What is the relationship between time and heat transfer coefficient? Actually are there any at all? What happens to time taken in heat transfer if the coefficient is value is raised or lowered?
All we know is $$Q=hA(T-T_a)$$ which does not include time. Only surface area and temperatures. Let us say a casting takes 40 minutes to cool down to its 95% of the original temperature. Now if the heat transfer coefficient is 5 times higher, what will be the time required? Will it still take 40 minutes to cool down to 95% of the original temperature?