Rotational Speed Research Articles

Experimental investigation and numerical prediction on heat transfer performance of a high speed radially rotating heat pipe

A CFD model considering the saturation pressure difference inside radially rotating heat pipes (RRHP) was proposed to reveal the heat transfer characteristics. To validate the model, copper-water RRHPs were designed and experimented. These experiments were conducted under equivalent centrifugal accelerations ranging from 100 g to 1500 g, with heat inputs varying from 40 W to 240 W. The centrifugal force has a significant influence on heat transfer in the evaporator, leading to the observed of two different working states in the RRHP: forced convection and pool boiling. An unstable transition state may be observed between these two states. As the rotation speed increased, the occurrence of pool boiling gradually suppressed and the heat transfer performance of the RRHP decreased. At 100 g, the minimum thermal resistance was 0.1792 K/W and at 1500 g the minimum thermal resistance slightly increased to 0.2369 K/W. The numerical results showed demonstrated strong agreement with the experiments, with an overall error below 10 %. Subsequently, a working condition diagram was included to provide a dimensionless description for the RRHP heat transfer behaviours based on the Weber number and Bond number. Finally, the heat transfer performance of RRHP under centrifugal accelerations ranging from 2000 g to 1000 g was simulated. The results indicated that even under 10000 g, RRHP can still maintain the thermal resistance at 0.2527 K/W. And the model can be used to further investigate the potential application of different RRHPs in high-speed rotating machinery.

Dynamic diffusion characteristics of airflow and coal dust during the mining process based on MRF: A numerical simulation study

Turbulence generated by rotation of shearer has a great impact on the distribution of dust. The MRF method of multiple reference frame was employed to simulate airflow and dust distribution during mining process. The distribution of cutting dust under different airflow velocities, cutting speeds, and cutting direction (against or follow the direction of airflow) were compared and analyzed. Results show that the generated cutting dust using MRF method tends to move horizontally and vertically. As the speed of airflow increases, vertical characteristics diminish. Simultaneously, horizontal dissipation rises with the deviation of airflow speed. The increase of rotational speed augments the distance covered by cutting airflow, including vertical offset and windward motion. Moreover, the elevated drum speed amplifies airflow speed in the sidewalk and the primary influence range is approximately 80 m. When cutting in the downwind direction, the airflow exhibits a pronounced vertical and horizontal offset behind the drum. Conversely, when cutting in the upwind direction, these characteristics are less evident, resulting in a more uniform spatial distribution of cutting dust in the downwind direction. The majority of dust generated when cutting against the airflow tends to move in the low-altitude area, contributing to a more disordered pattern.

Optimization of Hammer-Disc Mill Parameters During Producing Gluco-mannan Flour Using Taguchi Method

Porang tubers contain glucomannan, which has health benefits for the human body. However, glucomannan also contains calcium oxalate, which is toxic. A Hammer-Disc mill (HDM) machine was used to separate glucomannan and calcium oxalate, categorized as a mechanical process. This study aims to optimize the parameters of the Hammer-Disc Mill machine for producing glucomannan flour by using the Taguchi Method. The selected parameters are the mass of the porang chip, motor rotation speed, and the distance of the hammer blades. The Taguchi Method was used to design an experiment using the Orthogonal Array L9 (3 factors, 3 levels). In this study, statistical analysis was carried out using Analysis of Variance (ANOVA) to determine each parameter's effect on glucomannan production. The glucomannan granules were taken using a screener of 60-80 mesh. The results show that the input mass parameter of porang chips significantly affects the glucomannan produced, which, F calculating 10,91 was more than f Table 5,41. The contribution of mass input of porang chips in percentage is 85.36%. Based on the results of the best response, the optimal condition for the production of glucomannan flour is to use a mass of 1 kg of porang chip input (level 3), motor rotation speed of 3000 rpm (level 3), and hammer spacing of 1 cm (level 3). By optimizing this parameter it is expected to increase the yield of glucomannan produced by the Hammer-Disc Mill machine.

Optimizing the Landing Stability of Blended-Wing-Body Aircraft with Distributed Electric Boundary-Layer Ingestion Propulsors through a Novel Thrust Control Configuration

The imperative for energy conservation and environmental protection has led to the development of innovative aircraft designs. This study explored a novel thrust control configuration for blended-wing-body (BWB) aircraft with distributed electric boundary-layer ingestion (BLI) propulsors, addressing the issues of sagging and altitude loss during landing. The research focused on a small-scale BWB demonstrator equipped with six BLI fans, each with a 90 mm diameter. Various thrust control configurations were evaluated to achieve significant thrust reduction while maintaining lift, including dual-layer sleeve, separate flap-type, single-stage linkage flap-type, and dual-stage linkage flap-type configurations. The separate flap-type configuration was tested through ground experiments. Control experiments were conducted under three different experimental conditions as follows: deflection of the upper cascades only, deflection of the lower cascades only, and symmetrical deflection of both cascades. For each condition, the deflection angles tested were 0°, 10°, 20°, 30°, 40°, 50°, and 60°. The thrust reductions observed for these three conditions were 0%, 37.5%, and 27.5% of the maximum thrust, respectively, without additional changes in the pitch moment. A combined thrust adjustment method maintaining a zero pitch moment demonstrated a linear thrust reduction to 20% of its initial value. The experiment concluded that the novel thrust control configuration effectively adjusted thrust without altering the BLI fans’ rotation speed, solving the coupled lift–thrust problem and enhancing BWB landing stability.

Fluoride removal using a rotating anode electro-coagulation reactor: Parametric optimization using response surface methodology, isotherms and kinetic studies, economic analysis and sludge characterization

The presence of fluoride in drinking water can cause various diseases, such as dental fluorosis and skeletal fluorosis. The present study aims to intensify the fluoride removal using a rotating anode electro-coagulation (EC) reactor with providing the proper hydrodynamics conditions. This fluoride removal is modeled and optimized using Response Surface Methodology (RSM) and central composite design (CCD) with varying operational parameters (rotation speed: 20–80 RPM, current: 0.2–1.0 A, initial fluoride concentration: 8–40 mg/L and time: 15–75 min). The maximum fluoride removal is obtained as 96.87% (predicted) and 95.40% (experimental) for the optimized process parameters, initial concentration of 32 mg/L, 0.8 A current, 60 min, and 60 RPM of rotating speed. Kinetic analysis reveals that the removal process adheres to a second-order kinetic model, suggesting that the rate of fluoride removal is dependent on the concentration of fluoride ions present. Isothermal studies indicate that the effective sorption of fluoride onto the generated flocs follows a sips isotherm. The optimal cost analysis is carried out to determine the operational cost as 0.256 USD/m3 for F removal of 93.49% at initial concentration 24 mg/L, time 50 min, current 0.7 A, and rotation 70 rpm and presenting a cost-effective solution for fluoride mitigation. Further, characterizations of the resultant sludge through X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), and the Toxicity Characteristic Leaching Procedure (TCLP) confirmed the safe disposal potential of the sludge. The findings show a promising approach for fluoride removal, combining high efficiency, economic viability, and environmental safety.

A Lab-Scale Evaluation of Parameters Influencing the Mechanical Activation of Kaolin Using the Design of Experiments.

This research investigates the mechanical activation of kaolin as a supplementary cementitious material at the laboratory scale, aiming to optimize milling parameters using the response surface methodology. The study evaluated the effects of rotation speed and milling time on the amorphous phase content, the reduction in crystalline kaolinite, and impurity incorporation into the activated clay through the Rietveld method. The results demonstrated that adjusting milling parameters effectively enhanced clay activation, which is crucial for its use in low-carbon cements. High rotation speeds (300/350 rpm) and prolonged grinding times (90/120 min) in a planetary ball mill increased the pozzolanic activity by boosting the formation of amorphous phases from kaolinite and illite and reducing the particle size. However, the results evidenced that intermediate milling parameters are sufficient for reaching substantial degrees of amorphization and pozzolanic activity, avoiding the need for intensive grinding. Exceedingly aggressive milling introduced impurities like ZrO2 from the milling equipment wear, underscoring the need for a balanced approach to optimizing reactivity while minimizing impurities, energy consumption, and equipment wear. Achieving this balance is essential for efficient mechanical activation, ensuring the prepared clay's suitability as supplementary cementitious materials without excessive costs or compromised equipment integrity.

Automated Microfluidics-Assisted Hydrogel-Based Wet-Spinning for the Biofabrication of Biomimetic Engineered Myotendinous Junction.

The muscle-tendon junction (MTJ) plays a pivotal role in efficiently converting the muscular contraction into a controlled skeletal movement through the tendon. Given its complex biomechanical intricacy, the biofabrication of such tissue interface represents a significant challenge in the field of musculoskeletal tissue engineering. Herein, a novel method to produce MTJ-like hydrogel yarns using a microfluidics-assisted 3D rotary wet-spinning strategy is developed. Optimization of flow rates, rotational speed, and delivery time of bioinks enables the production of highly compartmentalized scaffolds that recapitulate the muscle, tendon, and the transient MTJ-like region. Additionally, such biofabrication parameters are validated in terms of cellular response by promoting an optimal uniaxial alignment for both muscle and tendon precursor cells. By sequentially wet-spinning C2C12 myoblasts and NIH 3T3 fibroblasts, a gradient-patterned cellular arrangement mirroring the intrinsic biological heterogeneity of the MTJ is successfully obtained. The immunofluorescence assessment further reveals the localized expression of tissue-specific markers, including myosin heavy chain and collagen type I/III, which demonstrate muscle and tenogenic tissue maturation, respectively. Remarkably, the muscle-tendon transition zone exhibits finger-like projection of the multinucleated myotubes in the tenogenic compartment, epitomizing the MTJ signature architecture.

Gearbox fault identification using auto-encoder without training data from the damaged machine

Deep learning methods work well in machine diagnostics where operating conditions affect diagnostic signals. Classifiers are often used for fault identification, but these methods require training data sets measured for each fault. The solution to the lack of data is autoencoder-based network models, but these models can only detect, not identify faults.This article presents a new fault identification method based on auto-encoders (AE-based Fault Identification Technique AE-FIT) that does not require training data from the damaged machine. This method diagnoses pinion gearboxes operating under variable conditions (variable load, load-induced rotational speed, and temperature). The result of the technique is an interpretable diagnostic spectrum (AE-based Interpretable Order Spectrum AE-IOS).The method has been tested on two laboratory benches to detect misalignment, unbalance, and gearbox degradation. The damages introduced were used to validate a technique based on an auto-encoder trained only with data from undamaged machines.

Impacts of alkaline washing pretreatment on municipal solid waste incineration fly ash (MSWI FA) and resulting geopolymers

The safe disposal and utilization of municipal solid waste incineration fly ash (MSWI FA) has emerged as a crucial challenge, primarily due to elevated levels of heavy metals and chlorides. In this study, the influence of key factors in different pretreatment methods on the physicochemical properties of MSWI FA was analyzed, and the effects and mechanism of different pretreatment methods on the resulting geopolymers were studied. Under the conditions of a liquid-solid ratio (L/S) of 7 mL/g, a rotational speed of 500 r/min, and a stirring time of 20 min, the alkali washing with 1 mol/L NaOH solution exhibited better effect than water washing. The total content of chlorides and the content of soluble chloride in AFA (MSWI FA with alkali washing) were 1.53 % and 0.85 %, respectively. Alkali washing had a greater influence on the migration of heavy metals from MSWI FA to filtrate than water washing. Meanwhile, alkaline washing exhibited better effect in calcium retention and sulfur removal. The pretreatment process enhanced the gel formation in geopolymers, subsequently exerting a significant influence on the compressive strength and leaching concentration of heavy metals. Thermogravimetric analysis showed the bound water content in AG (8.46 %) was the greatest in all simples, indicating that exerted the most pronounced impact on the gel formation during geopolymerization. And, the lower ratio of Si-O-Na to Si-O-T in AG (0.20) indicated a longer geopolymeric chains, which explained the higher compressive strength of geopolymers during the initial curing period. This article provides a new pretreatment method to promote the resource utilization of MSWI FA.

Effect of underwater friction stir welding parameters on AA5754 alloy joints: experimental studies

The water as a welding environment may generate serious technological and metallurgical problems but in certain cases, the physicochemical properties of water can be used effectively, e.g., to impart the specific properties of welded materials. The purpose of the work was verification of effectiveness of the water cooling of aluminium alloy AA5754 for various sets of technological parameters of underwater friction stir welding (UFSW). For the joints performed with the range of parameters of rotational speed: 475–925 rpm and welding speed: 47.5–95 mm/min, the following examinations were carried out: visual tests, radiographic tests, static tensile test, fractography (SEM, scanning electron microscope) analysis, and surface texture analysis performed with 3D measurement system. All of the joints were characterized with some amount of flash. Besides, depending on the values of selected parameters, the defects arising from inadequate stirring were found—tunnel defects and melting. The best appearance of the joint was obtained for the set of parameters of 925 rpm and 47.5 mm/min. The samples of the same joint were found to be of the highest mechanical properties—ultimate tensile strength (UTS) of 194 MPa and elongation (A) of 9.2%. The results were confirmed by the fractography analysis, which in this case indicated the ductile fracture mode. Dynamic plastic behaviour strongly depends on the process parameter values, which was reflected in the results of surface texture analysis. The parameter selection resulted in significant changes in the roughness results (from 8 to 14.2 µm depending on the sample) as well as the flow ring distance of the weld (from 20 to 50 µm depending on the sample).

Predicting MHD mixed convection in a semicircular cavity with hybrid nanofluids using AI

This study presents a numerical analysis of magnetohydrodynamic (MHD) mixed convection in a semicircular enclosure containing a rotating inner cylinder and filled with nanofluids and hybrid nanofluids. The investigation explores the effects of Al2O3-TiO2-SWCNT-water hybrid nanofluids with varying nanoparticle compositions, as well as Al2O3-water, TiO2-water, and SWCNT-water nanofluids. The analysis includes the development of an artificial neural network (ANN) model to predict outcomes, achieving 97.34 % accuracy in training and 97.41 % in testing for the average Nusselt number. The study examines the impact of Reynolds number (Re), Richardson number (Ri), Hartmann number (Ha), cylinder rotation speed (Ω), cylinder size, and nanoparticle volume fraction (φ) on heat transfer and fluid flow. Key findings include a 6.98 % increase in heat transfer for SWCNT-water nanofluid from Ri = 1 to Ri = 10, a reduction in heat transfer with higher Hartmann numbers, and a significant 21.12 % enhancement when cylinder speed increases to Ω = 10 compared to a stationary cylinder. Larger cylinder sizes also improve convective heat transfer, with a 66.14 % increase for SWCNT-water nanofluid. Additionally, higher concentrations of SWCNT and Al2O3 in hybrid nanofluids enhance heat transfer performance.

Construction of Kinetic Model of Vacuum Arc Magnetic Fluid Under External Magnetic Field

The external magnetic field is an important control method of vacuum arc at present. Because of its high efficiency and economy, it has become an important method to study the kinetic model of vacuum arc magnetic fluid. Therefore, the kinetic model of vacuum arc magnetic fluid under the external magnetic field is constructed. Firstly, the mass conservation equation, radial momentum conservation equation, axial momentum conservation equation, energy conservation equation, electromagnetic equations are analyzed. The boundary conditions of the dynamic model are cathode boundary, anode boundary and fluid wall boundary. The fluid dynamics calculation software FLUENT is used as the calculation platform, and its secondary development is carried out. Combining VC++self-programming and self-defined macro functions, according to the boundary conditions, the kinetic model of vacuum arc magnetic fluid under external magnetic field is solved, and the kinetic model analysis of vacuum arc magnetic fluid under external magnetic field is realized. Experimental analysis shows under the action of longitudinal magnetic field, the intensity of longitudinal magnetic field increases, the maximum point of ion rotation speed in the magnetic fluid of vacuum arc moves outward along the edge of vacuum arc, the number density of electrons gradually moves from the central axis to the radial direction, and the high density area increases first and then decreases; Under the action of transverse magnetic field, the intensity of transverse magnetic field increases, the ion pressure in vacuum arc magnetic fluid gradually shifts and increases, and the ion number density also increases.

Research on the efficiency analysis method of 9AT transmission planetary gear system based on power loss

As the core element of power transmission in Automatic Transmission (AT), the planetary gear system has advantages in the gear ratio range, load carrying capacity and transmission efficiency, and its transmission efficiency analysis is an important link in the design of automatic transmission.This paper proposes a method to analyze the transmission efficiency of planetary gear system of 9AT transmission considering power losses. Firstly, based on the hypergraph theory to establish the power transmission roadmap of each gear of the transmission (9AT) and the triangular hypergraph of the four-row planetary gear system, as well as the power flow model of the four-row planetary gear system without considering the power losses, and then the rotational speed, torque, and power change of each gear of the gear system are analyzed through the power spectrum. Secondly, a power flow model considering power losses and circulating power was established to analyze the influence law of different operating parameters (speed, torque, viscosity, gear meshing friction coefficient), and structural parameters (characteristic coefficients of each planetary row) on the transmission efficiency of the system. Finally, the equivalent planetary gear system transmission efficiency experimental bench considering losses is established to measure the transmission efficiency of the two-row planetary gear system at different speeds and torques, and the results of the experimental tests have the same trend with the theoretical calculations, which provides an analytical method to improve the transmission efficiency of the planetary gear system of the 9AT transmission.

Prediction of surface roughness at the machining of densified wood surfaces

ABSTRACT In this research, modeling and interpretation of the effects of the machining parameters on surface roughness (Rz) using artificial neural networks (ANN) and analysis methods (MLP, LVQ and Taguchi Design analysis) werw studied. Black poplar (Populus nigra) was selected as the experimental material. Specimens, which were transversal densified by a thermo-mechanical (TM) process at 0%, 20% and 40% compression ratios. The densified wood was processed at 1000, 1500 and 2000 mm/min feed speeds and in 12,000, 15,000, and 18,000 rpm rotation speeds in a CNC machine by using two different cutters. Rz surface-roughness values were measured. The modeling of Rz with artificial neural networks (ANN) is discussed. While 97% success was achieved in the classification made with multilayer perceptron (MLP) in estimating Rz, this success rate is 100% in the classification made with learning vector quantization (LVQ). MLP and LVQ are operations in the MATLAB R2019b software. Taguchi values were compared with the experimental data results, it was seen that the MSE value was 4.6%, the MAE value was 1.8%, and the RMSE value was 2.1%. These results showed that the presented models can accurately determine the appropriate parameters for the desired Rz. The prediction results and presented models can be applied for targeted industrial applications.

Effects of endplate designs on the performance of Savonius vertical axis wind turbine

In aerodynamic studies, endplates or wingtip devices play a crucial role in enhancing the performance of airfoil blades and minimizing losses. This is particularly important for wind turbines, especially the drag-type Savonius turbine. This paper aims to investigate the effects of different endplate designs. Both experimental works and numerical simulations were conducted on a Savonius rotor with an aspect ratio of 1. A total of eight different endplate geometries and sizes were investigated. The mechanical torque and rotational speed were measured experimentally under various loads with an incoming wind speed of 5.89 m/s. The coefficient of torque (CT) and coefficient of power (CP) were calculated in both the experiments and simulations. The simulation was first validated using data from the literature, and flow characteristics were then scrutinized. The results indicate that the endplates greatly impact the turbine performance, with improvements of up to 299.7 % compared to a turbine without endplates from the experiment. The endplates help prevent flow leakage near the blade edges. In addition to tip losses reducing turbine performance, aerodynamic parasitic drag also contributed to a decrease in CP for the full endplate. The relationship between the aerodynamic parasitic drag with TSR is also reported. By implementing a well-designed endplate, these adverse effects can be mitigated.

Electromagnetic Field and Variable Inertia Analysis of a Dual Mass Flywheel Based on Electromagnetic Control

The moment of inertia of the primary flywheel and the secondary flywheel in a dual mass flywheel (DMF) directly affects the vibration damping performance in an automotive driveline. To enable better minimization of vibration and noise by changing the moment of inertia of the DMF to adjust the frequency characteristics of the automotive driveline, a new variable inertia DMF structure is proposed by introducing electromagnetic devices. The finite element simulation model of the electromagnetic field of an electromagnetic device is established, the electromagnetic field characteristics in the structure are analyzed, and the variation in the electromagnetic force under different air gaps and current conditions is obtained. The electromagnetic force test system of the electromagnetic device is constructed, and the validity of the finite element simulation analysis of the electromagnetic field of the electromagnetic device is verified. A mechanical model of the electromagnetic device is established to analyze the characteristics of the displacement of the moving mass in the structure as well as the variation in the moment of inertia of the DMF at different rotational speeds and currents. The maximum adjustable proportion of its moment of inertia can reach 15.07%. A torsional model of the automotive driveline is established to analyze the effect of variable inertia DMF on the resonance frequency of the system under different currents. The results show that the electromagnetic device introduced in the DMF can realize the active adjustment of the moment of inertia and enable the resonance frequency to decrease with increasing rotational speed, which expands the idea of optimizing the vibration damping performance of the DMF and provides a reference for better control of the torsional vibration of the automobile or other mechanical transmission systems.

Influence of tool rotational speed in butt-joint friction stir welding (FSW): a thermo-mechanical simulation of AA6061

Friction Stir Welding (FSW) is a solid-state welding technique that involves joining two pieces of material by rotating a non-consumable pin at high RPM. This rotation generates heat through friction between the tool and the plates, enabling the welding process without the need for filler metal. Invented by the British Welding Institute (TWI) in 1991, FSW is renowned for creating strong welds and is widely used in the automotive and aerospace industries, in those industries the aluminum alloys are indispensable due to their unique combination of properties. This study focuses on how variations in rotational speed influence temperature distribution, the width of the heat-affected zone, and Von-Mises stress distribution in welded aluminum alloy 6061 sheets, this research aims to provide a comprehensive understanding of these effect, therefore the findings are expected to contribute to optimizing FSW parameters and enhancing weld quality. The analysis was conducted using the finite element method and ALTAIR software.

Dissipation Effects in the Tea Leaf Paradox

The Tea Leaf Paradox (TLP) describes unsteady fluid motions which help entrain and deposit suspended particles at the center of rotation. Various applications depend on the TLP for particle separations—spanning orders of magnitude in length scales—making it an important problem in fluid mechanics. Despite papers describing the phenomenon, the efficacy of particle separation using the TLP remains unclear as to the relative importance of, for example, hydrostatics, particle-fluid density ratio, wall friction, liquid bath aspect ratio and the rotation speed. The dynamics involved are notably complex and require a careful tuning of each variable. In this study, we have investigated the role of the limit of the aggregation dynamics in rotational flows within 3D-printed vessels of various sizes in tandem with particle imaging to probe the dissipation effects on the particle motions. We have found that the liquid bath aspect ratio limits how much aggregation may occur for a particle-fluid density ratio greater than unity (e.g., ρp/ρf>1), where ρp is the density of the particle and ρf is the ambient fluid density.

Real-Time Identification and Nonlinear Control of a Permanent-Magnet Synchronous Motor Based on a Physics-Informed Neural Network and Exact Feedback Linearization

This work proposes a novel method for the real-time identification and nonlinear control of a permanent-magnet synchronous motor (PMSM) based on a Physics-Informed Neural Network (PINN) and the exact feedback linearization approach. The proposed approach is presented in a direct-quadrature framework, where the quadrature current and the rotational speed are selected as outputs and the direct and quadrature voltages are selected as inputs. A nonlinear difference equation is selected to describe the physical dynamics of the PMSM, and a PINN is designed based on the aforementioned structure. A simplified training scheme is designed for the PINN based on a least-squares structure to facilitate online training in real time. A nonlinear controller based on exact feedback linearization is designed by considering the nonlinear model of the system identified based on the PINN. Therefore, the proposed approach involves identification and control in real time, where the PINN is trained online. In order to track the reference for the rotational speed, a nonlinear controller with integral action based on exact feedback linearization is designed based on a linear quadratic regulator. As a result, the proposed approach can be used to identify the system to be controlled in real time, and it is able to track any small change in the real model; in addition, it is robust to both external and internal disturbances, such as variations in torque load and resistance. The proposed approach is evaluated through simulation and using a real PMSM, and the results of reference tracking are evaluated under disturbances. The identification performance is evaluated by using a Taylor diagram under closed-loop and open-loop structures, where ARX and NARX structures are used for comparison. It is thereby verified that this novel proposed control approach involving a PINN-based model can adequately track the dynamics of a PMSM system, where the performance of the proposed nonlinear control is maintained even when using the identified model based on the PINN.

Validation of a Methodology To Assess The Flutter Limit Cycle Oscillation Amplitude of Low-Pressure Turbine Bladed-Disks - Part II: Rotational Speed Effects

Abstract The effect of the operating conditions on the vibration amplitude trends of an isolated low-pressure turbine rotor is described. The study utilizes an analytical model correlating the aerodynamic and dry-friction work introduced in Part I of the paper. In this Part II, the analysis has been extended to incorporate the influence of rotational speed. The force distribution and the penetration length of the fir-tree contact surfaces are key parameters within the heuristic micro-slip model used to characterize the friction forces. These parameters change with rotational speed, consequently influencing the dry-friction work involved in the process. The model is closed with numerical simulations to compute the aerodynamic damping, and it is compared against experimental data gathered from the experimental campaign detailed in Part I. The results demonstrate a significant impact of the shaft speed on flutter vibration amplitude. The vibration amplitude has been observed to reach a maximum near the on-design conditions. The analytical model can correctly capture this trend indicating that the essential physics is retained in it. Nonlinear friction, mistuning and 3D unsteady aerodynamics have shown to play a predominant role to explain the change of vibration amplitude with the shaft speed.