[oj.bulmer]

I work in industry and we use CFD studies to assess the pressure drop characteristics of our products. But lately there is something that is bothering me.

Often clients are interested in the guarantee of the pressure drop values we provide. Now we have done experimental testing of few of our products and typically our CFD results are within 20% of experimental pressure drop values. But then it is not possible to benchmark every product and every size of of that product, and which is the reason CFD is used to fill this gap. But then, I was wondering, if a product of say 6" size is bench-marked with CFD, how to assess whether the same accuracy can be expected in say 30" size of the same product. Or, for that matter any other type of the product.

I have never worked in consultancy, but I am curious to know, if CFD community typically guarantees the results they give for all sizes of the product, based on representative bench-marking done for a single size of the product. Or if the commitment about the accuracy is expected, how it is handled.