In experiments we used a model of a cooling tower that had the same geometric proportions as  in  [6 ]. From
the viewpoint of physical criteria,  there was  similarity in  the  Prandtl  number,  since  in  both  cases we used water
for  the  cooling. The Rayteigh number  for  the  laboratory  experiments  lay within  the  range  from  108  to  109. For
actual cooling towers  100 m  in height Ra  -~  1015. Here the following should be noted: for Rayleigh numbers obtained
both  in  a  laboratory installation  and  in  an  actual  cooling tower,  the  flow inside  the  tower is  turbulent  in  character.
This  permits  one  to  extend  the  results  of laboratory modeling  to  actual objects.
Since  under  actual  conditions  cooling  towers  are  exposed  to  the  effect of wind  loading,  then  in  order  to
simulate  the  interaction of an  ascending free convective  flow inside a  tower with  an  external wind we  introduce one
more  similarity parameter
S  =  v/w,  (3)
where  v  is  the  speed  of  the  wind;  w  =  X/2flgATH  is  the  calculated  vertical  velocity  of  free  convective  flow.  In
experiments  the  parameter S  varied within  the  range  from 0  to 2.
The problem of the selection of similarity numbers  to simulate the processes of evaporative cooling in  towers
is much more complex.  In  experimental investigations use was made  of water  and  air as  heat  agents,  as  is  done  in
the majority of actual  towers. Therefore, there was  similarity in  all of the  thermophysical parameters.  To  take  into
account the integral effect of thermodynamic and aerodynamic factors on the process of evaporative cooling of water,
we  shall make  use of certain  results  of  [7 ].
It  is  shown  in  that work  that  the  drop  in  the  temperature of water  in  a  tower ATw depends  on  the  limiting
drop  in  the  temperature  of cooling ATIi  m and  on  the  relationship  between  the mean  mass  flow  rates  of water Qw
and  air Qa  through  the  cross  section of the  tower  in  the  following way:
(Qw)  (4) AT  w=ATlim/  1 +A~  ,
where ATw = TO--  Tf.  Here Ty  is  the  temperature of water  in  the  tank,  T  O  is  the  temperature of water  entering  the
water  distributor;  ATIi  m =  Tlim  -  T  0,  where  Tit  m  is  the  limiting  cooling  temperature  [1 ]  determined  from  the
condition
Ps  (Zlim) = Ps  (Za) ~, (5)
whereps(T)  is  the density of saturated vapors at the given temperature; ~p  is the relative humidity of the surrounding
air.
The  parameter A  in  Eq.  (4)  can  be  determined only  experimentally.  It  is  a  slowly varying  function  that
depends  on  the  character of water  spraying,  the  design  of the water-distributing  system,  and  the  elements  in  the 冷却塔实验室模型英文文献和中文翻译(2):http://www.youerw.com/fanyi/lunwen_6883.html