated for a UCCF so far. In this work, Computational Fluid Dynamics (CFD) simulations were conducted using turbulence model of RSM (Reynolds Stress Model) Stress-ω to simulate the asymmetrical air flow profile inside the elbow and the connected straight pipe in order to study the effect of circumferential position of transducers on calibration factor for special type of ultrasonic flowmeters ,UCCF, at different Reynolds numbers and various locations of flowmeter, for the first time. Moreover, the effects of Reynolds numbers and the flowmeter distances from the elbow on the calibration factor were analyzed. Finally, based on calculated calibration factors at different transducer circumferential positions, the best transducers arrangement at different flowmeter locations were proposed for single and multipath cross-correlation flowmeter. Also, in multipath ultrasonic cross correlation flowmeter, the optimum number of transducers were investigated.

Asymmetric velocity profiles in Paralympic powerlifters performing at different exercise intensities are detected by functional data analysis

Asymmetries compromise performance in powerlifting and Paralympic powerlifting, but its quantification can be complex. Previous studies consider average or peak values to quantify asymmetries, however this approach does not consider the pattern of movement like velocity profiles. Here we demonstrate that conducting a functional analysis of variance (FANOVA) permits to quantify asymmetries in bench press performance by Paralympic powerlifting at different submaximal intensities. Kinematic data were collected from 10 Paralympic powerlifting athletes performing in bench press at submaximal intensities (50% and 90% of the one-repetition maximum). Linear velocity was quantified considering mean values and the entire waveform. Mean values were compared by analysis of variance (ANOVA) and the waveforms were compared by FANOVA. FANOVA identified asymmetry profiles that ANOVA did not recognize at the highest intensity, which is the closest to a competition. This way, FANOVA can bring advantages to the analysis of competitive performance. FANOVA data analysis identifies asymmetries at higher intensity of effort considering the whole pattern of movement. Therefore, we consider that the FANOVA’s approach may benefit the biomechanical assessment of the Paralympic powerlifting.

Enhancement of the accuracy of ultrasonic flowmeters by applying the PCA algorithm in predicting flow patterns

In the current study, a novel arrangement of acoustic paths with an on-off technique upon ultrasonic waves is proposed to enhance the accuracy and reduce the frequency of calibration of the ultrasonic flowmeter (USFM). In addition, a web of chord probes on the velocity profile with a novel rotating method is also proposed. Twenty velocity profiles, including 19 selected Salami asymmetric velocity profiles and a centrosymmetric developed velocity profile, are combined with the proposed chord-probe mesh to build a novel velocity database. The built database includes 2241 900 sets of 12 mean velocities, ranging from 0.1 m s−1 to 25 m s−1. Furthermore, the principal component analysis algorithm is employed and trained by the developed database to predict the flow patterns in a practically flowing measurement. The predictive ability of the developed algorithm is examined in 10 different scenarios. In all cases in this study, it is found that the proposed USFM can not only measure the volumetric flow rate of the asymmetric flows with extremely high accuracy, but can also eliminate the influences of flow regimes and the effects of the installed location.

Genesis of Antibiotic Resistance (AR) LXXV: Turbulence Modeling of Simplified Severe Sepsis Protocol‐2 (SSSP‐2), NCT01663701: Simulation of Contributing factors that Protract & Métier Torque Thrusted LPE Aggregates’ in Coandă effect Cause Critical Closing Pressure (CCP)

Hypothesis: EGDT-ERP is directly inducing blood volume expansion, altering the BP, alter the velocity, shear stress, hematocrit forming an LPE aggregate’ and an adverse pressure gradient in vivo smite NFP lead to CCP subsequent CVA/comatose. An effort is made to test a unifying (holistic) hypothesis that has the potential to lull LPE aggregates, alongside AR clinical persisters in the cerebrovascular capillary bed with intrinsic torque of LPE (bluff body) in tandem dragging on the capillary lumen, alongside LE (large eddies), vortices would rupture true capillaries eliciting CCP in an asymmetric velocity profile through anisotropic mode with the collapse of NFP is tested with fluid flow. Geometry: We take inspiration from the impact of torque-drag of a moving object in time sequence: a: torque- and drag sustain damage to the runway – correlate LPR torque – drag on the capillary bed: https://www.youtube.com/watch?v=DFOynlRYT54YouTube©– (time scale: seconds)– b: https://www.youtube.com/watch?v=u5axFVRdNRU; c:splash on the landing: https://www.youtube.com/watch?v=9poWj5eu5rE- (time scale: seconds) – d:https://www.youtube.com/watch?v=2u7jY3V-GJ0– rejected take-off – LPE aggregates lead abrupt occlusion; Governing equations: Darcy's law: Q=kA∆P/μl, -Eq3.27, where Q=discharge flow rate, k=permeability, A= cross-section of the media (blood), ∆P=pressure drop, μ=viscosity, L=length, derived eq. 3.28 – 3.34; (p104-105, ISBN 9780128024089); Torque: τ = r x F, where force F, that act on a particle at position, r(p250 eq;7.6 (ISBN 9780521198110). Experimental Observation: The following experimental observations is an archetype for our hypothesis ad hoc momento. PMID:27319318: Fig2 b, d, f, h compares to the Fig 1, III and V, E, would be lysed passing through the occlusion, releasing lysate, in turn, activating L, P, and E forming LPE; Fig 3d-F represent an LPE aggregate in vivo of sepsis cohort in NCT01663701; Fig 4c the stenosed vessels energy level declined; Fig 5c location II, high energy location VI favor LPE aggregate upstream causing CCP; penultimate to losing NFP, CVA cloture comatose. PMID: 31297646: indicate that RBC(E) aggregate occurs upstream of stenosis forming thin cell free layer (CFL) and decreased flow velocity are in favor of our hypothesis. PMID 31010931 Fig 5 C in the CLP group continuous accumulation of heparin sulfate in the hippocampus of sepsis model (PMID 31297646, PMID 29195076), Fig 7E, implicit of LPE aggregate at the arterial end of the capillary bed;p9213 reinternalize cecum–a trauma-lack≡DDx!; ( PMID: 30720464 PMID: 31337421; PMID: 31201739), patient-specific, TM-CFD; Simulation: Our effort to simulate for water/sewage flow system indicate that a. monitors the aggregate formation, b. utilizes the degreaser/blood-thinning agent, c. coating the pipe agents to repair glycocalyx-endothelium to restore the structure and laminar flow. At present, attempting the simulation of role of CFL in eliciting the adverse pressure gradient / vasomotion in the terminal arteriole - exchange vessels - postcapillary venule in vivo.

Effects of inflow boundary layer on the wake of a radially non-uniform porous disk

This study presents the results of an experimental investigation focusing on the effects of the inflow boundary layer on the wake characteristics of a 0.12 m diameter porous disk with radially non-uniform porosity in terms of mean flow, turbulence, and wake scaling. Two-dimensional two-component particle image velocimetry measurements within the wake are performed up to 7.5 diameters downstream as the disk is lowered deeper into a boundary layer that is representative of a neutral atmospheric boundary layer over a flat terrain. Results show that otherwise symmetrical wake velocity profiles that exist outside the boundary layer get skewed and sheared around the disk centerline in the boundary layer due to the inflow wind shear. The turbulent kinetic energy, its production, and Reynolds shear stress levels in the wake get asymmetrical around the centerline of the disk such that the production of turbulent kinetic energy is observed to be higher above centerline. Due to the inflow shear, the wake centerline gets shifted downwards (i.e., toward the wind tunnel wall), which is in contrast to the observations on real wind turbine wakes in the literature where the wake actually lifts up. The asymmetrical and skewed velocity profiles both in the streamwise and cross-stream directions can be collapsed onto a single function by using proper wake scaling parameters based on the ratio of local strain to average strain within the velocity profile calculated separately for either side of the wake.

Large-eddy simulation of turbulent channel flow at transcritical states

We present well-resolved large-eddy simulations (LES) of a channel flow solving the fully compressible Navier–Stokes equations in conservative form. An adaptive look-up table method is used for thermodynamic and transport properties. A physically consistent subgrid-scale turbulence model is incorporated, that is based on the Adaptive Local Deconvolution Method (ALDM) for implicit LES. The wall temperatures are set to enclose the pseudo-boiling temperature at a supercritical pressure, leading to strong property variations within the channel geometry. The hot wall at the top and the cold wall at the bottom produce asymmetric mean velocity and temperature profiles which result in different momentum and thermal boundary layer thicknesses. Different turbulent Prandtl number formulations and their components are discussed in context of strong property variations.