Takao Inamura - Academia.edu (original) (raw)

Papers by Takao Inamura

43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2007

Transactions of the Japan Society of Mechanical Engineers Series B, 1999

Heat Pipe Science and Technology, An International Journal, 2015

45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2009

Transactions of the Japan Society of Mechanical Engineers Series B, 2007

Transactions of the Japan Society of Mechanical Engineers Series B, 2008

Transactions of the Japan Society of Mechanical Engineers Series B, 2007

Transactions of the Japan Society of Mechanical Engineers Series B, 2006

Atomization and Sprays, 2004

Aiaa Journal, May 2, 2012

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B, 2013

The Japanese Journal of Thoracic and Cardiovascular Surgery, May 11, 2008

Axillary artery perfusion is an attractive alternative to reduce the frequency of atheroembolism ... more Axillary artery perfusion is an attractive alternative to reduce the frequency of atheroembolism in extensive atherosclerotic aorta and aortic aneurysms. This study was conducted to evaluate the flow dynamics of axillary artery perfusion. Transparent glass models of a normal aortic arch and an aortic arch aneurysm were used to evaluate hydrodynamic properties. Streamline analysis and distribution of the shear stress was evaluated using a particle image velocity method. In the normal aortic arch model, rapid flow of 80 cm/s from the right axillary artery ran out from the brachiocephalic artery and grazed the lesser curvature of the aortic arch. There was secondary reversed flow in the ascending aorta. Flow from left axillary perfusion went straight to the descending aorta. In the aortic arch aneurysm model, flow from both axillary arteries hit the lesser curvature of the aortic arch and went into the ascending aorta with vortical flow. Distribution of shear stress was high along the jet from the ostium of the brachiocephalic artery and left subclavian artery. Flow in the aortic arch and the ascending aorta was unexpectedly rapid. Special care must be taken when the patient has frail atheroma around arch vessels or the lesser curvature of the aortic arch during axillary artery perfusion.

Atomization and Sprays, 2009

Journal of Artificial Organs, 2015

The aim of this study was to evaluate flow from a new dispersive aortic cannula (Stealthflow) in ... more The aim of this study was to evaluate flow from a new dispersive aortic cannula (Stealthflow) in the aortic arch using flow visualization methods. Particle image velocimetry was used to analyze flow dynamics in the mock aortic model. Flow patterns, velocity distribution, and streamlines with different shape cannulas were evaluated in a glass aortic arch model. We compared flow parameters in two different dispersive type cannulas: the Stealthflow and the Soft-flow cannula. A large vortex and regurgitant flow were observed in the aortic arch with both cannulas. With the Stealthflow cannula, a high-velocity area with a maximum velocity of 0.68 m/s appeared on the ostium of the cannula in the longitudinal plane. With the Soft-flow cannula, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;multiple jet streams, each with a velocity less than 0.60 m/s, were observed at the cannula outlet. Regurgitant flow from the cannula to the brachiocephalic artery and to the ascending aorta on the greater curvature was specific to the Soft-flow cannula. The degree of regurgitation on the same site was lower with the Stealthflow cannula than with the Soft-flow cannula. The Stealthflow cannula has similar flow properties to those of the Soft-flow cannula according to glass aortic model analysis. It generates gentle flow in the aortic arch and slow flow around the ostia of the aortic arch vessels. The Stealthflow cannula is as effective as the Soft-flow cannula. Care must be taken when the patient has thick atheromatous plaque or frail atheroma on the lesser curvature of the aortic arch.

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B

ABSTRACT

The International journal of artificial organs

Atheroembolism due to aortic manipulation remains an unsolved problem in surgery for thoracic aor... more Atheroembolism due to aortic manipulation remains an unsolved problem in surgery for thoracic aortic aneurysm. The goal of the present study is to create a computer simulation (CS) model with which to analyze blood flow in the diseased aorta. A three-dimensional glass model of the aortic arch was constructed from CT images of a normal, healthy person and a patient with transverse aortic arch aneurysm. Separately, a CS model of the curved end-hole cannula was created, and flow from the aortic cannula was recreated using a numerical simulation. Comparison of the data obtained by the glass model analyses revealed that the flow velocity and the vector of the flow around the exit of the cannula were similar to that in the CS model. A high-velocity area was observed around the cannula exit in both the glass model and the CS model. The maximum flow velocity was as large as 1.0 m/s at 20 mm from the cannula exit and remained as large as 0.5 to 0.6 m/s within 50 mm of the exit. In the aortic arch aneurysm models, the rapid jet flow from the cannula moved straight toward the lesser curvature of the transverse aortic arch. The locations and intensities of the calculated vortices were slightly different from those obtained for the glass model. The proposed CS method for the analysis of blood flow from the aortic cannulae during extracorporeal circulation can reproduce the flow velocity and flow pattern in the proximal and transverse aortic arches.

International Journal of Multiphase Flow, 2015

ABSTRACT In a high-speed rotary bell-cup atomizer, which is mainly used in the automotive industr... more ABSTRACT In a high-speed rotary bell-cup atomizer, which is mainly used in the automotive industry, atomization is achieved by disintegration of a thin liquid film at the bell-cup edge. To obtain the hydrodynamic behavior of the liquid film as it passes over the bell cup, the liquid-film formation was simulated using the volume of fluid method under various conditions of the rotational speed, flow rate, liquid viscosity, and surface tension coefficient, based on industrial painting conditions. The liquid supplied from the liquid supply nozzle to the bell-cup surface flowed radially upon rotation of the bell cup and formed a film, which reached steady-state. We clarified the flow field depended on the rotational speed, flow rate, and liquid viscosity, and was independent of the surface tension coefficient. Based on these results, an equation for the liquid film thickness was proposed. In addition, the unsteady behavior of film with flow fluctuation in liquid supply was also investigated; the fluctuations persisted at the edge of the bell-cup atomizer. The proposed equation can be applied to this case regardless of the normalized amplitude of the fluctuation up to 50%. Thus, in this condition, unsteady film flow may be described in the proposed equation, which assumes a steady flow.