Constant Angular Speed Research Articles

An Analysis of the Kinematics and Dynamics Performance of a New Type of Three-Pronged Sliding Universal Coupling

The three-pronged sliding universal coupling is a new kind of three-pronged coupling. The purpose of this study is to demonstrate that, compared with a traditional unequal angular velocity universal coupling (such as the Hooke universal coupling), the universal coupling has the superior characteristics of constant angular speed transmission, simple structure and strong transmission capacity by performing kinematic and dynamic analysis of the new three-pronged sliding constant angular velocity universal coupling. It provides a broad prospect for applications in automotive and other fields. To study its kinematic and dynamic characteristics, directional cosine matrices are utilized as tools to analyze the coordinate systems by establishing simplified geometric models and corresponding motions. Through the analysis of the motions of the input and output shafts and employing the method of single-force element, a set of equilibrium equations for the forces acting on the output shaft and the input shaft are formulated for solution analysis. The research indicates that during the rotation process, there exists a small angular difference between the input shaft and the intermediate shaft, demonstrating the quasi-constant angular velocity characteristics of the new tripod sliding universal coupling. The curves of the forces and force moment acting on each component of the coupling approximate sinusoidal curves. The optimal operating angle range for the new tripod universal coupling is at angle , during which the system exhibits good transmission and mechanical performance. It can be widely used in the automobile industry, tie steel industry and other occasions that require angular transmission. It is especially used in high-speed operation and large transmission capacity.

EVAPORATIVE AIR COOLER THERMAL PERFORMANCE FOR RESIDENTIAL USE

This paper investigates an Evaporative Air Cooler (EAC) thermal performance and energy efficiency, when reducing the air temperature. EAC equipment typically consists of fan, small hydraulic pump and cooling pads. That device is able to provide ventilation only or air cooling trough water evaporative process that increases the air humidity (absolute and relative) and, as consequence, air temperature decreases (dry and wet bulb). The methodology adapts some aspects from ABNT - Brazilian Technical Standards Normative, for air conditioning devices. During tests, the fan rotor operates in 3 (three) angular speeds (RPM) in different ambient conditions for inlet air. Appropriate instrumentation and measurements registration allow to register the behavior of thermal parameters as: dry and wet bulb temperatures (Tdb and Twb, °C), air relative humidity (RH, %), enthalpy (kJ.kg-1), and water mass flow (kg.s-1). Thus, main results are for overall efficiency (η, %) considering the energy conversion from electricity to air flow hydraulic power, and cooling effectiveness (ε, %) is based on heat exchange between water evaporation and airflow rate. As main conclusions, we point out that: a) ↓Tdb for ↓mAir, reaching ΔT~5.0°C and corresponding ΔΦ~20%, when comparing outlet and inlet airflow parameters; b) EAC efectiveness reaches maximum values for lower rotor angular speeds (εEAC ~90%@1300 RPM), in comparison to higher ones; c) For a constant rotor angular speed, EAC performance (CP, εEAC and others) is strongly dependent on air ambient conditions; mAir increases from ~13.8 kg.s-1 up to ~16.5 kg.s-1 when rotor angular speeds goes from 1300 RPM to 1500 RPM.

IMPACT OF SOLID BOUNDARIES AND VISCOSITY OF THE MEDIUM ON THE CONTRIBUTION OF THE INERTIAL AND VORTEX COMPONENTS OF THE NORMAL FORCE OF A ROTATING PLATE. PART 2

Within the framework of the improved method of discrete vortices, generalized for viscous media, a method has been developed for determining the contribution of forces of inertial, vortex and circulation nature to the normal force of a plate moving in a stationary viscous boundless medium accord- ing to an arbitrary law, in the presence of a wall and in a channel. The developed method was tested for the case of instantaneous angular start of the plate and subsequent constant angular speed of rotation (Wagner's problem) in a viscous boundless medium, in the presence of a wall and in a channel, in laminar and turbulent modes. The application of approximate analytical formulas for the components of the induced velocity from a discrete vortex in a viscous medium near the wall and in the channel made it possible to obtain velocity fields that visualize two vortices separated from the edges of the plate and the dynamics of their dispersion in laminar and turbulent regimes of rotation of the plate near the wall and in the channel. The inertial- vortical nature of the normal force of the plate (with the dominance of inertial forces) is confirmed, which rotates after an instantaneous start with the separation of the flow from both its edges, regardless of the presence of solid boundaries and laminar or turbulent flow regimes. It was found that in the case of the laminar regime, the effect of the presence of the wall on the reduced inertial component of the normal force of the plate is insignificant, but the influence of the channel leads to a faster departure of the laminar vortex from the moving edge of the plate, which leads to a gradual increase in the contribution of the inertial component of the normal force of the plate up to 100 % and more when turning the plate perpendicular to the channel walls. Approximately the same happens in the case of the absence of solid boundaries, when a turbulent vortex of a larger size and intensity than the corresponding laminar one moves away from the moving edge of the plate.

A dynamic goniometer-spectrometer with angle-to-time conversion

We present a dynamic goniometer–spectrometer for measuring the refractive index (RI) of transparent triangular prisms by converting the beam deviation angles into time intervals. The proposed measuring scheme allows the automatic determination of the RI simultaneously for several different wavelengths by measuring the time intervals between the moments of autocollimation of the reference and refracted rays reflected from a mirror continuously rotating around the object with constant angular speed. This makes it possible to avoid the use of an expensive ring laser or encoder for angle measurements and to use relatively inexpensive instruments for time measurements, which reduces the cost of measuring equipment. To calculate the RI value, we used the minimum deviation technique. A functional diagram of the measuring equipment is given. A reference prism made of NBK-7 Schott optical glass was experimentally studied and the measurement errors were estimated. The proposed measuring scheme can be used for automated RI measurement and to study the dispersion characteristics of triangular prisms made of optically transparent materials and liquid optically transparent substances filling a hollow triangular prism.

Energy harvesting from friction-induced vibrations in vehicle braking systems in the presence of rotary unbalances

A severe limitation of energy harvesting from friction-induced vibrations in vehicle brakes is that the voltage generated is significant only at low vehicle speeds. The present work suggests a strategy to overcome this limitation by the utilisation of ambient vibrations resulting from rotary unbalances of vehicle components. A realistic model for vibrations in the brake pad of a disc brake under the action of rotary unbalance is used. The brake pad vibration is modelled using a non-smooth stick–slip oscillator in the presence of Stribeck friction. A weightless shaft of rectangular cross-section rotating at constant angular speed and having an unbalanced mass concentrated at its centre is used to model rotary unbalances. It is shown that the rotary unbalance provides parametric excitation to the brake pad mass undergoing friction-induced self-excited vibration leading to synchronising patterns via Neimark–Sacker bifurcation. Such synchronisation is successful in ensuring steady voltage generation over a much wider speed bandwidth. The qualitative nature of the different solution regimes interspersed with periodic intervals are determined by Lyapunov exponents. The technique used to arrive at the Lyapunov exponents in the present discontinuous model is outlined, and MATLAB code for the same is provided in the appendix.

The Effectiveness of Using Continuous Variable Transmission (CVT) in 2WD Buggy Vehicles

Continuous Variable Transmission (CVT) is a transmission system that does not have gears like in manual transmission cars or conventional automatic transmission cars. CVT has the advantage of being able to maintain the proper rotational speed at any time in terms of engine efficiency by changing the speed ratio flexibly and continuously. A continuously variable transmission (CVT) is a transmission that can change steplessly through an infinite effective gear ratio between maximum and minimum. This is in contrast to other mechanical transmissions which only allow a few different gear ratios to choose. The flexibility of the CVT allows the drive shaft to maintain a constant angular speed over the output speed range. Torque is transmitted from the drive to the pulley which is driven by friction acting between the belt and pulley surfaces. Tests were carried out using a dynotest to obtain wheel rotation data and the resulting torque. The loading is given from 3 kg, 5 kg, 7 kg and 8 kg, the engine rpm used is 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm and 8000 rpm. Rear wheel rotation is inversely proportional to the load, the greater the load the rotation will decrease. Load is directly proportional to torque, the greater the load given the torque will increase. The CVT system is still effective for use as a power successor. The power that can be transmitted is still greater than 50%, namely 68%.

Comparative dynamics of mixed convection heat transfer under thermal radiation effect with porous medium flow over dual stretched surface

Due to enhanced heat transfer rate, the nanofluid and hybrid nanofluids have significant industrial uses. The principal objective of this exploration is to investigate how thermal radiation influences the velocity and temperature profile. A water-based rotational nanofluid flow with constant angular speed {Omega } is considered for this comparative study. A similarity conversion is applied to change the appearing equations into ODEs. Three different nanoparticles i.e., copper, aluminum, and titanium oxide are used to prepare different nanofluids for comparison. The numerical and graphical outputs are gained by employing the bvp-4c procedure in MATLAB. The results for different constraints are represented through graphs and tables. Higher heat transmission rate and minimized skin friction are noted for triple nanoparticle nanofluid. Skin coefficients in the x-direction and y-direction have reduced by 50% in trihybrid nanofluid by keeping mixed convection levels between the range 3 <upepsilon le 11. The heat transmission coefficient with raising the levels of thermal radiation between 0.5 < {uppi } le 0.9 and Prandlt number 7 < {text{Pr}} le 11 has shown a 60% increase.

IMPACT OF SOLID BOUNDARIES AND VISCOSITY OF THE MEDIUM ON THE CONTRIBUTION OF THE INERTIAL AND VORTEX COMPONENTS OF THE NORMAL FORCE OF A ROTATING PLATE. PART 1

Within the framework of the improved method of discrete vortices, generalized for viscous media, a method was developed for determining the contribution of forces of inertial, vortex and circulation nature to the normal force of a plate moving in a stationary viscous boundless medium according to an arbitrary law, in the presence of a wall and in a channel. The developed method was tested for the case of instantaneous angular start of the plate and subsequent constant angular speed of rotation (Wagner's problem) in a viscous boundless medium, in the presence of a wall and in a channel, in laminar and turbulent modes. The inertial-vortical nature of the normal force of the plate (with the dominance of inertial forces) was confirmed, which rotates after an instantaneous start with the separation of the flow from both its edges, regardless of the presence of solid boundaries and laminar or turbulent flow regimes. It has been clarified, that in the case of the laminar regime, the influence of the presence of the wall on the reduced inertial component of the normal force of the plate is insignificant, but the influence of the channel leads to a faster departure of the laminar vortex from the front edge of the plate, which leads to a gradual increase in the contribution of the inertial component of the normal force of the plate up to 100% and more at the end of rotation plates. Approximately the same happens in the case of the absence of solid boundaries, when a turbulent vortex of a larger size and intensity than the corresponding laminar one moves away from the leading edge of the plate.

Electromagnetically driven anticyclonic rotation in spherical Couette flow

The electromagnetically driven anticyclonic flow in the wide gap of a rotating concentric spheres system is studied experimentally and numerically in the laminar regime. The working fluid is an electrolyte contained in the spherical gap. The outer sphere rotates at constant angular speed, and the inner sphere is at rest. The electromagnetic stirring is generated due to the interaction of a direct current, which is injected radially through ring-shaped electrodes located at the equatorial zone of each sphere, and a dipolar magnetic field produced by a permanent magnet located inside the inner sphere. Experimental velocity fields in the equatorial plane were obtained with particle image velocimetry. Additionally, full three-dimensional numerical simulations were performed. The high shearing at the equatorial region promotes an instability that can be perceived as a triggering mechanism of four tornado-like vortical structures tilted and entangled in the polar direction. The instability structure rotates in either the cyclonic or the anticyclonic direction, depending on the flow parameters, namely, the angular velocity of the outer sphere and the applied electric current. To the best knowledge of the authors, this is the first time the phenomenon under study is reported with electromagnetic forcing. The numerical results agree quantitatively with the experimental observations.

Failure response of holed aluminum/glass hybrid composite tubes

It is known that aluminum/composite hybrid tubes of aluminum tube wrapped with a composite material on the outside can offer remarkable performance. This study systematically investigates the effect of stacking sequence on the torque capacity of holed aluminum/composite hybrid tubes. The stacked specimens manufactured by the filament winding method, [±452/Al], [90/±452/Al], and [±452/90/Al], are considered in experimental studies. The tubes were tested for torsional characteristics at a constant angular rotational speed. The experimental studies indicated that although monotonic crack propagation was observed in the aluminum tube with the damage starting from the hole wall at an angle of approximately 45° concerning the specimen axis, the damage in hybrid tubes containing a 90° layer occurs in two phases. This causes a step-like formation in the torque–angle curves. Although the ± 45° reinforcement has a profound effect on torque-carrying, it has been observed that the presence of the 90° composite on the aluminum tube in the reinforced tube improves the effectiveness (torque capacity and stiffness) of the subsequent reinforcement. Accordingly, it is understood that the hybrid structure increases the torque-carrying capacity up to 2.6 times compared to the aluminum tube, corresponding to a 20% increase in specific torque value. The stress components that play an important role in the deformation of the hole wall and damage formation processes have been successfully determined by the finite element method. It was found that there was a consistent relationship between the effect of the stacking sequence on the stress distribution and the experimental results. The results of the study are expected to be useful in terms of providing light and sufficient torque performance in case of possible hole-like discontinuity in-service conditions.

A model of a rotating railway wheel for the prediction of sound radiation

The axial symmetry of a railway wheel is taken into account to expand its vibrational response around the circumferential direction using Fourier series. This allows the vibroacoustic problem of the wheel to be formulated in a two-dimensional frame, solving for the dynamic and acoustic variables analytically in the circumferential direction. By adopting an Eulerian approach, the inertial effects associated with the rotation of the wheelset are included in the model, assuming a constant angular speed of rotation. To represent a railway wheelset, the wheel is constrained at the inner edge of the hub and the contribution of the rigid body motion of the wheelset is superimposed on its response. The latter is evaluated analytically under the assumption of small rigid body displacements. The computational efficiency of the proposed methodology is found to be three orders of magnitude greater than a full three-dimensional methodology, without compromising the accuracy. The results are compared in terms of acoustic radiation with the commercial package Ansys, showing similar sound power levels in almost all the frequency range apart from some differences at low frequencies due to the use of an acoustic model based on radiation ratios.

Порівняльна динаміка витікання рідини із ємностей певних геометричних форм в залежності від зміни осі обертання

In metallurgical enterprises, in some plants and factories, in technological processes, pouring of various types of liquids (cast iron, steel, gold, silver, chocolate, etc.) from large containers of various geometric shapes into smaller standard forms by the method of turning the container relative to a fixed point or a fixed axis and pouring over the edge It is important that the flow of liquid is uniform, which in reality is not true even at a constant angular speed of rotation. This paper examines the process of pouring from containers of conical and parabolic shapes, which are the most widely used in practice. In the development of the authors' works on this topic, another mechanism of rotation, which is often found, is considered, namely, rotation relative to the diameter of the upper part of the boiler. We analyze the obtained results of the study of the dynamics of changes in fluid consumption depending on the angle of inclination in comparison with the results of the previous works of the authors and provide conclusions and recommendations. Taking into account these theoretical studies, the operation of rotary mechanisms in each specific case can be adjusted by developing an algorithm of sequential actions that ensure the uniformity of the pouring process.

Optimization on Linkage System for Vehicle Wipers by the Method of Differential Evolution

We consider an optimization problem on the maximal magnitude of angular acceleration of the output-links of a commercially available center-driven linkage system (CDLS) for vehicle wipers on windshield. The purpose of this optimization is to improve the steadiness of a linkage system without weakening its normal function. Thus this optimization problem is considered under the assumptions that the frame of the fixed links of linkage system is unchanged and that the input-link rotates at the same constant angular speed with its length unchanged. To meet the usual requirements for vehicle wipers on windshield, this optimization problem must be solved subject to 10 specific constraints. We expect that optimizing the maximal magnitude of angular acceleration of the output-links of a linkage system would also be helpful for reducing the amplitudes of sound waves of wiper noise. We establish the motion model of CDLS and then justify this model with ADAMS. We use a “Differential Evolution” type method to search for the minimum of an objective function subject to 10 constraints for this optimization problem. Our optimization computation shows that the maximal magnitude of angular acceleration of both output-links of this linkage system can be reduced by more than 10%.

Orientation and Exposure Efficiency of a Solar Tracking Surface in Clear Sky

With regard to the problem of current solar irradiation of the tracking surface by the tracker, this can be rationally assessed using a modeled flux with parameters close to the natural direct in accordance with the maximum transparent atmosphere. As part of the experimental research, the values of the air optical mass index in the zenith angle ranging from 0° to 90° were presented for the surface at sea level. The conducted analysis made it possible to confront the experimental research with the models of the optical air transparency mass index. In order to maximize the energy of the controlled beam of the sun’s rays, the angle of their incidence on the tracking surface by the tracker should be minimized. The modeling results show the actual hourly dependencies, which are average values of the intensity of the multi-year measurement. It was found that seasonal dependencies can be considered as theoretically possible and then used to assess the energy efficiency of the tracking surface. Theoretically, they also correspond to the maximum possible energy efficiency of continuous tracking of the Sun with a two-axis rotary tracker. A polar-rotary tracker is a device where the axis of rotation is parallel to the axis of the earth and orients the tracking surface using the simplest synchronous algorithm with a constant angular speed ω = 15 grad/h. The novelty of the article is a method presenting the combination of a normal trajectory with direction towards the sun. Due to the deviation towards the polar axis, the normal touches the horizon, not at six hours after full sun, but earlier and simultaneously. In this way, an uniaxial pole-rotating tracker provides the same irradiation regime as a biaxial one in terms of the deviation of the tracking surface from the axis of rotation, which is equal to the tilt of the sun.

Numerical Elastic Analysis of Functionally Graded (FG) Polar Orthotropic and Exponentially Varying-Thickness Rotating Disks via Combined Complementary Functions and the Transfer Matrix Methods

In the present paper, the transfer matrix method (TMM) is to be employed for the first time in the open literature for the elastic analysis of variable-thickness disks made of functionally graded (FG) two orthotropic materials. Those materials are assumed to be continuously radially functionally graded (FG) based on the Voigt rule of mixture with two models. An exponential disk profile with two parameters is considered. Effects of the different boundary conditions (free-free, fixed-free, and fixed-fixed) and inhomogeneity indexes on the elastic response of the disk rotating at a constant angular speed are also examined. Additionally, direct numerical solutions of the problem with the complementary functions method (CFM) are presented in tabular forms together with the transfer matrix method solutions in which CFM was used as an assistant tool. It was observed that both location and amplitude of the maximum equivalent stress are affected by the grading models chosen. Such differences become more obvious for small values of the inhomogeneity indexes. The maximum relative error may reach 18% for the two material grading models in fixed-free disks. Consequently, Model-I may be recommended for just the inhomogeneity indexes equal to or greater than 0.5.

Moore–Gibson–Thompson Photothermal Model with a Proportional Caputo Fractional Derivative for a Rotating Magneto-Thermoelastic Semiconducting Material

By considering the Moore–Gibson–Thompson (MGT) equation, the current work introduces a modified fractional photothermal model. The construction model is based on the proportional Caputo fractional derivative, which is a new definition of the fractional derivative that is simple and works well. In addition, the theory of heat transfer in semiconductor materials was used in the context of optical excitation transfer and plasma processes. The proposed model was used to investigate the interaction of light and heat within a magnetized semiconductor sphere rotating at a constant angular speed. The Laplace transform was used to obtain solutions for optical excitation induced by physical field variables. Using a numerical method, Laplace transforms can be reversed. The figures show the effects of carrier lifetime, conformable fractional operator, and rotation on thermal and mechanical plasma waves, which are shown in the graphs. The theory’s predictions were compared and extensively tested against other existing models.

Computational Fluid Dynamics Analysis of the Influence of Gas Content on the Rotordynamic Force Coefficients for a Circumferentially Grooved Annular Seal for Multiple Phase Pumps

Abstract Pumping efficiency and rotordynamic stability are paramount to subsea multiphase pump operation since, during the life of a well, the process fluid transitions from a pure liquid to a mixture of gas in the liquid to just gas. Circumferentially grooved seals commonly serve as balance pistons in pumps while also restricting secondary flow. Prior experimental results obtained with a grooved seal operating with a mixture of air and mineral oil show the seal rotordynamic force coefficients vary significantly with the gas volume fraction (GVF). This paper, complementing an exhaustive experimental program, presents a computational fluid dynamics (CFD) analysis to predict the leakage and dynamic force coefficients of a circumferentially grooved seal supplied with air in an oil mixture with a GVF varying from 0 to 0.7. The test seal has 14 grooves, an overall axial length of 43.6 mm, and radial clearance of 0.211 mm. The 127 mm diameter rotor spins at constant angular speed (Ω = 3500 rpm). The mixture enters the seal at a supply pressure (Pin) of 2.9 bar(a), and the seal exit pressure (Pout) is 1 bar(a). The CFD two-phase flow simulations utilize the Euler–Euler multiphase model to predict the mass flowrate and the pressure field as a function of the operating conditions. Using a multi-frequency shaft orbit motion method, the CFD simulations deliver the variations of reaction force on the rotor with respect to the excitation frequency. For a pure liquid condition (GVF = 0), both the CFD and experimental results produce constant stiffness, damping, and added mass coefficients. The experimental and CFD results demonstrate the seal rotordynamic force coefficients are quite sensitive to the GVF. When introducing a small amount of air into the oil (GVF = 0.1), the direct damping coefficient increases by approximately 10%. For operation with a mixture with inlet GVF &amp;gt; 0.1, the cross-coupled stiffness coefficients develop strong frequency-dependent characteristics. In contrast, the direct damping coefficient has a negligible variation with excitation frequency. The CFD predictions, as well as the experimental results, evidence that air injection in a liquid stream can significantly change the seal rotordynamic characteristics, and thus can affect the rotordynamic stability of a pump. An accurate CFD analysis provides engineers to design reliable grooved seals operating under two-phase flow conditions.

Interaction of angular velocity and temperature rise in the thermo-inertia bifurcation buckling of FG laminated nanocomposite annular plates

The present study examines the asymmetric stability of a functionally graded (FG) nanocomposite shear deformable annular plate with a constant angular speed in the thermal environment. For the first time, this phenomenon is investigated for a structure augmented with graphene platelets (GPLs). The displacement field in the annular system is estimated depending on the first-order shear deformation plate assumptions called FSDT. Moreover, the von-Kármán premise of geometrically nonlinear relations is utilized to achieve the equilibrium equations and related edge constraints. To recognize the stability relations in a linearized style, the adjacent equilibrium criterion is utilized. Applying a combined solution procedure consisting of the trigonometric expansion along the hoop axis and the generalized differential quadrature along the radius axis (TE-GDQ), the achieved stability equations are solved, and novel numerical results are obtained. An eigenvalue problem is solved to calculate the critical temperature rise for thermal buckling and the required angular velocity for rotating buckling. Based on the various GPL parameters, geometric properties, and boundary conditions, novel numerical findings are developed to illustrate the interplay of thermal and rotational buckling.

ОЦЕНКА ПАРАМЕТРОВ КЛОТОИДНОЙ ТРАЕКТОРИИ ВХОДА В ПОВОРОТ КОЛЕСНОЙ МАШИНЫ

A theoretical assessment of the influence of the translational speed of a wheeled vehicle and the angular rotation speed of its steered wheels on the main characteristics of the clotoid curve is carried out. The calculations were carried out with the following initial parameters characterizing the structural and geometric features of the wheeled vehicle: the longitudinal base of the machine is 2.6 m; the distance between the axes of the front axle pins is 1.8 m; the maximum angle of rotation of the driven wheels is 33 °30'. The speed of the translational movement of the machine and the angular rotation speed of the controlled wheels was varied. The results of the evaluation are as follows. With a constant angular rotation speed of the front wheels of 0.195 s-1 and with a change in the speed of translational motion in the range from 0.57 m/s to 1.78 m / s, the maximum abscissa of the clotoid curve increased from 0.113 m to 1.074 m – almost tenfold, and the maximum ordinate from 1.703 m to 5.141 m - approximately three times. At a constant translational speed of 1.41 m/s and with a change in angular velocity in the range from 0.0974 s-1 to 0.292 s-1, which corresponds to the time interval of turning the wheels at a maximum angle from 2 s to 6 s, it was obtained: the maximum abscissa decreases with an increase in angular velocity from 2.585 m to 0.305 m - by 8.5 times, and the maximum ordinate - from 7,689 m to 2.79 m - 2.8 times. The calculation established that the minimum radius of curvature of the trajectory at the end of the section of the entrance to the turn is equal to 5,061 m, which corresponds, as it should be, to the value of the minimum theoretical radius given in the technical characteristics of some wheeled vehicles with the accepted initial parameters.

Spectral analysis of a non‐homogeneous rotating Timoshenko beam

AbstractIn this paper we examine the spectral analysis of a spatially non‐homogeneous Timoshenko beam mounted on the periphery of a rigid root rotating about its axis at a constant angular speed. The junction between the beam and the root is assumed to be elastically restrained and damped. The unbounded operator associated to the physical problem in the associated Hilbert space is non‐self‐adjoint and with a compact resolvent. We show that under some hypotheses on the physical properties of the beam, there exists a Riesz basis of root vectors of this unbounded operator. Furthermore, the solution of the initial value problem has an expansion in terms of this Riesz basis, uniform with respect to the time in a bounded interval.