Solid-Fuel Rocket Motor Efficiency Improvement Scheme - Novel Combustion Concepts for Sustainable Energy Development - page 526

Fig. 1 Flow geometry

Since the cost of experimental testing is very high, due to high temperature and
pressure, research in SRM

field is more focused on numerical simulation. However,
before simulation result could be used in SRM research, CFD model validation is
necessary. To provide validation for CFD modeling, a water - air two-phase straight

channel low with controlled low temperature and pressure is used. In this chapter,

two major parts will be covered, which include the comparison between water

fl

- air

straight channel experiment and CFD results, and a quanti cation method for both

experimental and CFD results is presented.

2 Dimension of Experiment and Simulation

The two-phase flow experiment and simulation were conducted using a rectangular

channel for comparison basis and is shown in Fig. 1 with the dimensions included.
The inlet velocity of water is maintained at 0.68 m/s with air inlet velocity ranging
incrementally from 0 to 40 m/s. The experiment and simulation were performed at
standard room conditions.
A rectangular, transparent acrylic channel was used to simulate the two-
dimensional SRM combustion

fl

fl ow.

3 Physics Equations

The Reynolds ' number is a dimensionless quantity used to predict fl ow patterns.

Using the standard Reynolds for a rectangular duct de ned as, Re = ˁ VD h / ,asa

µ

basis for de ning a Reynolds number for the two-phase rectangular duct fl ow.

Where fluid density, velocity, hydraulic diameter, and

dynamic viscosity, respectively. Since it is advantageous to know the

ˁ , V, D h , and µ are the fl

fl flow condi-

tions that lead to breakup of the liquid fl flow, the velocity term is de ned as the

relative mean velocity as shown in Eq. ( 1 ).