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The aim of this paper is to investigate the conjugate forced convection in a semi-cylindrical cavity with air flow. Isotherms, streamlines, Bejan number and local entropy generation number are obtained for the semi-cylindrical cavity. Local Nusselt number, the temperature and the skin friction along the interface wall are calculated with different Reynolds numbers and geometric configurations.

The governing differential equations discretized by finite volume method are solved using SIMPLE algorithm. In this study, collocated grid, where all flow variables are stored at the same location, is used. Alternating direction implicit method and tri-diagonal matrix algorithm are used to solve linear algebraic equation systems.

The effects of Reynolds numbers, inlet and exit cross-section, the locations of exit section on fluid flow are also numerically investigated. It has been observed that since the secondary vortices developed near the exit cross-section negatively affect heat transfer, the temperature value is higher at this region. Better cooling inside cavity is provided in the cases of higher Re number, larger inlet and exit cross-section. The minimum average Nu numbers are computed for the location of L = 0.40 and the minimum total entropy generation numbers are founded in the case of L = 0.20.

This study provides insight into proper cooling and entropy generation inside the semi-cylindrical cavity for different conditions.

The purpose of this study is to numerically investigate heat transfer and entropy generation between airframe and cabin-cargo departments in an aircraft. The conjugate forced convection and entropy generation in a cylindrical cavity within air channel partly filled with porous insulation material as simplified geometry for airframe and cabin-cargo departments are considered under local thermal non-equilibrium condition.

The non-dimensional governing equations for fluid and porous media discretized by finite volume method are solved using the SIMPLE algorithm with pressure and velocity correction.

The effects of the following parameters on the problem are investigated; Reynolds number, Darcy number, the size of inlet and exit cross-section, thermal conductivity ratio for solid and fluid phases, angle between the vertical symmetry axis and the end of channel wall exit and the gap between adiabatic channel wall and horizontal adiabatic wall separating cabin and cargo sections.

This paper can provide a basic perspective and framework for thermal design between the fuselage and cabin-cargo sections. The minimum total entropy generation number is calculated for various Reynolds numbers and thermal conductivity ratios. It is observed that the channel wall temperature increases for high Reynolds number, low Darcy number, narrower exit cross-section and wider the gap between channel wall and horizontal.

The purpose of this study is to numerically analyze the mixed convection and entropy generation in an annulus with a rotating heated inner cylinder for single-wall carbon nanotube (SWCNT)–water nanofluid flow using local thermal nonequilibrium (LTNE) model. An examination of the system behavior is presented considering the heat-generating solid phase inside the porous layer partly filled at the inner surface of the outer cylinder.

The discretized governing equations for nanofluid and porous layer by means of the finite volume method are solved by using the SIMPLE algorithm.

It is found that the buoyancy force and rotational effect have an important impact on the change of the strength of streamlines and isotherms for nanofluid flow. The minimum average Nusselt number on the inner cylinder is obtained at Ra$_E$ = 10$^4$, and the minimum total entropy generation is found at Re = 400 for given parameters. The entropy generation minimization is determined in case of different nanoparticle volume fractions. It is observed that at the same external Rayleigh numbers, the LTNE condition obtained with internal heat generation is very different from that without heat generation.

To the best of the authors’ knowledge, there is no previous paper presenting mixed convection and entropy generation of SWCNT–water nanofluid in a porous annulus under LTNE condition. The addition of nanoparticles to based fluid leads to a decrease in the value of minimum total entropy generation. Thus, using nanofluid has a significant role in the thermal design and optimization of heat transfer applications.

In an aeroplane, a plurality of flaps to be moved through a range of positions, a reversible flap actuating motor for each flap, a pilot moved control member, a follow‐up member moved by one of said flaps only, a pair of direction switches co‐operating with said members and with said actuating motors to actuate said motors by movement of said control member to move said flaps to positions directly related to the amount of movement of said control member, a limit switch positioned at each flap to be opened only when its respective flap is in a predetermined position, said predetermined position being at one extremity of said range of positions just short of the position normally called for by one of said direction switches at one end position of said control member, said limit switches being connected in parallel with each other and in series with said one direction switch to open said series circuit while said one direction switch is still closed, whereby all of said flaps will reach said predetermined position before said flap actuating motors are de‐energized, a pointer attached to said follow‐up member, and calibrated scale means associated with said control member and said pointer to indicate the actual position of the flap connected to said follow‐up member at all times.

The purpose of this paper is to investigate the aerodynamics characteristics (especially the side force/moment and rolling characteristics), to analyze the impacts generated by different parameters of wrap-around fins (WAFs) and to find the corresponding mechanism.

The paper has adopted three different types of WAFs for the rocket configurations and the sub-regions divided technology to investigate the lateral and rolling characteristics of WAFs, including the fins with variations in span to chord ratio, thickness, leading-edge sweep, curvature radius, fin numbers, setting angles and rotated angles. Simulations have been performed at Mach numbers from 3 to 4 through an angle-of-attack range of about 0° to 10° and at model rolling angles of 45° to 90°.

The paper shows that the WAF configurations can greatly improve the longitudinal stability and enhance the longitudinal aerodynamic characteristics for the whole rocket. The total drag of the whole rocket is mainly stemmed from the body, while the drag generated by the WAF account for only about 7.42 per cent. The extra side forces and rolling moments are due largely to the unequal pressure distributions on both sides of the fin (windward or leeward). Maintaining a certain negative setting angle (d) can effectively avoid the coning movement and improve the flight stability at high angles of attack. The size of the span and chord are two main factors in controlling the longitudinal characteristics. For the side force/moment and rolling characteristics, different geometric parameters of the WAFs have played different roles.

The paper provides the qualitative and quantitative analysis for different WAFs configurations by investigating the curves of different parameters and contouring of static pressure distributions. Findings can provide some suggestions for the designers for avoiding some significant dynamic problems, such as Magnus instability and roll rate variations during flight.

THE eleventh annual meeting of the Institute was for the first time held simultaneously in three centres—in New York City at Columbia University, in Detroit at Rackham Educational Memorial, and in Los Angeles at the University of Southern California—from January 25 to 29. The purpose of the three simultaneous meetings was to minimize travel by executives and engineers from important war jobs in the present emergency. The same programme was offered at all three centres, papers being sometimes presented by proxies—experts in the same field as far as possible. In spite of the fact that attendance was divided between three centres, there was splendid representation at each place and a wide range of subjects was covered in the many papers. Naturally these were restricted more to analysis, and technology and information as to the latest design or production features of current aircraft or engines was withheld. The same ban applied to striking developments in accessories, instruments and armaments. All papers had to be approved by the Army or Navy and to be read substantially as written. While off‐the‐record discussions were permitted, these discussions were not made public. In particular there was a ban on comparisons between foreign and American materials, equipment or methods. The formula for control of comparison performance stated that the manufacturer's smooth curve calibrations and performance figures might be quoted, but no Wright field performance figures or data could be revealed. In spite of such restrictions a tremendous amount of valuable technical information was presented to the assembled engineers.