×

### Let's log you in.

or

Don't have a StudySoup account? Create one here!

×

or

## Thermodynamics 1, Chapter 1 & 2 week 1

by: Jeffrey Severino

20

0

7

# Thermodynamics 1, Chapter 1 & 2 week 1 ME 236

Marketplace > University of Hartford > Engineering and Tech > ME 236 > Thermodynamics 1 Chapter 1 2 week 1
Jeffrey Severino
University of Hartford

Enter your email below and we will instantly email you these Notes for Thermodynamics I

(Limited time offer)

Unlock FREE Class Notes

Everyone needs better class notes. Enter your email and we will send you notes for this class for free.

These notes cover what was in the lecture on 5.19.16 All diagrams are from Fundamentals of Thermodynamics 8e by Claus Borgnakke, Gordon John Van Wylen, and Richard E Sonntag
COURSE
Thermodynamics I
PROF.
Dr. Ribarov
TYPE
Class Notes
PAGES
7
WORDS
KARMA
Free

## Popular in Engineering and Tech

This 7 page Class Notes was uploaded by Jeffrey Severino on Friday May 20, 2016. The Class Notes belongs to ME 236 at University of Hartford taught by Dr. Ribarov in Summer 2016. Since its upload, it has received 20 views. For similar materials see Thermodynamics I in Engineering and Tech at University of Hartford.

×

## Reviews for Thermodynamics 1, Chapter 1 & 2 week 1

×

×

### What is Karma?

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 05/20/16
CHAPTER 1 CONCEPT OF ENERGY Macroscopic: Things we can see - (Classical Thermodynamics) Microscopic: Statistical Thermodynamics – (Energy being quantized) A Microscopic amount of mass can present energy in the following forms: - Internal – internal structure - Kinetic Energy-Related to motion - Potential Energy-External forces acting on this mass - Rotational Energy-Rotational force TotalEnergy=I+KE+PE+ℜ=U+KE+PE+ℜ Dividingbymassgivesus:e=E /m=u+ke+pe+ℜ=u+1/2v +gh+1/2I ꙍ 2 ¿ Internal Energy (macroscale)-similar set of energies (associated with macroscale motion of individual molecules .U=U external molectranslatio∫molecule Where: U externalmoleculeermolecular forces (PE sum) U translationKE of molecule) U molecule Internal/atomic structure ∫ But there is a difference between intermolecular forces High Density (ρ) =close spacing = high Low Density (ρ) =loose spacing = weak molecular interaction molecular interaction U ≈0 In the limit of a very low ρ (rarified gas) => ext - No external forces, molecules are too far apart, so the forces are little between them - Ex: leaving the earth’s atmosphere Translated Energy depends only on mass & velocity of center of mass of the molecule Internal Energy depends on the molecules internal structure We rewrite the energy eqn: .U=U molecule rotationvibrationatoms ∫ There are three principal vibration modes of the H2O molecule While we evaluate the energy of the molecule, we refer to these energy modes as Degrees of Freedom [(d.o.f) -> modes of energy] Atomic/Molecular Structure Element or Compound Degrees of Freedom Monatomic molecule He 3 (x,y,z) Diatomic molecule O2 6 (x,y,z) rotation (x,z) vibration (y)-> causes ‘stretch’ Triatomic molecule H2O 9 (x,y,z) translation: 3 rotation: 3 vibration: 3 Most complex polyatomic molecules are 3-D structures that have multiple vibration modes, each of which contributes to the energy storage capabilities of the molecules Phases: solid, liquid, vapor (gas) State: specific condition, expressed by a unique set of properties such as Pressure, Temperature and Density - Two independent properties can define a state - Intensive properties independent of mass (P,T,ρ) - Extensive properties dependent on mass (m,V,E) Process: a change of substance beginning at state 1 to final state 2 through a continuous variation of state. 1) Process path: specific succession of states that which this happens - Device behaves as a process equation/device equation ex: heating a cup without container; exposes cup to atmospheric pressure-> constant pressure process => ”isobaric” process 2) Heating Air in constant volume container => “isochoric” process 3) Air compressed in a piston, cylinder walls are at constant temperature => “isothermal” process 4) Air compressed in an insulated piston (no cooling/heating) => “adiabatic” process Cycle: a process path, that ends in the initial state, it can be a complex process or a series of simple processes. - Cycles do not change the working substance - However, outside of the cycle; the surrounding environment may change while the working substance is at different conditions during this cycle=>Net effect is energy conversion process ex)engine needs surrounding! CHAPTER 2 PROPERTIES OF A PURE SUBSTANCE Pure Substance- has homogeneous & invariable chemical composition; may exist in one or more phases A mixture of gases is considered a pure substance *as long as there is no phase change Phase Boundaries: 1) Saturation Temperature – temperature at whiche vaporization takes place at a given pressure (“boiling temperature”) 2) Fusion Line- border between solid and liquid phases 3) Sublimation Line- border between solid & vapor phases 4) Triple Point- only P,T combinations where all three phases exist @ the same time (T=0.001 degrees Celcius, P=0.6113 kPa)=> water *(P of atm = 101.3 kPa) bellow Triple Point is no liquid 5) Vaporization Line- border between liquid and vapor phases Critical Point for H2O is at P=22.09 MPa, this is where vaporization stops. CHAPTER 2 PROPERTIES OF A PURE SUBSTANCE The P-V-T surface: CHAPTER 2 PROPERTIES OF A PURE SUBSTANCE X=0 -> Saturated Liquid X=1-> Saturated Vapor Sup. Vapor->Superheated Vapor (point where no liquid is left, only vapor as a result from the liquid being “superheated”) Steam Tables give the difference between the given temperature and the saturated temperature for the same pressure Superheated Vapor Region: Table B.1.3 Compressed Liquid Region: Table B.1.4 Saturated liquid/Saturated Vapor-> as f(T) -> table B.1.1 as f(P) -> table B.1.2 Saturated solid/Saturated Vapor-> as f(T) -> table B.1.5 Two Phase States If: Saturated liquid = “f” Saturated steam = “g” Then: TotalVolume=V=V +V liq vapm ∗liqm fV vap g V m liq m vap Dividingby massgivesus:v= = V f V g m m m m vap Quality,x= = (−x V )xfV g m CHAPTER 2 PROPERTIES OF A PURE SUBSTANCE VfgV −g =¿f=V +x∗V f fg Example: Find overall specific volume (v) if a saturated mixture of water at 200 degrees C, x=70% 70%=0.7 m 3 m 3 B1.1→V =f.01156 kg,V g0.12736 kg 3 3 3 v=(1−x ) +x∗V = 1−0(7 0.0)156 m +0.7∗ 0.12736 m = 0.0895m f g ( kg) ( kg ) kg

×

×

### BOOM! Enjoy Your Free Notes!

×

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

Steve Martinelli UC Los Angeles

#### "There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Jennifer McGill UCSF Med School

#### "Selling my MCAT study guides and notes has been a great source of side revenue while I'm in school. Some months I'm making over \$500! Plus, it makes me happy knowing that I'm helping future med students with their MCAT."

Bentley McCaw University of Florida

#### "I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Parker Thompson 500 Startups

#### "It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!
×

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com