Understanding Choked Flow Condition for Homogeneous Flow — Lesson 6

This lesson covers the concept of choked flow condition for homogeneous flow. It explains the conditions under which this phenomenon occurs and how it affects the flow rate. The lesson also discusses the significance of the denominator in the homogeneous flow situation and how it corresponds to the Mach number for two-phase flow under homogeneous conditions. It further explains how the two-phase acoustic velocity is not a constant and depends on the composition of the two phases. The lesson concludes with a problem-solving session where the instructor demonstrates how to calculate the pressure gradient and pressure drop in a vertical pipe with a constant heat flux.

Video Highlights

00:17 - Introduction to the concept of chocked flow condition for homogeneous flow
07:37 - Explanation of the significance of the denominator in the homogeneous flow situation
14:13 - Explanation of how to quantify the two phase acoustic velocity
33:45 - Discussion on the conditions under which the two phase acoustic velocity is maximum
39:06 - Explanation of a problem related to pressure gradient and pressure drop in a vertical pipe with constant heat flux

Key Takeaways

- The choked flow condition for homogeneous flow occurs when the flow rate is at its maximum for a given nozzle and stagnation conditions.
- The denominator in the homogeneous flow situation corresponds to the Mach number for two-phase flow under homogeneous conditions.
- The two-phase acoustic velocity is not a constant and depends on the composition of the two phases.
- The maximum acoustic velocity for two-phase homogeneous flow is obtained for a void fraction of 0.5.