Arthur E. Curry

Bio: Arthur E. Curry is an academic researcher. The author has contributed to research in topics: Rotor (electric) & Rubbing. The author has an hindex of 2, co-authored 2 publications receiving 9 citations.

Influence of rubbing on rotor dynamics, part 1

Abstract: The results of analytical and experimental research on rotor-to-stationary element rubbing in rotating machines are presented. A characterization of physical phenomena associated with rubbing, as well as a literature survey on the subject of rub is given. The experimental results were obtained from two rubbing rotor rigs: one, which dynamically simulates the space shuttle main engine high pressure fuel turbopump (HPFTP), and the second one, much simpler, a two-mode rotor rig, designed for more generic studies on rotor-to-stator rubbing. Two areas were studied: generic rotor-to-stator rub-related dynamic phenomena affecting rotating machine behavior and applications to the space shuttle HPFTP. An outline of application of dynamic stiffness methodology for identification of rotor/bearing system modal parameters is given. The mathematical model of rotor/bearing/seal system under rub condition is given. The computer program was developed to calculate rotor responses. Compared with experimental results the computed results prove an adequacy of the model.

Influence of rubbing on rotor dynamics, part 2

Abstract: Rotor dynamic behavior depends considerably on how much the specific physical phenomena accompanying rotor rubbing against the stator is involved The experimental results of rotor-to-stator rubbing contact are analyzed The computer code is described for obtaining numerical calculations of rotor-to-stator rubbing system dynamic responses Computer generated results are provided The reduced dynamic data from High Pressure Fuel Turbo Pump (HPFTP) hot fire test are given The results provide some significant conclusions Information is provided on the electronic instrumentation used in the experimental testing

Thermo-Mechanical Modeling of Abradable Coating Wear in Aircraft Engines

Abstract: In modern turbomachine designs, the nominal clearances between rotating bladed-disks and their surrounding casing are reduced to improve aerodynamic performances of the engine. This clearance reduction increases the risk of contacts between components and may lead to hazardous interaction phenomena. A common technical solution to mitigate such interactions consists in the deposition of an abradable coating along the casing inner surface. This enhances the engine efficiency while ensuring operational safety. However, contact interactions between blade-tips and an abradable layer may yield unexpected wear removal phenomena. The aim of this work is to investigate the numerical modeling of thermal effects within the abradable layer during contact interactions and compare it with experimental data. A dedicated thermal finite element mesh is employed. At each time step, a weak thermo-mechanical coupling is assumed: thermal effects affect the mechanics of the system, but the mechanical deformation of the elements has no effect on temperatures. Weak coupling is well appropriated in the case of rapid dynamics using small time step and explicit resolution schemes. Moreover, only heat transfer by conduction is considered in this work. To reduce computational times, a coarser spatial discretization is used for the thermal mesh comparing to the mechanical one. The time step used to compute the temperature evolution is larger than the one used for the mechanical iterations since the time constant of thermal effect is larger than contact events. The proposed numerical modeling strategy is applied on an industrial blade to analyze the impact of thermal effects on the blade's dynamics.

Flexible Multi-Body Simulation of a Complex Rotor System Using 3D Solid Finite Elements

Abstract: The current thesis investigates the question of whether general-purpose FE-codes currently offer sufficient capabilities to perform challenging rotordynamic analyses. The research is carried out on a special industrial diamond coring system acting as an application example. ABAQUS is used to set up a flexible multi-body simulation using 3D solid finite elements. Extensive experimental investigations provide the basis to validate and update the model. A mode-locking phenomenon is observed in the experiments and is well represented by the simulation model.

Sensitivity Analysis of Rotor/Stator Interactions Accounting for Wear and Thermal Effects within Low- and High-Pressure Compressor Stages

Abstract: In the current design of turbomachines, engine performance is improved by reducing the clearances between the rotating components and the stator, which allows for loss decrease. Due to these clearance reductions, contact events may occur between the rotor and the stator. An abradable coating is deposited along the stator circumference as a sacrificial material to lower the contact severity. However, experiments highlighted the occurrence of rotor/stator interactions with high wear depth on the abradable coating as well as high temperature increases within the abradable coating following contacts. This work focuses on the sensitivity analysis of rotor/stator interactions with respect to the rotor angular speed and the initial clearances between the rotor and the stator, taking into account thermal effects within the abradable coating. Convergence analyses are first conducted to validate the numerical model. Then, after a calibration of the thermal model of the abradable coating based on two experimental test cases, the numerical model is used to investigate the cross effects of the angular speed and the initial clearances on the obtained rotor/stator interactions.

Dynamic stress prediction method for rubbing blades

Abstract: The common technique frequently employed in dynamic stress analysis of vibration systems is time-consuming and difficult to solve when dealing with the dynamic systems with nonlinear contacts, such as turbine blades subjected to rubbing faults. To address this deficiency, an approach combining the incremental harmonic balance (IHB) method with the finite element method (FEM) was proposed for predicting the dynamic stress of rubbing blades. First, the finite element model of a warp three-dimensional (3D) entity blade was developed, and its dynamic equation was established by considering the effect of centrifugal force under high speed revolution. Then, as the rubbing fault is highly nonlinear and strong coupling, the IHB method was applied to solve the periodic solutions of the system, and the deformation of each node was obtained. Third, taking the deformation response obtained as initial displacement constraints and imposing it on relevant points, the dynamic stresses were then obtained by using the static analysis in ANSYS. Since employing the IHB method, the transient nonlinear finite element analysis was transformed into the static analysis in the present method, so it significantly raised the solution efficiency. To show the effectiveness of the method, dynamic stress prediction and parameter analysis of a rubbing blade were studied as an example.