Template:Demo AC BPA

From QNET
Jump to navigation Jump to search

The Best Practice Advice (BPA) for Application Challenges (ACs) follows the same format as that adopted for UFR BPA . However, the advice should concentrate on the prediction of the design or assessment parameters (DOAPs) since, by definition, these are the quantities of prime interest to the analyst. This does not preclude consideration of the detailed flow structure (i.e higher order parameters) if this is both possible and deemed to add value to the advice. The BPA should constitute a synthesis of the data contained within this AC document with that in the associated UFRs (as formalised in the UFR BPAs ). Guidance on how to make this synthesis is set out below. It is important to stress that the advice set down should be supported by the evidence presented in these documents. Personal prejudice and judgements based on personal experience must be avoided.


The DOAPs may not be well predicted in the AC study because the UFR-BPA, based on strong high quality evidence, has not been followed in the AC calculations (e.g. insufficient grid, low order numerical scheme, incompetent turbulence models etc.). Under such circumstances the AC-BPA advice should be based upon the UFR-BPA and appropriate recommendations made for further AC studies.

The evidence embodied within the AC-Document may not be consistent with the associated UFR-BPA. There may be various reasons for this:

  1. There are no UFRs presently within the knowledge base which are relevant to this AC.

  2. The UFR test cases which have been studied are not sufficiently well aligned with the flow conditions encountered in the AC. For example the flow parameters/conditions controlling the UFR test-case may not be as severe as the AC case (e.g. pressure gradient, level of streamline curvature, Grashof number etc.), or perhaps the UFR test case features several interacting flow regimes of which only one is relevant to the AC.


Under such conditions, you should base the BPA solely on the AC evidence (provided this is of sufficient detail and quality) and then make appropriate recommendations for the identification and analysis of UFR test cases.

The reasons for the (marked) inconsistency may be none of the above and may not be easily identifiable. The inconsistency could be due to AC application uncertainties. Once again, under such circumstances you should base your AC-BPA solely on the AC evidence (providing this is of sufficient detail and quality) whilst embodying appropriate caveats.

If, in the last analysis, the detail and quality of the AC data is not sufficient for drawing out reasonably well-founded BPA, then this should be stated, the BPA left open, and recommendations made for further remedial work.