"For the metal segment of the intake runners, 6061-T6 was chosen as the primary material of choice as it easy to fabricate the tubing to the proper inner and outer diameters. Machining of the injectors via traditional methods is also more practical compared to with steel. The second material of choice was 17-4 PH Stainless Steel. Although not the most popular variant of steel, this material can be 3D printed on any standard FDM 3D printer. At a material price of just $116.10/kg, the desired geometry can be printed and then shipped out for debinding and sintering. The 3D-printed segment of the runners as well as the plenum, cannot be printed out of metal due to dimensional constraints related to the sintering process. Traditional manufacturing methods are not possible for the desired geometry of the intake system. Composite layup is possible, but not feasible on the current timescale of the project. Due to these factors, two standard 3D printing filaments have been chosen. A popular material amongst Formula SAE and Formula Student teams for the intake system is NylonX. This material is composed of a roughly 80% Nylon, 20% Carbon Fiber mixture that gives it incredibly high tensile strength, and good heat resistance, all at a low cost compared to metal options. A second and more budget-minded option was tested in ASA filament. This material is comparable to ABS in that it exhibits a brittle, high tensile strength relative to other plastics. The major difference to ABS is its superior resistance to the environment long-term, and its oftentimes slightly higher temperature resistance. Finally, for the restrictor, ABS was chosen as the primary material. The factor of safety of the restrictor should be lower than all other parts, as this is the easiest part to produce and replace. ASA was chosen as the second option for the restrictor. Both of these materials can be chemically melted with Acetone. By melting with Acetone, the surface roughness of the material can be
significantly reduced. The tensile strength for the metals 6061-T6 Aluminum and 17-4 PH Stainless steel were
40000 psi and 16679.3 psi. Meanwhile, for NylonX, ABS, and ASA, the tensile strengths were 14503.8 psi, 6236.6 psi, and 6352.6 psi, respectively.

VALIDATION METHODOLOGY

For the metal runners, plenum combination, and restrictor, the maximum deflection was calculated to be compared to ANSYS results. The elastic modulus and arc length of the curve was used in tandem with the peak pressure of the wave or manifold air pressure (MAP) to estimate the deformation. This equation was chosen due to its ability to be applied universally over all geometries given the assumption that any deformation was nonpermanent.
𝜎 = 𝐸𝜖
𝜎 = 𝐸 * (𝛿/L)
𝛿 =(𝐿𝜎)/𝐸

FINITE ELEMENT METHODOLOGY

For all components analyzed, tetrahedrons were used as the hex dominant method could not generate a proper for the geometries. All parts were also simulated under 2G’s of deceleration, as the suspension sub team has reported this to be the maximum acceleration/deceleration that will occur. All bolting surfaces underwent 15 lbs. of force to simulate being bolted into place. And as previously mentioned, all parts underwent two loading scenarios: standard operating conditions under 20 psi of vacuum internally, and a pressure wave reaching a peak of 60 psi of positive
pressure, or as it is called frequently in automotive circles, “boost”.

For the printed segment of the intake runners, as well as the plenum, a body sizing of 0.495 inches was chosen for each element due to both computational cost and license limits. Next, a face sizing of 0.25 inches was set for the mating bracket between the plastic and metal intake runners. This was done to remedy a meshing error in which the aforementioned face was considered too undetailed for ANSYS to generate a mesh for the entire body. Afterwards, a
refinement of 1 was done along the edges where the pressure-relief system is located in the part. Next, a refinement of 1 was placed on the inner face of the plenum where the most acute angle occurred. Lastly, a refinement was added to the outer and inner edges of the plenum near the blow-off valve system. This component was fixed about the flange and the plenum to restrictor mating surface."