Empirical correlation for ejector design

In the present study, two empirical correlations from the test results of 15 ejectors are derived for the performance prediction of ejectors using R141b as the working fluid. The ratio of the hypothetical throat area of the entrained flow to the nozzle throat area A(e)/A(t), the geometric design parameter of the ejector A(3)/A(t), and the pressure ratios P-g/P-e and P-c*/P-e are used to correlate the performance of the ejector. The prediction of the entrainment ratio omega using the correlations is within +/- 10% error. A method of calculation for the ejector design using the correlations is also developed. R141b is shown in the present study to be a good working fluid for an ejector. The measured omega for the ejectors used in the present study can reach as high as 0.54 at P-g = 0.465 MPa (84 degrees C), P-c* = 0.087 MPa (28 degrees C) and P-e = 0.040 MPa (8 degrees C). For P-g = 0.538 MPa (90 degrees C), P-c* = 0.101 MPa (32 degrees C) and P-e = 0.040 MPa (8 degrees C), omega reaches 0.45. (C) 1999 Elsevier Science Ltd and IIR. All rights reserved.