Industry Standards & Application in Engineering Design Flashcards

In offshore oil and gas engineering, which DNV standard governs the use of CFD for explosion and blast overpressure analysis on topsides?

Answer: DNV-RP-C204

DNV-RP-C204 covers design against accidental loads including explosion blast overpressure, where CFD-based explosion modeling (e.g., FLACS) is widely applied.

According to ASME V&V 20, the 'validation metric' E_val is defined as the difference between:

Answer: Simulation output and experimental data, both with their uncertainties

E_val = S - D, where S is the simulation result and D is the experimental datum, with both quantities carrying their respective uncertainty estimates.

For biomedical device CFD analysis submitted to the FDA, which guidance document outlines the recommended computational modeling and simulation framework?

Answer: FDA Guidance on Reporting of Computational Modeling Studies in Medical Device Submissions

The FDA issued specific guidance on computational modeling (including CFD) in medical device submissions, defining credibility assessment requirements.

In semiconductor cleanroom design per ISO 14644-3, CFD is used to verify which critical airflow parameter?

Answer: Unidirectional airflow uniformity and particle concentration below limits

ISO 14644-3 testing requires verification that cleanrooms achieve specified unidirectional airflow uniformity and particle cleanliness levels, which CFD predicts spatially.

Which element of the CFD uncertainty hierarchy is considered 'aleatory' (irreducible) rather than 'epistemic' (reducible with more information)?

Answer: Turbulent fluctuation randomness in physical flows

Turbulent fluctuations are inherently random physical phenomena (aleatory uncertainty), while discretization, iterative, and round-off errors are reducible with better numerics.

Under NFPA 72 and related fire codes, CFD fire modeling using tools like FDS must demonstrate zone model equivalence primarily to satisfy which design criterion?

Answer: Detector activation time and smoke layer height for egress safety

CFD fire models (FDS) are used in performance-based fire design to predict detector/sprinkler activation times and smoke layer descent to verify safe egress conditions.

The Richardson extrapolation method, recommended in ASME V&V 20 and NASA guidelines, is used in grid convergence studies to estimate:

Answer: The continuum (zero grid spacing) solution value and discretization error order

Richardson extrapolation uses solutions on systematically refined grids to extrapolate the theoretically exact continuum value and estimate the order of discretization error.