b'Marine | Engineer InnovationModern cruise liners are often calledfeatures developed by STX France in floating hotels featuring luxurytheir ECORIZON program.cabins, a wide range of shopping, dining and entertainment areas, andAs part of their drive to create the innovative outdoor swimming andmost energy-efficient and leisure areas. With all of thesecomfortable, best-in-class ships, STX amenities, passengers expect aFrance is increasing its use of luxurious experience. The largestcomputational fluid dynamics (CFD) cruise ships can accommodate up toas part of the design process. CFD has 6,000 passengers and 2,000 staff, thebeen used systematically for more equivalent of a small town floating onthan ten years to optimize hull the ocean. geometries and ship-wave interactions. More recently, STX While passengers relax and enjoy theFrance has started using CFD as a tool various on-ship options, manyto predict exhaust plume dispersion in services are working behind thethe vicinity of the superstructure. This scenes; these include diesel enginesmethod has allowed them to powering the liner, kitchens supplyingunderstand the plume behavior in the food to restaurants, as well asdetail and improve the design of laundry services and incinerators. Anfunnels and vents to avoid fumes in unfortunate by-product of thesethe passenger decks. STX is using systems are exhaust fumes, whichSimcenter STAR-CCM+TM software.have to be vented to the outside of the ship. If these fumes drift backShip plumes onto the ship, they can create smellGases are vented from the ship at discomfort for both passengers anddifferent locations; the exhaust gases crew. Any area of the ship withare generally warmer than the unpleasant odors will be avoided orsurrounding air so they rise in a unusable by passengers. The humanplume away from the vent. The sense of smell is so sensitive thatdevelopment of this plume is highly even concentrations as low as 300dependent on the environmental parts per million of diesel fumes willconditions. Cruise ships run at an make passengers uncomfortable. Shipaverage speed of 20 knots, while the owners want to avoid any discomfortprevailing wind direction can vary in or wasted/dead space, but also wantboth strength and direction. The to maintain the overall aesthetic andspeed of the exhaust gases at the design of the ship.vent is generally low compared to the external flow, so the plume motion STX France has extensive experienceand development is turbulent and designing and building cruise ships tohighly unsteady. A typical Gaussian meet the highest requirements andplume model will not correctly standards, and has delivered manycapture the development of the vessels operating all over the world.plume, as it neglects the crosswind STX France is proud of its heritage ofcontribution to the flow. Instead, it is more than 100 years of shipbuildingbetter to think of the plume as a and of its ability to innovate andseries of puffs, or highly unsteady create the ultimate luxury experience.winds moving in three dimensions Deliveries include Harmony of theand growing and dispersing over Seasone of the largest cruise shiptime.ever builtwhich recently received the fuel efficiency award at thePlume modeling Seatrade exhibition. TheTo examine the plume dispersion in Mediterranean Shipping CompanySimcenter STAR-CCM+, STX France (MSC) Meraviglia cruise ship makesmodels the entire superstructure of use of all the latest environmentalthe ship. Each ship has a different 19'