Abstract: A method for assembling a composite pressure vessel includes disposing a sealant into each of a plurality of annular slots defined in an exterior surface of a body portion of an end cap. The end cap is aligned with an end portion of a tubular member such that the exterior surface of the body portion of the end cap abuts an interior surface of the tubular member. A force is applied to the tubular member having the end cap aligned with the end portion of the tubular member. The force is applied while rotating the tubular member. The force deforms the tubular member such that the end portion conforms to the plurality of annular slots defined in the body portion of the end cap.

Abstract: A composite pressure vessel assembly method includes fitting an end portion of a tubular member into an annular slot formed in an end cap. Sealant may be in the annular slot. The end cap includes an annular groove in an exterior surface of the end cap body portion. A first material layer is formed on an exterior surface of the tubular member. The first material layer includes a first composite material including fibers oriented circumferentially to the tubular member. A second material layer is formed on the first material layer with a portion of the second material layer being disposed into the annular groove, and includes a second composite material including fibers oriented axially to the tubular member. A third material layer is formed adjacent the second material layer and in the annular groove, and includes a third composite material including fibers having an orientation circumferential to the tubular member.

Abstract: A method for calculating multi-directional composites in FEM simulations for designing a high pressure tank. The method starts by reading data for the simulation including fiber orientation and composite material properties. Then, for every FEM element, the method calculates the stiffness of directional plies and converts the calculated stiffness into a local coordinate system for each ply. The method then calculates the stiffness of packets of fiber orientations as a layer set-up. The method then calculates engineering constants for the layer set-up and the equivalents for the stress limit for the layer set-up. The method then uses the engineering constants to calculate the stresses on the FEM elements and determines whether the calculated stress is above a predetermined stress limit for each element. If the calculated stress is above the stress limit, then the algorithm switches to a complex calculation of stress that calculates the stress for each ply.

Abstract: A composite pressure vessel assembly method includes fitting an end portion of a tubular member into an annular slot formed in an end cap. Sealant may be in the annular slot. The end cap includes an annular groove in an exterior surface of the end cap body portion. A first material layer is formed on an exterior surface of the tubular member. The first material layer includes a first composite material including fibers oriented circumferentially to the tubular member. A second material layer is formed on the first material layer with a portion of the second material layer being disposed into the annular groove, and includes a second composite material including fibers oriented axially to the tubular member. A third material layer is formed adjacent the second material layer and in the annular groove, and includes a third composite material including fibers having an orientation circumferential to the tubular member.

Abstract: A method for calculating multi-directional composites in FEM simulations for designing a high pressure tank. The method starts by reading data for the simulation including fiber orientation and composite material properties. Then, for every FEM element, the method calculates the stiffness of directional plies and converts the calculated stiffness into a local coordinate system for each ply. The method then calculates the stiffness of packets of fiber orientations as a layer set-up. The method then calculates engineering constants for the layer set-up and the equivalents for the stress limit for the layer set-up. The method then uses the engineering constants to calculate the stresses on the FEM elements and determines whether the calculated stress is above a predetermined stress limit for each element. If the calculated stress is above the stress limit, then the algorithm switches to a complex calculation of stress that calculates the stress for each ply.

Abstract: A fuel cell arrangement consisting of several fuel cells, arranged at least essentially in parallel, with cooling gaps formed between neighboring cells extending between an inlet and an outlet and through which a coolant flows, characterized by the fact that the specific surface, i.e. the area of the cooling surfaces emitting heat to the coolant, increases in the direction from the inlet to the outlet and/or that the local heat transfer coefficient of the cooling areas emitting heat to the coolant increases in the direction of flow from the inlet to the outlet and/or that the support materials of the fuel cells, i.e. the membrane-electrode assemblies, exhibit a coefficient of thermal conductivity above 200 W/(m·K). In this way, a uniform temperature in the fuel cells can be assured to that the power density can be increased while avoiding hot spots and/or the service life can be increased.

Abstract: A fuel cell arrangement consisting of several fuel cells, arranged at least essentially in parallel, with cooling gaps formed between neighboring cells extending between an inlet and an outlet and through which a coolant flows, characterized by the fact that the specific surface, i.e. the area of the cooling surfaces emitting heat to the coolant, increases in the direction from the inlet to the outlet and/or that the local heat transfer coefficient of the cooling areas emitting heat to the coolant increases in the direction of flow from the inlet to the outlet and/or that the support materials of the fuel cells, i.e. the membrane-electrode assemblies, exhibit a coefficient of thermal conductivity above 200 W/(m·K). In this way, a uniform temperature in the fuel cells can be assured to that the power density can be increased while avoiding hot spots and/or the service life can be increased.