Exam1_SOLUTIONS - ENU 4134 – Exam#1 – Fall 2011 –...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ENU 4134 – Exam #1 – Fall 2011 – NAME: SOLUTION SET 1 1. Two-Phase Transport Equations (20 points) (a) The 1-D mixture momentum transport equation for includes 5 terms; reprinted below assuming A z is constant in z . Briefly (couple-few words) explain the physical significance of each term (3 points each, 15 total). ∂ ∂t [ G m ] + g cos( θ ) ρ m + ∂ ∂z [ p ] + F 000 wz = ∂ ∂z " G 2 m ρ + m # (1) Transient term, gravity term, pressure (gradient term), forces at fixed bound- aries term [interface(s) wall(s) force(s) ok], convective term (b) Why do no F 000 sz terms appear in this equation (5 points)? These inter-phase interface terms cancel out in derivation of the mixture equation. Not linked to phase change; cannot declare equal to zero without justification. 2. Flow Regimes and Regime-Specific Phenomena (24 points) (a) What does the acronym IATE stand for in two-phase flow modeling? (4 points) Interfacial area transport equation – 1 per word (b) In annular flow, the triangular relationship asserts that given any 2 (of 3) parameters, the 3rd can be computed. What are these 3 parameters? (6 points) Film thickness, film flow rate (or entrained fraction) [“film flow velocity” - 1/2], interfacial shear (or pressure gradient – wall shear tolerated) (c) Fill-in-the-blank (14 points total, 2 per blank): • The IATE is most frequently used in bubbly (bubbly/annular) flows. • In annular flow, most droplets are thrown from waves (waves/base film/the right fielder). • The wavy-annular regime is observed in horizontal flow (horizontal flow/vertical upflow/vertical downflow). • The transition from counter-current (gas upward, liquid downward) to mixed up- ward/downward liquid flow is termed flooding (flow reversal/flooding) • The cap-bubbly regime exists for flow areas with very large (large/small/asymmetric) hydraulic diameters only....
View Full Document

{[ snackBarMessage ]}

Page1 / 8

Exam1_SOLUTIONS - ENU 4134 – Exam#1 – Fall 2011 –...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online