PLANING HULL SEAKEEPING IN IRREGULAR HEAD SEAS
UDC 629.5.017/018.71 Summary The paper presents the results of planing hull seakeeping tests in irregular seas. The tested model belongs to a small systematic series developed at the University of Naples; it is a prismatic hull very similar to the well-known Fridsma’s models. The 16.7 degrees deadrise angle, length-to-breadth and load coefficient are representative of modern hull forms of pleasure boats. Tests in irregular waves have been performed at three speeds for one displacement in three sea states. The measured heave, pitch, acceleration at the centre of gravity and at bow have been analysed in the time domain and the results are presented in terms of significant values (the mean of 1/3 rd highest values). They are given in tabular and graphical form. Furthermore, the obtained results are commented with respect to the state of the art in planing hull seakeeping, and compared with the available experimental data from literature. The conclusions highlight the applicability of these data in design practice, commenting on trends and the range of significant parameters.
ADDITIONAL SEAKEEPING MODEL TESTS OF TWO U.S. COAST GUARD NOTIONAL DESIGNS OF 110 FT AND 120 FT WPB HULLS.
The research results presented in this report are concerned with the seakeeping characteristics of two Notional WPB Designs, the 1 1 0 FT WPB and the 120 FT WPB. Model tests of the two hulls were conducted at 10 knots in irregular head seas having significant wave heights of 12.5% of the beam and at speeds from 25 to 70 knots in irregular head seas having a significant wave height of 20% of the beam. Spectral analyses were performed on the motions and accelerations, including the 1/3 octave RMS accelerations. All data were scaled to full size and are tabulated. Planing boat motions, Planing boat performance, WPB Notional hulls, Planing hulls.
Engineering bio-inks for 3D bioprinting cell mechanical microenvironment
Three-dimensional (3D) bioprinting has become a promising approach to construct­ing functional biomimetic tissues for tissue engineering and regenerative medicine. In 3D bioprinting, bio-inks are essential for the construction of cell microenviron­ment, thus affecting the biomimetic design and regenerative efficiency. Mechanical properties are one of the essential aspects of microenvironment, which can be char­acterized by matrix stiffness, viscoelasticity, topography, and dynamic mechanical stimulation. With the recent advances in functional biomaterials, various engineered bio-inks have realized the possibility of engineering cell mechanical microenviron­ment in vivo. In this review, we summarize the critical mechanical cues of cell micro­environments, review the engineered bio-inks while focusing on the selection princi­ples for constructing cell mechanical microenvironments, and discuss the challenges facing this field and the possible solutions for them.