Cooling static loading

This paper discusses the impact of wind action on natural-draft cooling towers. The structure of the wind load may be divided into a static, a quasistatic, and a resonant part. The effect of surface roughness of the shell and of wind profile on the static load is discussed. The quasistatic load may be described by the variance of the pressure fluctuations and their circumferential and meridional correlations. The high-frequency end of the pressure spectra and of the coherence functions are used for the analysis of the resonant response. It is shown that the resonant response is small even for very high towers, however, it increases linearly with wind velocity. Equivalent static loads may be defined using appropriate gust-response factors. These loads produce an approximation of the behavior of the structure and in general are accurate. 11 refs, cited. 

The volume includes 37 papers. Discussions cover the verification of flat plate analyses by model studies long-term behavior of small composite prestressed concrete bridge beams studies of a prestressed concrete girder with web openings the structural behavior of a hyperbolic cooling tower under static loadings models of shear wall structures ... 

A dynamic statistical approach is used to predict dynamic stresses in a hyperboloidal cooling tower due to earthquakes. It is shown that the configuration associated with one circumferential wave is the only one which is excitable by earthquake force and that the first mode of such configuration is dominant. An equivalent static load is calculated on this basis. Numerical data presented give coefficients for equivalent static loads, natural frequencies of cooling towers, and static stresses for a seismic load. 21 refs, cited. 

A single craze is produced at a running crack-tip in PMMA at 20 °C (or perhaps at any temperature from —25 to 70 °C), at a l.Opm/s velocity, under static loading. The craze is kept stretched and cooled to —25 °C to freeze-in any subsequent relaxation. The load-thickness curve of that craze is measured at 11 Hz. 

Static loads encompass heaters, battery chargers, uninterruptible power supplies, lighting distribution boards, socket outlets, cathodic protection, navigational aids, computers, public address, radio communication and the like. Excluded are loads that are not predominantly composed of motors. The load may have fractional kW motors for cooling fans. 

A characteristic feature of the PEACER-300 is the reactor vessel auxiliary cooling system (RVACS). Figure XXIV-18 presents the schematic diagram of this system. For a reactor with an RVACS-type decay heat removal system with liquid Pb-Bi in the gap between the reactor vessel and the guard vessel, the static load is accommodated by the guard vessel, because the reactor vessel floats in the liquid Pb-Bi. 

The equilibrium equations of a hyperboloid of revolution used for cooling towers derived by using membrane theory under an arbitrary static normal load are reduced to a single partial differential equation with constant coefficients. The problem of finding displacements is reduced to a similar type of equation so that the solution for this problem becomes straightforward. 11 refs, cited. 

An important part of the design process is the simulation of the performance of a designed device. As an example a fastener or snap-fit is designed to work under certain static or dynamic loads (Chapter 4). The temperature distribution in an electronic chip may need to be calculated to determine the heat transfer behavior and possible thermal stress. Turbulent flow over a turbine blade controls cooling but may induce vibration. Whatever the device being designed, there are many possible influences on the device s performance. 

A preliminary modelling analysis involved the parametric study of a multi-tubular externally-cooled fixed-bed reactor for a generic selective oxidation process, where the catalyst load consisted of cylindrical honeycomb monoliths with washcoated square chaimels, made of highly conductive supports. In this early work, the attention was focused on the effect of catalyst design. Simulation results were generated by a steady-state, pseudo-continuous 2D monolithic reactor model, where the catalyst is regarded as a continuum consisting of a static, thermally connected solid phase... 

The flow resistance of the mixer can impose excessive stresses on the mixer itself. Following element folding, in an angled plate static mixer where the welded elements proved unable to withstand the loads applied in a melt cooling application, it was replaced by a single piece element machined from a solid steel blank. This proved suitable for the task (Figure 11.5). 

The reactor core and associated internal components located within the reactor vessel shall be designed and mounted in such a way that they will withstand the static and dynamic loading expected in operational states, design basis accidents and external events to the extent necessary to ensure safe shutdown of the reactor, to maintain the reactor subcritical and to ensme cooling of the core. 

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