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The purpose of this paper is to use dynamic meshing to perform CFD analyses of a NACA 0012 airfoil fitted with a morphing trailing edge (TE) flap when it undergoes static and time-dependent morphing. The steady CFD predictions of the original and morphing airfoils are validated against published data. The study also investigates an airfoil with a hinged TE flap for aerodynamic performance comparison. The study further extends to an unsteady CFD analysis of a dynamically morphing TE flap for proof-of-concept and also to realise its potential for future applications.

An existing parametrization method was modified and implemented in a user-defined function (UDF) to perform dynamic meshing which is essential for morphing airfoil unsteady simulations. The results from the deformed mesh were verified to ensure the validity of the adopted mesh deformation method. ANSYS Fluent software was used to perform steady and unsteady analysis and the results were compared with computational predictions.

Steady computational results are in good agreement with those from OpenFOAM for a non-morphing airfoil and for a morphed airfoil with a maximum TE deflection equal to 5 per cent of the chord. The results obtained by ANSYS Fluent show that an average of 6.5 per cent increase in lift-to-drag ratio is achieved, compared with a hinged flap airfoil with the same TE deflection. By using dynamic meshing, unsteady transient simulations reveal that the local flow field is influenced by the morphing motion.

An airfoil parametrisation method was modified to introduce time-dependent morphing and used to drive dynamic meshing through an in-house-developed UDF. The morphed airfoil’s superior aerodynamic performance was demonstrated in comparison with traditional hinged TE flap. A methodology was developed to perform unsteady transient analysis of a morphing airfoil at high angles of attack beyond stall and to compare with published data. Unsteady predictions have shown signs of rich flow features, paving the way for further research into the effects of a dynamic flap on the flow physics.

This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics include: theory – domain decomposition/partitioning, load balancing, parallel solvers/algorithms, parallel mesh generation, adaptive methods, and visualization/graphics; applications – structural mechanics problems, dynamic problems, material/geometrical non‐linear problems, contact problems, fracture mechanics, field problems, coupled problems, sensitivity and optimization, and other problems; hardware and software environments – hardware environments, programming techniques, and software development and presentations. The bibliography at the end of this paper contains 850 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1996 and 2002.

Irregular windy loads are loaded for a wind turbine. This paper aims to determine the form of gear failure and the working life of the gear system by assessing the dynamic strength of gears and dynamic stress distribution.

The helical planetary gear system of the wind turbine growth rate gearbox was investigated, and while a variety of clearance and friction gear meshing processes were considered in the planetary gear system, a finite element model was built based on the contact–impact dynamics theory, solved using the explicit algorithm. The impact stress of the sun gear of the planetary gear system was calculated under different loads. An integrated planetary gear meshing stiffness, and the error of system dynamic transmission error were investigated when the planetary gear meshes with the sun or ring gears.

The load has little effect on the sun gear of the impact stress which was known. The varying stiffness is different while the planetary gear meshes with the sun and ring gears. There were differences between the planetary gear system and the planetary gear, and with load, the planetary gear transmission error decreases.

This study will provide basis knowledge for the planetary gear system.

Gear transmissions are widely utilized in practice. This paper aims to uncouple the crack feature from the cracked time-varying mesh stiffness (TVMS) and investigate the effects of the crack on the nonlinear dynamics of a spur gear pair.

An approximate method to simulate the cracked TVMS is proposed by using an amplitude modulation function. The ratio of mesh stiffness loss is introduced to estimate the TVMS with different crack depths and angles. The dynamic responses are obtained by solving a torsional model which takes the non-loaded static transmission error, the backlash and the cracked TVMS into account. By using the bifurcation diagram, the largest Lyapunov exponent (LLE) and dynamic mesh force, the influences of crack on nonlinear behaviors are examined. The dynamic characteristics are identified from the phase diagram, Poincaré map, dynamic mesh force, time series and FFT spectra.

The comparison between the healthy and cracked gear pairs indicates that the crack affects the system motions, such as the obvious changes of impact force and unpredictable instability. Besides, the additive and difference combination frequencies can be found in periodic-1 and -2 motions, but they are covered in periodic-3 and chaotic motions. Deeper crack is an important determinant of the nonlinear behaviors at a higher speed.

The research provides an interesting perspective on cracked TVMS and reveals the connection between crack and nonlinear behaviors of the gear pairs.

Gives a bibliographical review of the error estimates and adaptive finite element methods from the theoretical as well as the application point of view. The bibliography at the end contains 2,177 references to papers, conference proceedings and theses/dissertations dealing with the subjects that were published in 1990‐2000.

In this study, dynamic mesh method is implemented on a real coded genetic algorithm to demonstrate gain in computational time as well as in higher performance for optimized parameters. Since the differences developed at each step in geometries of new members are not significant, therefore, it is possible to use dynamic mesh methods for new members. In this work, because the population members are obtained by modifying the pervious ones, each member is considered as one step of geometry‐change of a deforming body, for examples, a wing inflating, deflating or cambering.

This study aims to numerically investigate the multi-phase flow and thermal physics inside gearboxes, which is critical to the theoretical analysis of energy transfer.

To explore the churning power losses, a three-dimensional numerical model of the gearbox is built using the RNG k–e turbulence model and three alternative moving mesh strategies (i.e. the dynamic mesh [DM], sliding mesh and immersion solid methods). The influence of the rotational speed on the transient flow field, including the oil distribution, velocity and pressure distribution and the churning losses, is obtained. Finally, the time-dependent thermo-fluid state of the gearbox is predicted.

The findings show that the global DM method is preferable for determining the flow structures and power losses. The rotational speed exerts a significant effect on the oil flow and the wheel accounts for most of the churning losses. Based on the instantaneous temperature distribution, the asymmetric configuration leads to the initial bias of the high-temperature region towards the pinion. Additionally, the heat convection efficiency of the tooth tip is slightly higher than that of the tooth root.

An in-depth understanding of the flow dynamics inside the gearbox is essential for its optimisation to decrease the power and enhance heat dissipation during operation.

This paper seeks to outline a forward swept wing (FSW) design problem to reduce the optimization time and cost and to compare it with previous backward swept wing (BSW) results to see the differences.

Dynamic mesh technique was used in the design of a transonic FSW by coupling it with heuristic algorithms. To obtain the initial FSW mesh from BSW domain, a modified dynamic mesh method was developed. It was also compared with experimental results.

It is observed that the drag coefficient can be reduced by 15 percent in 500 calculations while the lift coefficient is tried to be close to the design value determined at the beginning as a design constraint. Especially, the taper ratio change direction differs from previous BSW optimization.

It is the first time that the dynamic mesh technique is used for obtaining the mesh structures of the new FSW members through genetic optimization. A modified dynamic mesh was used to convert BSW domain to FSW, which means a huge movement for the cells. A physical model of initial FSW is also produced for wind tunnel and tested.

Gives a bibliographical review of the finite element meshing and remeshing from the theoretical as well as practical points of view. Topics such as adaptive techniques for meshing and remeshing, parallel processing in the finite element modelling, etc. are also included. The bibliography at the end of this paper contains 1,727 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1990 and 2001.

The purpose of this paper is to calculate the meshing stiffness of nutation face gear considering the roughness, establish the calculation method of time-varying meshing stiffness of rough tooth surface and analyze the influence of roughness, load and other factors on the meshing stiffness of tooth surface.

The Weierstrass–Mandelbrot (W-M) function in the Majumdar–Bhushan model is used to characterize the rough contact line of the tooth surface, the normal height and radius of the micro convex body are calculated and the contact flexibility of the contact point of the tooth surface is obtained. The contact flexibility and the bending shear deformation flexibility obtained previously are substituted into the improved deformation compatibility equation for iterative calculation, and the time-varying meshing stiffness of the nutation face gear considering the roughness is obtained.

Compared with ABAQUS finite element simulation results, it is found that the meshing stiffness curve of rough tooth surface is more gentle than that of smooth tooth surface, the meshing stiffness value is smaller and the meshing stiffness change is smaller at the position where the number of gear teeth coincide changes.

In the process of calculating contact deformation, the fractal theory W-M function is used to characterize the contact line of the rough nutation face gear, and the deformation coordination condition considering roughness is improved. Therefore, the method of time-varying meshing stiffness considering roughness can obtain more accurate results, which provides theory and data for the subsequent dynamics analysis of the nutation face gear transmission.