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Nose Intake

Nose Intake

Project Overview

This project entails the creation of two mirrored nose air intakes at the front of the vehicle. These intakes will be epoxied onto the aeroshell. A pair for 4in. aluminum ducts will attach to the intakes and lead to the rear of the vehicle to the radiator. The nose intakes will be designed with modularity in mind and will be rigorously simulated on ANSYS CFD to create an optimized design to intake as much air as possible. Matthew Murzaku and aerodynamics will teach you CFD !!!

Project Owner: @Ava Schraeder

 

Resources:
Current Daybreak Intake (Kaden Freshman Project) → https://pdm.getbild.com/1a8bfccc-0296-4ebc-a5f9-afbca199cf7f/branch/main/file/704e3f81-1c49-4a0f-b3e6-93963a57b744?dir=c486c74a-eda0-4617-99bc-6baeea0610b1

 

Mechanical Partner

The following are the systems and projects you’ll be working with or could have interferences with.

Aerodynamics System → Nose Intake Aeroshell Hole Project

Body System → Ergonomics Subsystem → Front Ballast Box Project

Mechanical POCs:

  • @Harshit Dalmia - Mechanical Lead

  • @Matthew Murzaku - Aerodynamics Lead

  • @William Wendling - Ergonomics Lead

Project Requirements

  • Modular Design

  • Optimized funnel design

  • Interface with 4in. Ducting

  • Mesh Hole Cover

Subtasks

  1. Design

  2. Sim

  3. Test Print

  4. Integration

Documentation

Powertrain Meeting 9/16:

Front intake:

  • Modular Design → removable/not permanently epoxied to aeroshell

  • Optimized funnel design → 3D splines + iterate with CFD

  • Interface with 4in. Ducting → duct adapter

  • Mesh Hole Cover → improve

Questions:

  • Kaden: thermal load + required airflow

  • Matthew: reach out for CFD help

    • Do you already have CFD boundary conditions/setup for aeroshell that I can integrate into?

      • velocity inlet at nose/static pressure outlet at radiator BCs

Cooling Research: from https://cloud.wikis.utexas.edu/wiki/x/a4WIEw

  • Cooling method: Active liquid cooling loop

  • Cold plate: Carbon fiber composite tubes epoxied to aluminum baseplate

  • Pump + reservoir: Inside dedicated enclosure near radiator

  • Loop components: pump → cold plate → radiator → reservoir

  • Fans for airflow through radiator

Radiator:

  • Radiator model: 240 mm liquid cooling radiator (2x120mm), Copper core

  • Dimensions: 280×120×54 mm

  • Fin density: 30 fpi

  • Heat: 288 cells, 6.6A, Ri = 13.5 mΩ

    • I^2Ri​ + reversible loss = 6.62^2(0.0135) + (0.6) = 1.2 W => Qpack = 288(1.2) = 350–450 W

    • Target cooling capacity: 350–450 W sustained

    • Peak cooling load: 500–600 W (safety margin)

Fans:

  • Fan model: AFB1212SH-F00

  • Fan voltage: 12V

  • Max static pressure: 0.53 in H2O (132 Pa) (datasheet)

  • Max cfm per fan: 113 cfm (spec sheet)

  • Total system airflow target: >120 cfm cold air through radiator

    • Q=mdot(cp)(​deltaT) => Vdot=Q/[rho(cp)​(deltaT)]= 400/[(1.2)(1005)(10)]​=0.033 m^3/s= 70 cfm w/ 60% margin for mesh/duct/fan losses

  • Number of fans: 2

  • Control: pwm via pump control pcb

Ducting:

  • Number of ducts: 2

  • Duct: 4” aluminum flex duct

  • Duct length: 2.1–2.3 m?

  • Number of bends: ~3 bends per duct

  • Minimum bend radius: estimate >150 mm

  • Max allowable duct pressure drop: Keep <60 Pa total

    • Darcy-Weisbach (calc around 30 Pa)

Design Constraints:

  • Allowable intake opening size and shape: By aeroshell. Ainlet = 16.67 in^2

  • Material: ASA

  • Wall thickness: 3 mm

  • Mounting surface: Curved nose surface of aeroshell

  • Interface with aeroshell: Epoxy bond + surface sanding prep. Mini CF layup

  • Serviceability: Quick-removable duct side, permanent nose side

  • Mesh and debris protection: Aluminum/stainless steel? (at intake face)

    • Pressure drop K: 1.5–3 expected

    • Open area %: >65% recommended

Flow & Performance Targets

  • Required airflow (radiator): >120 CFM

  • Duct air velocity: 3–4.5 m/s

    • A=2pi(0.0508)^2= 0.0162 m^2

    • V=Vdot/A=0.0566/0.0162=3.5 m/s

  • Available ram pressure: 135 Pa @ 35 mph (usable)

    • q=rhoV^2/2

    • @ 15 m/s : q=0.5(1.2)(15.6)^2 = 135 Pa 

  • Intake pressure recovery target: >70% recommended

  • Total intake pressure loss budget: <60 Pa

  • Radiator delta T (air): 8–12C benchmark

  • Inlet air rise allowed: <+3C above ambient (common engineering limit?)

Thermal System Requirements

  • Cooling loop power target: 350–450 W sustained

    • mdot=rhoVdot = 1.2(0.0566)=0.068 kg/s

    • Q=mdot(cp)​(deltaT)= 0.068(1005)(10)=680 W “stress case”

  • Coolant type: Water-glycol

  • Flow rate (pump): 800 L/hr maximum (D5-class)

    • coolant temp rise: Tcool​=Q/mdot(cp)​ => small (good)

  • Max coolant temp: <60C target (cell limits, battery max charge/discharge temperature is 80C)

  • Radiator inlet/outlet temp? tbd if tested, to verify heat rejection

 

Workday 9/20:

  • Intake design temporarily paused pending confirmation of aeroshell availability. Discussed composite manufacturing schedule and determined that the new shell may not be feasible on current timeline. Team is preparing a fallback plan using the existing shell until constraints are resolved.

Duct adapter:

  • Previous: exposed torsion spring presents a pinch/finger injury hazard (noted by Kaden)

  • Latch mechanism protrusion caused interference with adjacent components and may impact assembly

Current Design:

  • Connects duct adapter → intake body

  • 4" bayonet (twist-lock mechanism) adapter with 3 notches @ 120 degrees.

  • Adapter has three equally spaced hooks that interface with three slots in the intake body

  • Install motion: align tabs → insert → twist

  • Hooks capture the intake body flange during twist to provide axial retention

  • Primary retention from tab/flange engagement

  • Secondary retention from spring-loaded latch tab

  • Latch tab is mounted on pin + torsion spring

  • Latch automatically engages after twisting into locked position

  • Prevents accidental reverse rotation from vibration or handling

  • Manual release required: lift latch → twist off

  • No tools required → serviceable by hand

  • The body is wrapped by mesh + duct clamp, so the secondary lock cannot sit on the body wall; it must live on/at the flange and avoid the clamp band.

Constraints:

  • Keep the existing twist-lock interface

  • Replace only the secondary latch

  • Must be tool-less + safe

  • Must prevent reverse rotation under vibration

  • Must be repeatable and manufacturable

  • Flange OD/ID: 120 / 91 mm, thickness 4 mm

  • Notch: 18.8 mm (tan) × 6.4 mm (radial)

image-20251018-020147.jpeg

Options explored:

  1. Spring-loaded pawl (vertical drop in tab)

    • A tab (“pawl”) is spring-biased downward so its tooth drops into the bayonet notch. Lifting it releases the joint.

    • Pros: very compact, obvious lock state, prints well, one-hand use, lives entirely on flange

    • Cons: adds a spring and sliding fit

  2. Rotating safety collar (flange ring)

  3. Quarter-turn cam lever (flange face)

  4. Flip-over strap keeper (hinge on flange rim)

    • Short strap flips over and wraps the tab ear/post.

    • Cons: small hinge pin, protrudes a bit.

  5. Curved slider (Z-track lift/slide)

    • Slider rides a curved track. In LOCK it obstructs the notch, may require lift-then-slide step for safety.

    • Pros: spring-free, compact profile.

    • Cons: best placed on the body wall, packaging is tight if we must stay on the flange.

  6. C-clip in flange groove

    • Snap a wire clip into a groove after locking.

    • Cons: extra step and small loose part to manage.

Evaluation Criteria: mesh/duct compatibility (flange-only), printability (FDM clearances, simple feature shapes), ergonomics (one-hand, glove use), security (resists vibration/torque), serviceability (easy to inspect/replace), part count/hardware simplicity

 

Pawl + spring decisions/calcs:

  • Spring

    • Using McMaster-Carr 9434K163 (0.75" L, 0.12" OD, steel compression spring)

    • 5 lbf/in rate (0.87 N/mm), works for thumb actuation

    • No coil bind at 8 mm lift → safe compression range

      • Pawl lifts 8 mm, tab length 26 mm, tower height 33 mm.

      • Spring column 24 mm tall, 14 mm nests into pawl tab

      • Spring: k=0.874 N/mm

      • Full-lift force 7.4–7.9 N (1.67–1.77 lbf).

        • F=0.874×8.5=7.43 N (~1.67 lbf)

        • F=0.874×9.0=7.87 N (~1.77 lbf)

      • Compression used 8.5–9.0 mm < 10.31 mm allowable → no bind.

    • Small OD fits tower pocket

    • Spring feel: ~6 N thumb force at full lift

  • Pawl geometry

    • Tooth: 11.4 mm tangential × 3.0 mm axial

    • Radial reach 4.6 mm into 5.6 mm notch (1.0 mm clearance)

    • Lead-in face: 45 deg chamfer for smooth engagement

      • Tab matches adapter curvature; flange = 4.0 mm.

      • Shank covers flange 6.65 mm at lowest point → 2.65 mm extra bite.

      • With 8 mm lift, tab clears flange by 1.35 mm at full lift

    • Edges broken

    • Clocked to align with primary LOCK notch (theta = 0)

    • Stays inside clamp/mesh keep-out zone

  • Safety

    • Spring fully enclosed w/ retainer cap (no exposed coils)

    • No pinch during actuation

    • Geometry defaults to locked position (fail-safe)

 

Workday 10/11:

  • Rough geometry of duct adapter modeled

  • Initial twist-lock mechanism layout established

  • Basic interface with intake body confirmed

To Do Next:

  • Apply tolerances for tab engagement and clearance

  • Calculate spring compression for latch preload and travel

  • Verify fit with intake body before R2 review

  • Prepare draft for manufacturability check

 

Powertrain Meeting 10/14:

R2 Design Reviews

  • Review feedback:

    • Fix heat-set insert hole

      • 4.5 mm diameter

      • 5.5 mm depth

      • 2 mm clearance

    • Fix plunger before uploading to assembly

 

Mesh mounting reconsideration? https://cloud.wikis.utexas.edu/wiki/x/i5_vAQ (current)

Mesh redesign objectives:

  • Improve install repeatability

  • Maintain/improve airflow efficiency

  • Design must be 3D printable

  • Must fit existing 4" duct interface

  • Serviceable

Path Options:

  • Internal mesh (at duct adapter)

    • Mesh stays hidden inside adapter

    • Compatible with current airflow path

    • No external hardware required

    • Slightly harder access for cleaning

      • Concepts:

        • Snap-in mesh cartridge

          • Mesh disk is sandwiched inside a printed cartridge → Cartridge snaps inside the adapter bore → Duct still clamps normally over adapter OD → Mesh stays fully inside airflow path

        • Twist-lock mesh insert

        • Internal snap ring channel

  • Front-service mesh (intake face)

    • Mesh easily replaceable from nose opening. Highly serviceable

    • Must manage aero drag + visibility. Needs clean mounting interface

      • Concepts: Snap-on mesh bezel, bolt-on faceplate, hinged mesh door, mesh cartridge slot, rubber gasket + mesh press fit

 

Workday 10/18:

  • Began geometry integration of NACA intake onto curved aeroshell nose

  • Created mounting interface directly from aeroshell surface using a zero-offset surface to ensure fit to composite nose geometry

  • Upload intake bodies to assembly to begin packaging checks

  • Two CAD concepts:

    • 1 → Fully conformal: inlet and lip follow aeroshell curvature

    • 2 –> Flat-lip ('22)

  • Nose-side permanent, duct-side removable

Next Steps:

 

Mounting Architecture to Aeroshell
Permanent nose-side + removable duct-side modular system

→ heat set inserts

 

Powertrain Meeting 11/04:

Design review:

  • double clearance between twist-lock tabs and flange (fit issue)

  • add flange surface area → better clamping pressure + bonding area

  • rivet consideration for epoxy clamping (temporary during cure)

  • back screws not reachable → revise geometry

  • reCAD both intakes + exhausts for nextbreak inlet updates

  • define SolidWorks mates

  • extend duct clamp clearance + adapter length

Revisit: mesh redesign

  • internal snap in cartridge

    • a printed ring that sandwiches a circular mesh disk between inner and outer lips, then snaps into the adapter bore just upstream of the clamp land

 

Workday 11/08:

  • Worked on design review corrections from ptn meeting

  • Updated intake and exhausts finished -> push to bild

  • Need to: mesh revisit

 

Lock-In 11/13:

Mesh design:

 

Spring calcs:

  • Spring compression (travel) = 7.61 mm

  • Post (finger) diameter = 2.36 mm

  • This is finger-actuated, so we want a reasonable finger force.

Aim for about 8 N of force at full compression:

k (spring rate) = Force / Deflection
k = 8 N / 7.61 mm
k = 1.05 N/mm

So design target:
spring rate about 1 N/mm

Need some clearance between the spring ID and the 2.36 mm post:

  • Spring inner diameter ID = 3.0 mm

  • Wire diameter d = 0.5 mm

  • Mean coil diameter D = ID + d = 3.0 + 0.5 = 3.5 mm

  • Spring index C = D / d = 3.5 / 0.5 = 7 (

k = (G * d^4) / (8 * n * D^3)

n = (G * d^4) / (8 * k * D^3)

Solve:

  1. d^4 = 0.5^4
    0.5^2 = 0.25
    0.25^2 = 0.0625
    So d^4 = 0.0625

  2. D^3 = 3.5^3
    3.5^2 = 12.25
    12.25 * 3.5 = 42.875
    So D^3 = 42.875

  3. Numerator = G * d^4
    = 79,000 * 0.0625
    = 4,937.5

  4. Denominator = 8 * k * D^3
    Take k = 1 N/mm for the calc:
    8 * 1 * 42.875 = 343

  5. n = 4,937.5 / 343
    n is about 14.4

Need about 14 active coils.

k = (G * d^4) / (8 * n * D^3)
k = 4,937.5 / (8 * 14 * 42.875)
8 * 14 = 112
112 * 42.875 = 4,803 (close enough)
k = 4,937.5 / 4,803
k is about 1.03 N/mm

Force at 7.61 mm:

F = k * x
F = 1.03 N/mm * 7.61 mm
F is about 7.8 N

Solid height (coils fully stacked) is roughly:

L_solid = n * d
If n = 14 and d = 0.5 mm:
L_solid = 14 * 0.5 = 7.0 mm

Compress the spring by 7.61 mm in use, so free length must be greater than 7.61 + 7.0

Choose L_free about 17 mm
Length at full compression = L_free - deflection
= 17 mm - 7.61 mm
= 9.39 mm, which is still safely above the 7 mm solid height.

 

use: McMaster-Carr

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