To evaluate theinfluence of dof on manoeuvring predictions by direct CFD zig-zag simulations

In this paper, direct CFD zig-zag simulations of 10°/10° and 20°/20° are performed in deep water condition under the consideration of different degrees of freedom, namely 3 DOF, 4 DOF, and 6 DOF, to evaluate their influence on manoeuvring predictions. A modern container ship KCS with a slightly simplified semi-balanced rudder is chosen as the benchmark model. All simulations are conducted in the numerical environment FINETM/Marine with the ISIS-CFD code as the flow solver. It solves impressible unsteady RANS equations in full hexahedral unstructured meshes and implicitly couples the flow field with motion equations of a rigid body in 6 DOF. Current direct manoeuvring simulations are achieved by means of the overlapping grid technique. To reduce the computational effort, propeller effect is modelled by a simple prescribed body force model. Trajectories are straightforward recorded without any further treatment to extract hydrodynamic derivatives. The prediction accuracy is evaluated by comparing derived parameters, i.e. overshoot angles and times, peak yaw rates, drift angles, etc. against experimental data. In conclusion, 4 DOF and 6 DOF concept present similar results for current ship type. The tiny changes in pitch and heave motion indicate they can be neglectable to simplify the complex mesh strategy. In addition, the large roll angle over zig-zag manoeuvres implies that 4 DOF concept should be more reasonable for container ships to obtain roll-motion-related data. Meanwhile, 3 DOF concept underestimates all overshoot angles in each simulation. This also highlights the reasonability of 4 DOF concept

The Effect of Lyso-PAF on Ciliary Activity of Human Paranasal Sinus Mucosa in vitro

The effect of lyso-PAF on ciliated cells was investigated in vitro. Normal mucosa was surgically obtained from human paranasal sinuses and incubated in the form of tissue culture. Ciliated epithelium was magnified under an inverted microscope, and ciliary movement was photo-electrically measured. Ciliary activity was significantly inhibited by 10−8 M lyso-PAF and could be restored. The effect of lyso-PAF was completely blocked by CV-6209, a specific PAF antagonist. The PAF concentration in the incubation medium of lyso-PAF was determined by radioimmunoassay, because PAF is a well known inhibitor of ciliary activity. PAF gradually increased and after 20 min reached its maximal level. These findings indicated the existence of an enzyme in the paranasal sinus mucosa, by which lyso-PAF is converted to PAF, and that lyso-PAF can inhibit ciliary activity by means of PAF

Elevation of soluble interleukin-2 receptor levels in nasal allergy

To investigate soluble IL-2 receptor (sIL-2R) levels in nasal allergy, the sera and nasal secretions from patients with nasal allergy and from healthy subjects were subjected to a double-epitope enzyme-linked immunosorbent assay. Significant elevation of sIL-2R concentrations in the sera and nasal secretions was observed in the allergy patients (n = 26) compared with those of healthy subjects (n = 9). IL-2R-positive (CD25+) cells were observed in the crust formed in an allergic nasal mucosa. The concentration of sIL-2R in the sera correlated neither with the eosinophil count of the peripheral blood count nor with clinical severity. The concentration of sIL-2R in the nasal secretions was significantly higher compared with that in the sera from allergic patients (p < 0.01), whereas no significant difference was observed between sIL-2R levels in the sera and nasal sections from normal subjects. These findings indicate that sIL-2R plays an essential role in allergic processes by regulating IL-2R-positive cells recruited into the nasal mucosa

CFD Simulation of PMM Motion in Shallow Water for the DTC Container Ship

International audienceThis paper is devoted to the validation exercises with the ISIS-CFD code conducted for the test cases proposed for the MASHCON conference. CFD simulations have been performed for the 4 different pure yaw and pure sway test cases under shallow water condition. Predicted results are compared with the measurement data provided by FHR

Detection of soluble interleukin-2 receptor and soluble intercellular adhesion molecule-1 in the effusion of otitis media with effusion

We measured sIL-2R, TNF-α and sICAM-1 in the sera and middle ear effusions (MEEs) of patients with otitis media with effusion (OME). Although there was no signmcant difference between the sIL-2R levels of the serous and mucoid MEEs, they were significantly higher than serum sIL-2R levels of OME patients and healthy controls. TNF-α levels of the mucoid MEEs were significantly higher than those of the serous type. However, TNF-α was rarely detected in the sera of OME patients or healthy controls. We observed significant differences between the serous and mucoid MEEs with respect to their sICAM-1 levels, which were also higher than serum slCAM-1 levels of OME patients and healthy controls. Our findings suggested that IL-2, TNF-α and ICAM-1 could be significantly involved in the pathogenesis of OME through the cytokine network

Towards automated computation with uncertainty estimation for industrial simulation of ship flow

Adaptive grid refinement is tested for routine, automated simulations of ship resistance in calm water. A simulation protocol for these computations is fine-tuned on one test case and then applied unchanged to three different cases. The solutions are numerically accurate and compare well with experiments. Effective numerical uncertainty estimation increases the trustworthiness of the solutions

Divergence-Free Extended Hybridizable Discontinuous Galerkin Method (X-HDG) For Laminar Incompressible Two-Phase Flow

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The Role of Bookkeeping for Regional Promotion and Agriculuture －From the Viewpoint of New Classified Models on Japanese Farmers－

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