| Project/Area Number |
05650185
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | YONAGO NATIONAL COLLEGE OF TECHNOLOGY |
|---|
Principal Investigator |
SUMIDA Masaru YONAGO NATIONAL COLLEGE OF TECHNOLOGY., DEPT.MECH.ENGR., ASSOCI.PROF., 機械工学科, 助教授 (60113403)
|
|---|
| Project Period (FY) |
1993 – 1994
|
| Project Status |
Completed (Fiscal Year 1994)
|
| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Keywords | PULSATING FLOW / AORTA / CURVED PIPE / OSCILLATING FLOW / VELOCITY DISTRIBUTION / ENTRANCE REGION / 非定常流 / 二次流れ |
|---|
| Research Abstract |
The blood flow in the aorta is a complex periodic flow that includes high frequency components. In this aortic arch circulatory faults occur frequently. Thus dealing with fluid dynamics has been of great importance even in our society today. In order to reveal the nature of flow development in the aorta, it is necessary to analyze the flow in curved pipes. The purpose of this project is to solve the problem of the oscillating and pulsating flows in the inlet region of curved pipes modelled on the aorta. By flow visualization method and LDV measurement, the following velocity distribution results were obtained.
1. On the oscillating flow. The flow in the curved pipe is closely related to the flow in the upper stream tangent, and the velocity distribution changes drastically with the phase at the inlet region. The inlet length of the oscillating flow is less than that of the steady flow and becomes shorter as the Womersley number alpha increases.
2. On the pulsating flow. The velocity distributions change rapidly with the phase at OMEGA=15-35ﾟ around the curved turn. The flow phenomena occurring in the entrance region of the curved pipes are too much complicated for an intermediate Womersley number alpha=10. The flow reversal occurs in the inner half cross-section of the curved pipe with OMEGA*15ﾟ and at phases with minimum flow rate for all values of alpha. And the depression in the axial velocity profile appears after the fouhth round in the curved pipe for alpha=10. The inlet length of pulsating flow is less than that of steady flow with the same flow rate as the maximum one in pulsating flow.
|
