Aspects of the study of heat dissipation using models

The Author had been engaged on a model study of the dissipation and the possible recirculation of heated water which was to be discharged from the circulating water system of a steam power station sited on a tidal river, He has described this investigation in a paper "A hydraulic model study of heat dissipation at Kincardine power station". It seemed that further work on the basis of design of such models would be worth while and that the various modes of flow involved might be examined for scale effects in isolation (1). Various aspects of small density difference phenomena which affect free surface hydraulics are reviewed (2), together with the present status of model simulation of these phenomena (3). In describing the circuit of flume and tank which was built for the studies, the general requirements for apparatus for small density difference studies are discussed (4). A thermopile recording system was chosen from the various possible means of indicating the mixing and dilution of introduced water, and the construction (5), use (8) (9) and possible development (13) of the indicating probes is described. This system is thought to be very suitable for any future ad hoc or basic studies. The first mode of flow to be studied was the pure density current exchange flow as found in idealised lock experiments. Some additional information on the overall characteristics of the overflow was obtained, and a scale effect, caused by small variations in surface tension, was noted. This easily obviated phenomena might seriously impair similarity in heat dissipation models. It was found that the requirements for similarity in lock experiments are applicable to internal gravitational advance in open water, and some success was achieved in the simulation of small scale prototype phenomena in very small scale models (7) (9). Vertical mixing was studied using the recording apparatus and the applicability of the general Froude model law was confirmed (8). Modified forms of lock flow are suggested as being pertinent to the spread of less dense water over more dense water, when both are combined as an external gravitational current (1O). The effect of heat losses on model simulation is considered (11) and the economics of heat dissipation are reviewed in some detail (12) After summarising, the possible form of future ad hoc studies is discussed and recommendations made for future basic studies (13). A comprehensive list of references (14), the tables and figures collected at the start of the second volume (15), the test recordings (16) and the notation (17) follow. A subsidiary outfall scour model had been run in conjunction with the main Kincardine model and this also left some uncertainties which were partially elucidated in a series of tests described in an appendix (18). In a further appendix, some minor aspects of the Kincardine investigation are discussed (19)