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The heat transfer by radiation and natural convection in a two‐dimensional, air‐filled square enclosure with a vertical partition of finite thickness and varying height was investigated numerically in the laminar regime. The horizontal end walls are assumed to be adiabatic, and the vertical walls are at different temperatures. Calculations are made by using a finite volume method and an efficient numerical procedure is introduced for calculating the view factors, with shadow effects included. The results indicate that the partition does not significantly modify the heat transfer rate through the cavity, especially at high Rayleigh numbers, provided that its height is less than 90 per cent of the cavity height. The effects of radiation on the velocity and the temperature fields and the overall heat transfer rates as a function of the widths of the vents, solid/fluid conductivity ratio and Rayleigh number are documented.

A numerical model of an unsteady laminar free convection flow and heat transfer is studied in a cavity that comprises a vertical flexible thin partition.

The left and right vertical boundaries are isothermal, while the horizontal boundaries are insulated. Moreover, the thin partition, placed in the geometric centerline of the enclosure, is considered to be hyper elastic and diathermal. Galerkin finite-element methods, the system of partial differential equations along with the appropriate boundary conditions are transformed to a weak form through the fluid-structure interaction and solved numerically.

The heat transfer characteristics of the enclosure with rigid and flexible partitions are compared. The effect of Rayleigh number and Young’s modulus on the maximum nondimensional stress and final deformed shape of the membrane is addressed.

Incorporation of vertical thin flexible membrane in middle of a cavity has numerous industrial applications, and it could noticeably affect the heat and mass transfer in the enclosure.

The purpose of this paper is to optimize the heat transfer rate in square cavity by attaching fin at the bottom wall.

The problem is formulated and solved using finite element method. Accuracy of the method is validated by comparisons with previously published work.

It was found that attaching fin reduces heat transfer rate in the cavity.

Although the problem is not very original it is important in that many applications have heating on adjacent walls.

The purpose of the present paper is to model a cavity, which is equally divided vertically by a thin, flexible membrane. The membranes are inevitable components of many engineering devices such as distillation systems and fuel cells. In the present study, a cavity which is equally divided vertically by a thin, flexible membrane is model using the fluid–structure interaction (FSI) associated with a moving grid approach.

The cavity is differentially heated by a sinusoidal time-varying temperature on the left vertical wall, while the right vertical wall is cooled isothermally. There is no thermal diffusion from the upper and lower boundaries. The finite-element Galerkin technique with the aid of an arbitrary Lagrangian–Eulerian procedure is followed in the numerical procedure. The governing equations are transformed into non-dimensional forms to generalize the solution.

The effects of four pertinent parameters are investigated, i.e., Rayleigh number (104 = Ra = 107), elasticity modulus (5 × 1012 = E_T = 1016), Prandtl number (0.7 = Pr = 200) and temperature oscillation frequency (2p = f = 240p). The outcomes show that the temperature frequency does not induce a notable effect on the mean values of the Nusselt number and the deformation of the flexible membrane. The convective heat transfer and the stretching of the thin, flexible membrane become higher with a fluid of a higher Prandtl number or with a partition of a lower elasticity modulus.

The authors believe that the modeling of natural convection and heat transfer in a cavity with the deformable membrane and oscillating wall heating is a new subject and the results have not been published elsewhere.

This paper seeks to investigate the effect of a heat conducting vertical partition in an enclosure on natural convection heat transfer and fluid flow using the polynomial‐based differential quadrature (PDQ) method.

The PDQ method with the non‐uniform Chebyshev‐Gauss‐Lobatto grid point distribution given below is used to transform the governing equations into a set of algebraic equations. After numerical discretization, the resulting algebraic equations are solved by the successive over‐relaxation iteration method.

It is found that the average Nusselt number decreases towards a constant value as the partition is distanced from the hot wall towards the middle of the enclosure. Furthermore, with decreasing thermal conductivity ratio, the average Nusselt number first increases and passes a peak point and then begins to decrease. The average heat transfer rate exhibits little dependence on the width of the partition in the range taken into consideration in this study for the thickness of the partition.

This study offers more knowledge on natural convection in partitioned enclosures.

The purpose of this paper is to provide a numerical study of conjugate heat transfer by mixed convection and conduction in a lid-driven enclosure with thick vertical porous layer. The effect of the relevant parameters: Richardson number (Ri=0.1, 1, 10) and thermal conductivity ratio (Rk=0.1, 1, 10, 100) are investigated.

The studied system is a two dimensional lid-driven enclosure with thick vertical porous layer. The left vertical wall of the enclosure is allowed to move in its own plane at a constant velocity. The enclosure is heated from the right vertical wall isothermally. The left and the right vertical walls are isothermal but temperature of the outside of the right vertical wall is higher than that of the left vertical wall. Horizontal walls are insulated. The governing equations are solved by finite volume method and the SIMPLE algorithm.

From the finding results, it is observed that: for the two studied cases, heat transfer rate along the hot wall is a decreasing function of thermal conductivity ratio irrespective of Richardson numbers contrary to the heat transfer rate along the fluid-porous layer interface which is an increasing function of thermal conductivity ratio. At forced convection dominant regime, the difference between heat transfer rate for upward and downward moving wall is insensitive to the thermal conductivity ratio. For downward moving wall, average Nusselt number is higher than that of upward moving wall.

Some applications: building applications, furnace design, nuclear reactors, air solar collectors.

From the bibliographic work and the authors’ knowledge, the conjugate mixed convection in lid-driven partially porous enclosures has not yet been investigated which motivates the present work that represent a continuation of the preceding investigations.

The fluid‐dynamic and heat transfer experimental analysis of a gas turbine internal three‐pass blade cooling channel is presented. The passage is composed of three rectilinear channels joined by two sharp 180 degree turns; moreover, the channel section is trapezoidal instead of rectangular configuration, already analysed in depth in the literature. The trapezoidal section is more representative of the actual geometrical configuration of the blade and, in comparison with the rectangular section, it shows significant aspect ratio and hydraulic diameter variations along the channel. These variations have a strong impact on the flow field and the heat transfer coefficient distributions. The flow analysis experimental results ‐ wall pressure distributions, flow visualisations ‐ are presented and discussed. The heat transfer coefficient distributions, Nusselt enhancement factor, obtained using thermocromic liquid crystals (TLC), have been studied as well. In order to understand the influence of the cooling mass flow rate, a wide range of flow regimes ‐ Reynolds numbers ‐ has been considered.

This paper aims to investigate the fluid structure interaction analysis of conjugate natural convection in a square containing internal solid cylinder and flexible right wall.

The right wall of the cavity is flexible, which can be deformed due to the interaction with the natural convection flow in the cavity. The top and bottom walls of the cavity are insulated while the right wall is cold and the left wall is partially heated. The governing equations for heat, flow and elastic wall, as well as the grid deformation are written in Arbitrary Lagrangian–Eulerian formulation. The governing equations along with their boundary conditions are solved using the finite element method.

The results of the present study show that the presence of the solid cylinder strongly affects the transient solution at the initial times. The natural convection flow changes the shape of the flexible right wall of the cavity into S shape wall due to the interaction of the flow and the structure. It is found that the increase of the flexibility of the right wall increases the average Nusselt number of the hot wall up to 2 per cent.

To the best of the authors' knowledge, the unsteady natural convection in an enclosure having a flexible wall and inner solid cylinder has never been reported before.

An aircraft wing comprises one or more sections each foldablc about a fore‐and‐aft substantially horizontal axis and a power‐operated linearly moving member which works in a guideway and is connected through a link to a foldablc wing section such that with the foldablc section folded the link is substantially at right angles to the movable part so that, aided by the friction of that part with respect to its guide‐way, it prevents self‐return movement of the foldablc wing section. The folding wing section 1 is pivotally attached to the fixed wing stub 6 by brackets 2, 3, the bracket 2 being extended to form a member 7 having pivoted thereto one end of a link 8 the other end of which is pivoted to a rectangular slide 9 located in a straight open‐top guideway 10 carried by the wing section 6. The piston rod 12 of a hydraulic jack 11 is connected to the slide 9. An extension 13 of the wing section 1 is apertured at 13 so positioned with respect to a pair of apertured lugs 14 formed on a bracket 4 secured to the wing section 6 that a preferably power‐operated pin may be inserted therebetween to lock the folded wing in its spread position. When the wing section is folded the link 8 is positioned substantially at right angles to the guideway 10, the axis about which folding takes place being triangulated with respect to the axes of the pins passing through the ends of the link 8 so that return movement of the wing caused by wind gusts is prevented. An additional lock may be provided to hold one or both wings in a partial or fully folded position by providing a plurality of holes in the guideway 10 into any one ofwhich holes a pin may be inserted to prevent return movement of the slide 9. Specifications 635,260 and 635,261 are referred to.

The purpose of this paper is to present a new powder‐based solid freeforming method based on conventional furnace sintering after co‐deposition of mould and part powder materials.

Based on acoustic powder deposition, both mould and part powder materials are delivered simultaneously into the forming area according to the cross section of the 3D computer file. The part is formed in the form of loose powder surrounded by the mould powder again in a loose state. The whole assembly can then be sintered by a conventional method and the mould powder, which has a higher sintering temperature than that of part powder, remains in the loose state after sintering and can be removed.

Complex‐shaped components containing re‐entrant cavities and the capability of being made with 3D functional gradients can be rendered directly as a powder preform suitable for subsequent compaction or direct sintering in a conventional furnace. The flowability and compatibility of the powders need to be selected carefully and the track distance between part/mould powders is important for forming a vertical wall.

The main factors affecting building from powder tracks are identified, including the effect of track distance at an interface on integrity, discontinuous feeding on bends and the effects of fill strategies. The flow rates of the part and mould powder as well as their geometrical maps are controlled computationally. Materials and instrumental aspects are discussed.

This paper describes a method to produce complex‐shaped object without residual stress and expensive lasers and the process could be modified to include 3D functional gradients.