In: Mechanical Engineering
Using the Angström–Page method, calculate the average horizontal
insolation in Hamburg in May and in October with PS 40% and 60%,
respectively.
According to Angström–Page method-


Where 
 and 
 are horizontal terrestrial and horizontal extraterrestrial
radiation levels averaged for a month.
is monthly averaged percent of possible sunshine (i.e. hours of
sunshine / maximum possilble duraiton of sunashine X 100)
a & b are constants for a given site (Table 5.6)
and 
 are monthly average numbers of hours of bright sunshine & day
length, respectively.
The ratio 
/
is also equivalent to monthly average percent sunshine (
).
can be calculated by using below equation-




n= day number starting from January 1 as 1.

Average I for no of days in each month